Team AMC,
Have you guys added any traction improvement devices to their rear axles?? I was looking into doing something this summer when I do my axle ratio change. I drive the car everyday on the street.
I am running a 4.0 with an AX15 and a 242 case. I was thinking about going 3.07 gears for economy but was also contemplating 3.55s and using 5th gear more. Any thoughts??
Edited for sleepiness. :rotfl:
Sorry all. By traction improvement I meant, posi, detroit, air locker etc. I thought it was a given Eagles weren't over powered ;)
Quote from: mach1mustang351 on December 17, 2011, 01:40:34 AM
Sorry all. By traction improvement I meant, posi, detroit, air locker etc. I thought it was a given Eagles weren't over powered ;)
Haha, okay. Sorry. It's late, and for some reason I thought you meant something different.
I'm not sure what would fit with an Eagle axle, but that would be a great investment. Open differentials suck :(.
Quote from: Sunny on December 17, 2011, 01:50:02 AM
Quote from: mach1mustang351 on December 17, 2011, 01:40:34 AM
Sorry all. By traction improvement I meant, posi, detroit, air locker etc. I thought it was a given Eagles weren't over powered ;)
Haha, okay. Sorry. It's late, and for some reason I thought you meant something different.
I'm not sure what would fit with an Eagle axle, but that would be a great investment. Open differentials suck :(.
Haha this made my night. I guess it was kind of a confusing wording. Open differentials are good going around corners... here in Alaska with glare ice roads I would love something in the back of that car locking the two wheels together. Just checking if someone already did it.
I can't imagine it would be any different than doing it on a Jeep.
I installed a Chrysler 8.25" axle from a 98 Cherokee. For $150 and my time, I gained an axle nearly as strong as a Dana 44, the gear ratio I wanted to switch to and Trac Lok differential. The Trak Lok is an OEM limited slip option on Jeeps. It's not the same as a locker but will do fine unless you are planning on doing some serious off roading with large tires. I have yet to spin one tire plus they are rebuildable. If you want to keep your AMC 15 rear axle I believe a locker for a Dana 35 will work.
http://www.jpmagazine.com/techarticles/drivetrain/154_0910_jeep_locker_overview/viewall.html
My 1992 Jeep Cherokee is a 4.0 AX15 NP231 with 3.55 gears and 235/75R15 tires. Thats the same tire size I use for all my Eagles. It requires slight changes inside the fender flares, but its the largest size you can put on without any external changes. I had two identical automatic station wagons with different axle ratios and there was a 4 mpg difference, but I do not think you will see that significant of a difference with a manual vehicle.
I found the gearing to be perfect. I got about 25 MPG on the highway at 75 mph, which is quite respectable for a Cherokee at that speed. At 75 mph I would have to often downshift into 4th to maintain my speed up hills. If I was to change it, I would actually go a next size lower 3.73s. If you go with 3.07s, your 5th gear will become useless and your first gear will be less desireable in traffic. I often start in second in that Jeep but appreciate the low first there when I need it. Your engine needs to be turning at higher RPMs to put out enough power to maintain highway speeds. My opinion is to stick with the 3.55s.
I personally call them limited slips if they have a smooth clutch action, soft lockers if they are centrifugal units like the popular powertraxx models, and hard lockers if they are cable shifted or otherwise fully engaging lockers. A factory installed limited slip differential is the best option for most Eagles. A Ford Explorer axle is the best choice to get a limited slip and rear disc brakes. I'm using a Jeep Cherokee Dana 44 with factory limited slip and Jeep Grand Cherokee disc brakes, but thats hard and expensive to find in comparison to the Ford axles. The easiest axles to find are Chrysler 8.25" but I haven't seen many with a limited slip. They are much stronger than the Eagle axles because of the stiffer axle tubes. I still avoid them, since I won't buy a C clip axle after having three wheels fall off in the rear of an Eagle. The biggest advantage to the Dana 44 is that the wheel remains attached even if the axle shaft breaks.
I have a centrifugal unit in my Jeep Scrambler. Its effective, but it has a noticeable effect in curves. My sister refuses to drive it because of the soft locker. Their biggest advantage is that they can be installed quickly and easily. No change to the carrier is necessary. As a wheel loses traction and the wheel begins to spin much faster relative to the other, the centrifugal force locks the two halves together. It clunks together and often causes an audible tire screech. The clutches in a limited slip differential are much smoother and less likely to scare the driver, but in some ways that makes them less effective than a soft locker.
A hard locker is much more expensive and harder to install. The one I want to buy for my 401 5 speed SX4 is electric. Its a limited slip until you push the button and then the axles are fully locked together. My Rubicon has this option front and rear and I absolutely love them. Most of us would never install one since they're worth more than the average Eagle. I think a soft locker costs about 300 dollars and a hard locker 1200 to 2000 dollars. A limited slip differential is expensive unless you buy a whole axle with a factory unit already installed.
i do contract work on vehicles had a jeep guy wanted one of these "powertrax lockright lockers" installed in his warngler,, was not hard to install,, parts were reasonable,, looks verry well made he's been running it for around 3 years and had NO issues to report,, his daily driver with light to moderate trail use,,
http://www.richmondgear.com/powertrax/lockright.html
they list one for most ALL AMC vehicles,,
Quote from: n9xvt on December 17, 2011, 11:31:17 PM
i do contract work on vehicles had a jeep guy wanted one of these "powertrax lockright lockers" installed in his warngler,, was not hard to install,, parts were reasonable,, looks verry well made he's been running it for around 3 years and had NO issues to report,, his daily driver with light to moderate trail use,,
http://www.richmondgear.com/powertrax/lockright.html
they list one for most ALL AMC vehicles,,
Good information, thanks a lot. This sounds liek it works a lot like the Detroit style locker. I am not planning on any off roading but I do like in AK where i deal with Ice. The car works well in 4wd but I plan on changing gears this summer and I can't ever stop myself from the "while I'm in there" thinking.
I would also go limited slip. better for normal driving and ice and snow driving.
I thought my Eagle WAS A Traction Improving Device!
Quote from: milliard431 on December 18, 2011, 07:21:02 PM
I thought my Eagle WAS A Traction Improving Device!
I have had no issues either when in Full Time 4 wheel but it's that darn "while I'm in there" mindset...
Quote from: mach1mustang351 on December 18, 2011, 07:30:31 PM
but it's that darn "while I'm in there" mindset...
That's the best mindset to have. ;D
A few people like these ones too. I asked them a long time ago if their Dana 35 would fit an AMC 15 but never got a reply.
http://www.aussielocker.com/index.php/
It will work in an '80 up Model 15, because if you look at the web of the diff housing, you will see 35C cast into it.
I got that information confirmed. I'm thinking limited slip would be the best option for the snow and ice. I dont want to make the car to capable as I would be tempted to venture off the paved road. I have been able to restrain myself so far...
This project became more serious today when I almost couldn't leave a parkign lot because of a combination of deep snow steep uphill and having to stop at the top to look for traffic. The snow was piling in front of the wheels so bad it was stalling the car. I had to back up some and put it 4LO. Lower gears to match the AX 15 and the 235/75/15s needs to happen.
You're not close to Seattle by any chance? I have a pair of axles with too low of gears that I put the rear of into my Spirit Pre-runner temporarily (I have to pull the rear out)
Yes and no. I am in Anchorage, AK... so most of our goods come from Seattle. What is the story on your axles?? If it's something I can swing it may be worth figuring out some shipping.
I bought an Eagle for parts (I was going to fix it till I found out it had black mold and no floor/frame under the carpets) and put the rear axle in my Spirit before discovering it wasn't 3.08 ratio as I had assumed. Rear needs pinion bearing and seal. Front looks/feels barely used. Keeping the rest of the suspension to turn the Spirit into a Pre-Runner this summer.
A Soft Locker is part of the Detroit Locker name, usually seen as Detroit Soft Locker. Sometime 10-15 years ago, Eaton did something to make the locking action not as severe, hence the Soft Locker.
Luchbox Locker- One of the automatic locking lockers that replaces the spider gears in an open (and sometimes limited slip) differential case. Powertrax No Slip, Aussie, LockRite, etc.
Full case locker- An automatic locker that replaces the whole differential case. Detroit Locker, Grizzly Locker, etc.
Selectable Locker- A locker that replaces the whole differential case. These lock the 2 axle shafts together giving full traction to both tires when activated by, electricity, cable, air, or a combo of the 3 (The electric OX locker for one). When not actuated, it acts as an open differential. There are variations like the Rubicon D44, which are limited slips, but are fully locked when actuated. Ox Locker, Eaton E-Locker, ARB Air Locker, etc.
Limited slip- A traction aiding device that sends power to the other wheel when one wheel starts to slip. They work by using clutch packs, cones, or gears.
I took the D35 out of my Cherokee and put it under an Eagle. It was 3.55 with limited slip. The Eagle has a 5 speed and 30X9.5's. You can get just about any type of locker for the D35. If it fits in the D35, it'll fit in the AM15.
For snow driving, I would prefer a selectable locker. Keep it open while driving down the road on ice/snow, and lock it when it gets deep. Next choice would be a limited slip.
I appreciate all the feedback on the situation. I have been doing my research and I didn't realize the front diff situation for a gear change. I may have to put off any work until I can find the illusive 4 cyl carrier to run the 3.55s I need... sigh...
At the swap meet I was looking through some of Bell Offroad's stuff and they have some pretty sweet Yukon and Grizzly lockers. I think I might buy a set before next Winter. I can't believe they have stuff for AM20s and Model 35s. This is great. :)
I found 1 D30 3.54 for the front off from car-parts.com ($165 shipped). My son bought it. He has the 2.73 right now. For the price of a new set of gears, he got the whole axle assembly. I'm going to take both differential cases and measure them to see what the difference is, there shouldn't be any according to the Dana info I have. It's the to common 2.35 differential case that throws everything off from what I have researched so far.
I haven't seen a locker company that doesn't make a locker for the AM(C)20 or D35/AM15.
Quote from: PR1AWRet on March 10, 2012, 07:55:13 PM
There are variations like the Rubicon D44, which are limited slips, but are fully locked when actuated.
Only 2006 and older TJ Rubicons are limited slip. The 2007 up JK Rubicons are open differential when not electrically locked.
Also all "Unlimited" long wheelbase TJs came with a rear Dana 44 as standard equipment, while most short wheelbase non-Rubicon TJs did not. Its a great axle to swap into an Eagle if you can find one because it's rear disc brakes with 5x4.5 lugs. The Rubicon transfer case is also very desireable because it is the only factory equipped transfer case to have a 4:1 low range, all the others have 2.7:1. I also got my NSG370 6 speed from a wrecked 2006 Rubicon. I ended up buying one because I figure I'll have a goldmine of Eagle parts if it ever gets wrecked.
My 80 Scout and 06 Rubicon have the same rear axle and tires, but the limited slip is a huge difference. The extreme turn, sharp uphill, and gravel makes the Scout spin and sputter every time I turn into my driveway. Without momentum it has to back up and start again. The Rubicon's limited slip never misses a beat no matter how slow or fast I make the turn.
Quote from: captspillane on March 12, 2012, 01:01:36 PM
Quote from: PR1AWRet on March 10, 2012, 07:55:13 PM
There are variations like the Rubicon D44, which are limited slips, but are fully locked when actuated.
Only 2006 and older TJ Rubicons are limited slip. The 2007 up JK Rubicons are open differential when not electrically locked.
Also all "Unlimited" long wheelbase TJs came with a rear Dana 44 as standard equipment, while most short wheelbase non-Rubicon TJs did not. Its a great axle to swap into an Eagle if you can find one because it's rear disc brakes with 5x4.5 lugs. The Rubicon transfer case is also very desireable because it is the only factory equipped transfer case to have a 4:1 low range, all the others have 2.7:1. I also got my NSG370 6 speed from a wrecked 2006 Rubicon. I ended up buying one because I figure I'll have a goldmine of Eagle parts if it ever gets wrecked.
I have a NV241 OR, but it's going into my Jtruck (It'll need it with 52" tires)
Any one remember the AMC sure grip axle? They were posi not sure if they were in eagles though. I do believe they would bolt up.
Quote from: 85AmCfreak on March 12, 2012, 11:17:28 PM
Any one remember the AMC sure grip axle? They were posi not sure if they were in eagles though. I do believe they would bolt up.
It was called a Twin Grip. It wasn't listed as an option, but back then if you wanted to order something not offered as an option on a new car, it was a lot easier than then it is now. So, there is a very small chance an Eagle or two left the factory with rear Twin Grip, but no evidence of it happening.
The only thing I would worry about is the integrity of the 2 piece axle shafts with a limited slip or locker. With the age of them and corrosion on the splines it seems they would strip pretty easy. I know the axle in my sons car was really corroded and one was stripped at the hub, hence a 95 D35 went in it with a limited slip. If the car isn't staying stock I'd put a D35, Chrysler 8.25 or D44, from a XJ Cherokee, in it. Even if it was staying stock, I'd pull the rear axle and store it some place so the axle shafts wouldn't strip as they are really hard to come by.
Now that ya mention it I was thinking of using the 8.25 or the D44 as a replacement the only thing I was running into was the gear ratio, I really want to try the XJ's 3.55 ratio in an eagle............. anyone ever try it?
Quote from: PR1AWRet on March 13, 2012, 11:03:59 AMIf the car isn't staying stock I'd put a D35, Chrysler 8.25 or D44, from a XJ Cherokee, in it.
If you are pulling it anyways, I'd just go with a D44.
D35's are relatively weak.
I've seen plenty of them break on trails.
Especially running any oversized tires.
It's a pretty well documented fact on most jeep forums.
The axles on them are just way too thin to be any good.
Quote from: Sunny on March 17, 2012, 08:53:18 AM
Quote from: PR1AWRet on March 13, 2012, 11:03:59 AMIf the car isn't staying stock I'd put a D35, Chrysler 8.25 or D44, from a XJ Cherokee, in it.
If you are pulling it anyways, I'd just go with a D44.
D35's are relatively weak.
I've seen plenty of them break on trails.
Especially running any oversized tires.
It's a pretty well documented fact on most jeep forums.
The axles on them are just way too thin to be any good.
I agree 100%! You can build the others but the cost isn't worth it. D44 is a great axle. I had it in a s-10 blazer with a 305 and 35inch swampers on it and i broke all sorts of stuff but i never broke my used junkyard d44 axle. but then again i always run cheap u-joints so they are my weekest link on my drive train.
Quote from: 85AmCfreak on March 17, 2012, 06:44:59 AM
Now that ya mention it I was thinking of using the 8.25 or the D44 as a replacement the only thing I was running into was the gear ratio, I really want to try the XJ's 3.55 ratio in an eagle............. anyone ever try it?
People have done it and the factory used that ratio, with the 4 cylinder's though their math rounded it to 3.54, you can definitly get the 8.25 in a 3.07 or a 3.55 (as I have both), which pair well with a 4 cylinder 3.54 frontaxle or an optional 3.08 front axle
I have an 8.25 with 3.07 going into my Eagle wagon soon. The D35 would've been fine because unless you are running big tires or seriously offroading, it handles quite a bit. I still haven't killed mine with 33" tires and rolling up on 200,000 miles in my MJ.
I think I have decided on doing a D35 swap with 3.55 for the rear but I still need the illusive 4cyl front axle. I will keep looking. Any leads appreciated.
Anyone ever use the 3.55 with a 6 cylinder?? I know it must scream on the highway.....
I have the 3.55 axles on my Wagon, with 258, 3spd. auto TF998. I swapped in a TF998 with lock-up because it scared me soo much down the highway. With 235/75 R15 tires, the lock-up, and now 4.0 head and EFI, I can hit 70 at around 2500rpm. With the Carter and non-lockup, I was very close to 3000rpm.
Quote from: carguy87 on March 20, 2012, 11:34:41 AM
I have the 3.55 axles on my Wagon, with 258, 3spd. auto TF998. I swapped in a TF998 with lock-up because it scared me soo much down the highway. With 235/75 R15 tires, the lock-up, and now 4.0 head and EFI, I can hit 70 at around 2500rpm. With the Carter and non-lockup, I was very close to 3000rpm.
Witch ones are lock up?
My rig is a 4.0 with an AX15. The 355 is factory on the cherokees with the same setup. Should be right... I hope.
3.55 is perfect for an AX15 or T5.
Actually the standard XJ gear ratios were 3.07 for manual and 3.55 for automatic. With 3.07 at highway speeds you are stuck in an awkward spot where its a little too high for 4th and a little too low for 5th, and you are constantly upshifting or downshifting. Its annoying. With 3.55 gears you won't have that problem and you can still cruise at 85 or 90 mph if you're so inclined.
The overdrive in the XJ's AW4 makes 3.55 perfect for an automatic too, but without an overdrive its too low of a gear. 3.07 works well with the stock TF998 if you drive aggressively and 2.72 is perfect if you want a mixture of performance and fuel economy. Most "towing" package Eagles had 3.07.
Quote from: captspillane on March 21, 2012, 01:01:00 AM
With 3.07 at highway speeds you are stuck in an awkward spot where its a little too high for 4th and a little too low for 5th, and you are constantly upshifting or downshifting. Its annoying.
This got my attention. My Eagle has 2.73 gears with an automatic and I'm thinking of doing a T-5 swap after I rebuild the engine to fit my specs. I've thought about dropping the gearing to 3.xx but would I even be able to use 5th gear if I leave the differentials alone? All I ever do is freeway driving on flat pavement.
Quote from: DaemonForce on March 21, 2012, 06:00:11 AM
Quote from: captspillane on March 21, 2012, 01:01:00 AM
With 3.07 at highway speeds you are stuck in an awkward spot where its a little too high for 4th and a little too low for 5th, and you are constantly upshifting or downshifting. Its annoying.
This got my attention. My Eagle has 2.73 gears with an automatic and I'm thinking of doing a T-5 swap after I rebuild the engine to fit my specs. I've thought about dropping the gearing to 3.xx but would I even be able to use 5th gear if I leave the differentials alone? All I ever do is freeway driving on flat pavement.
Maaaaaybe, depending on the overdrive gear. It's a 1.96 final ratio at .72 OD and 2.34 at .86 OD 5th gear. If you have the .86 overdrive it's doable.
Quote from: DaemonForce on March 21, 2012, 06:00:11 AM
My Eagle has 2.73 gears with an automatic and I'm thinking of doing a T-5 swap. Would I even be able to use 5th gear if I leave the differentials alone?
I consider 2500 RPM's to be the minimum RPM needed when the engine is under full load going up a hill or trying to maintain a speed higher than 70 MPH. Sometimes it's more efficient to coast at a higher gear at idle, but then you would have to downshift to get efficient power from the engine under load. 2500 RPM is then considered the minimum RPM necessary to stay in that gear under load. Likewise it is approximately the RPM you'll have the engine at in the new gear after you've upshifted while accelerating up a hill. Keep in mind that most of us memorize shift points in mph because we don't have working tachometers.
This table shows shift speeds corresponding to each gear of a T5. A four speed is nearly identical except that it missing the fifth. The table shows that you need to be going at least 64 mph to stay in fifth with 3.54 gears. It says you need to be going at least 74 mph to consistently stay in fifth with 3.07 gears. That works pretty well but it plagues the trip with many more annoying downshifts to fourth along the highway. It says that you need to be going at least 97 mph to shift into fifth with 2.35 gears. Good f rickin lord. That's outrageous. It also says that first gear with 2.35 gears is almost exactly like starting in second with 3.54 gears.
You can drive the car just fine with 2.72 gears but its harder to drive because its more likely to stall. The last person who drove my 2.35 T5 SX4 was left in tears because they couldn't stop stalling. That same person drove my other vehicles without a problem. The shifts have to be much longer and put more wear on the clutch. You will not use 5th gear except to coast downhill. If you look at the chart it says you'll be at 83 mph at 2500 RPM in 5th. That is not a high enough RPM to produce enough power to keep an Eagle rolling on level ground at that speed.
The minimum speed per gear in mph while at 2500 RPM with a CJ T5 (4.03 first/ 0.86 fifth) and 205/75R15 tires:
Gear- 3.54- 3.07- 2.72- 2.35
1- 13.66- 15.80- 17.83- 20.64
2- 23.23- 26.86- 30.32- 35.09
3- 36.70- 42.44- 47.90- 55.44
4- 55.05- 63.66- 71.85- 83.17
5- 64.02- 74.02- 83.55- 96.70
When you are saying that 2500 rpm is minimum to produce enough power to maintain gear. Are you assuming stock 4.2L? I assume with upgrades that the rpm could be reduced, take my setup for instance; 4.2L block .030" over, 4.0L head milled ported and polished, MPI, and 60KV ignition coil running on 30lb/hr. injectors. I believe I could drop that number safely to 1800rpm. I pulled a 9ft. U-haul trailer loaded up with my most precious 6ft. long tool box fully loaded(probably tipping the payload capacity) but I was still able to cruise at a comfortable 2200 rpm up and down hill on the expressway. Just a curiosity, would the weight difference in a SX/4 and Wagon be enough to change that number as well?
Its just a reference point for comparison. Its alot easier to relate to than an expression of ratios. Its a good reference chart for any car, any size, any engine, any horsepower, any hill.
Every gasoline engine has a similar RPM range and a graphically similar power and torque curve. At 500 RPM a 401 V8 is almost as useless as an Iron Duke. At 10,000 RPM both an Iron Duke and a 401 will explode.
If in 5th in my SX4 you can go 95 MPH at 2500 RPM then you can go 19 MPH at 500 RPM or 190 mph at 5000 RPM. The engine won't mind. Any RPM is fair game in any situation, but obviously people consistantly use a much more narrow practical range of speed and RPM for any given gear.
That's true, I chose 2500 RPM because I'm talking about 4.2, 4.0, and 2.5 Eagle engines with stock or near stock camshafts. A Subaru Forester has a tiny engine that is set up to operate at a much higher range of RPM's. That would need a totally different reference RPM closer to 3500. Likewise my four speed turbodiesel Scout has a very different target RPM. A drag race car isn't designed for stop and go city traffic, it's designed to operate exclusively in its high power low longevity RPM range.
My actual "gearing calculator" is an excel spreadsheet showing several reference RPM's, every tire size I own, and every Jeep and Scout transmission I own. Its huge. My immediate family owns 41 cars and I have information for all of them. It took me several days to create the spreadsheet.
I only typed one tiny sampling here to demonstrate the effect of 2.35 versus 3.54 in an Eagle. It takes alot more information to decide what gear ratio you want in your car.
Its much more concise if we only talk about stickshift Eagles and stock Eagle engines with tires similar in size. I can tell you that 3.54 is a perfect match for a T5 or AX15, 3.07 is nearly as good a match and sometimes a better match if you have a different driving style than me, and 2.35 is no good for anyone anywhere. If you have a four speed 3.54 is too low. It will give you a top speed with the engine screaming around 80 MPH. You should use 2.72 or 3.07.
Quote from: captspillane on March 26, 2012, 02:58:28 AM
my four speed turbodiesel Scout
I have a 1966 800 and I've thought about this. Have you posted about it or have pics?
Sorry not trying to change topics. Also posting to follow topic. But Scouts do make me smile!
Still no progress on my end on this project. I am waiting on tackling anything until I know for sure I can get my 3.55s up front which as we have covered in dept other threads requires the 4 cyl front axle. Not a lot of AMC donor cars here in AK so this may be tough situation for me.
Yes I have posted about my 1980 Scout. It is currently my daily driver until my primary SX4 is complete. I bought the Scout because it came with a spare turbodiesel engine and it was mechanically sound with lots of rust repair already complete. I've since purchased a second long wheelbase Scout with Terra pickup truck cap.
The SD33T has very similar dimensions and output, both horsepower and torque, to a stock AMC 258. Its underpowered for the Scout but its perfect for an Eagle. I'll be converting the Scout to a 6.2L GM diesel or a Cummins diesel. The SD33T will be mated to a NV4500 five speed, with a special IH North adaptor kit, and then installed in an Eagle.
Here is my project thread.
http://forums.amceaglenest.com/index.php?topic=36383.0
Quote from: standup650 on March 26, 2012, 09:02:01 AM
Quote from: captspillane on March 26, 2012, 02:58:28 AM
my four speed turbodiesel Scout
I have a 1966 800 and I've thought about this. Have you posted about it or have pics?
Sorry not trying to change topics. Also posting to follow topic. But Scouts do make me smile!
You need more length under the hood. (late model Scouts came stock with the SD33 and '80 came with SD33T) 4 cyl Nissan turbo diesel would fit better. The 6 cyl is used in Full size Jeeps except in the US.
Back to the ratios:
Determine what speeds you will need to drive at the most (for example, we have 70 mph zones on the highway here and spots where it's like LA in rush hour).
What loads? (I often haul trailer or heavy loads)
What motor? What's it's power curve?
Tire size?
Nope, you don't need more length under the hood. It fits. The other thread talks about that. I own a 1980 turbodiesel as my daily driver.
Realistically all the thought and figuring in the world doesn't make much difference with the gear ratios. There's only four choices for an Eagle, and one of them is obviously junk. If your car is roadworthy (I don't consider drag racing cars roadworthy) then its going to work with the three choices.
All three of them work fine for any engine and any camshaft available. It's all preference from there. I drove my 2.35 T5 SX4 for several months with just some mild griping.
I meant the early Scout needs more underhood length to fit in a 6 cyl Nissan diesel like the Scout II (they quit calling it that before 1980). They mostly came with slant 4s (304 IH with 1 bank cut off) I did a 6 cyl 200 Ford swap into one and the firewall had to be notched to fit.
As for gears, tires make a huge difference in what ratio you'd want. Slammed lowrider would want the taller gears, even with an O/D.
As for ratios, I found out the '80 I parted had an oddball one. 3.31 with class 3 tow package (Is there a full list on Eaglepedia?)
2.37, 2.72, 3.08, 3.31, 3.54, 3.73 and 4.10. Any 4.56s? Any missing?
Quote from: carnuck on March 28, 2012, 03:48:49 AM
As for ratios, I found out the '80 I parted had an oddball one. 3.31 with class 3 tow package (Is there a full list on Eaglepedia?)
2.37, 2.72, 3.08, 3.31, 3.54, 3.73 and 4.10. Any 4.56s? Any missing?
I don't believe as such, but the 79-83 parts catalog lists a whole mess of available AMC 15 and 20 ratios. (http://www.amceaglenest.com/~iowaeagl/guide/index.php?title=Group_9_Axles_--_Propeller_Shafts)
As far as I can tell (F/R)
2.35/2.35 (20:47/17:40)
2.72/2.73 (18:49/15:41)
3.07/3.08 (14:43/13:40)
3.31/3.31 (13:43/13:43)
3.54/3.54 (13:46/13:46)
...Those are the factory Eagle ratios offered. The lowest gears (4.xx) are available aftermarket for CJs; I don't have any Jeep TSMs available to see if there were other options from AMC.
The 3.0x and 3.54 gears are easy to come by for replacement but 3.31, 2.7x and 2.3x sets are hard to find. They exist, aren't necessarily more expensive, but are just harder to find.
Are these 'soft lockers/centrifugal' parts along the same lines as the 'Lunchbox Lockers' I have read about? I'd like to get a little bit better traction in my '80 sedan, do not have the resources easily at hand to do major welding mods in the way of axle swaps, and am liking the fuel mileage (albeit pokey) performance of the long-legged gearing. The 2-speed transfer case takes care of tall gearing off-road for my needs. Please if I may ask, what and who is a source for these devices? I'm sure I could install it myself, reading you keep the same carrier and do not have to disturb crown/pinion during the project. How noticeable is the unit on the road, does the device make the Scrambler jump sideways badly in a turn if it locks up suddenly, especially in the wet? Thanks in advance for any input, Howie
I have a centrifugal unit in my Jeep Scrambler. Its effective, but it has a noticeable effect in curves. My sister refuses to drive it because of the soft locker. Their biggest advantage is that they can be installed quickly and easily. No change to the carrier is necessary. As a wheel loses traction and the wheel begins to spin much faster relative to the other, the centrifugal force locks the two halves together. It clunks together and often causes an audible tire screech. The clutches in a limited slip differential are much smoother and less likely to scare the driver, but in some ways that makes them less effective than a soft locker.
A hard locker is much more expensive and harder to install. The one I want to buy for my 401 5 speed SX4 is electric. Its a limited slip until you push the button and then the axles are fully locked together. My Rubicon has this option front and rear and I absolutely love them. Most of us would never install one since they're worth more than the average Eagle. I think a soft locker costs about 300 dollars and a hard locker 1200 to 2000 dollars. A limited slip differential is expensive unless you buy a whole axle with a factory unit already installed.
[/quote]
Look at my reply on this thread it gives the proper name for the different traction aiding differentials. It is post #21. If you are talking about a lunch box locker, they are not centrifugal. The only centrifugal locker I know about is the Gov-loc used on older Chevys.
Quote from: PR1AWRet on June 04, 2012, 12:09:25 PM
Look at my reply on this thread it gives the proper name for the different traction aiding differentials. It is post #21. If you are talking about a lunch box locker, they are not centrifugal. The only centrifugal locker I know about is the Gov-loc used on older Chevys.
Thank you very much, the primer in what is what helped indeed. I was sort of thinking this is what was meant the the centrifugal unit indeed being the Gov-Loc. I will look into the many options seeing there is much available for the AMC15/Dana35's.
Quote from: Einsteins Eagle on June 04, 2012, 11:22:11 AM
I'm sure I could install it myself, reading you keep the same carrier and do not have to disturb crown/pinion during the project. How noticeable is the unit on the road, does the device make the Scrambler jump sideways badly in a turn if it locks up suddenly, especially in the wet? Thanks in advance for any input, Howie
I disagree in the proper names listed earlier in the thread and I especially disagree with the comment that the only "centrifugal" unit that exists is one obscure type. Forums are full of such silly arguments. That's as ridiculous as objecting to calling an AMC Eagle "All wheel drive" just because the factory didn't use the term (Subaru coined the term in 1984, long after the 1980 Eagle's pioneered the concept). Another favorite of mine was the recent arguement about the definition of "coupe." Who cares about the names, we just want to discuss the options you have to spend money on.
I personally have just two categories for full time automatic units. I look at the options as "Centrifugal" or "Clutch type Limited Slip" to mean it either needs a new carrier or it doesn't. In other words the installation is either expensive and hard or cheap and easy. Either I would install it in a car my grandmother owns or I wouldn't.
If you punch in "dana 35 locker" as a search term into ebay you'll see a huge list of lockers that retail between $270 and $350 new under such names as lunchbox locker, soft locker, Powertrax, Spartan, Lock Right, etcetra. Those are great because they are very cheap and easy to install. You can install them into your existing carrier in almost no time flat with no special tools or skills. I call those "centrifugal" lockers because they consist of two halves seperated by springs that have teeth built into them. As the wheels spin relative to each other the springs keeping the two halves and their teeth apart get pushed in through centrifugal force. When the teeth come into contact they crunch together with a dramatic jerk. If you continue to accelerate the two halves remain locked together. You need to back off on the gas pedal before they release. When they release it can be just as dramatic as when they lock up if you're driving aggressively.
That is what my Scrambler currently has. It sucks. The tires chirp around tight curves and the sudden jerk as it engaged frightened my sister. I'm used to it and I don't care much. I certainly would not justify a nicer locker in the cheap Dana 20 axle I still have in that truck. It works fine and I generally like it. It does not have a dramatic impact on driving quality if you take your foot of the gas during the curve. The heavy jerk really only happens when you try to accelerate through the curve aggressively.
Do you drive the car to work every day and on the beach several times a year? Install one. Does your trophy wife and your grandmother drive the car as often as you do? Don't install one and invest that $300 toward a better, smoother unit.
Most people call factory limited slip differentials "Positraction" just like they call tissues "Kleenex." That broad category of clutch style limited slips are very nice and very smooth working. They are much more expensive and they generally wear out in ways that a lunchbox locker never would. You must replace the whole carrier to install one. There are plenty of options for all budgets.
Here's some stuff I found in a quick ebay search. I disregarded all the lunchbox lockers because I personally will never install another one. I loan my cars out to all my family and friends and I will always choose to pay a little more for a quality driving experience that I can be proud of.
I also disregarded all the typical offroad lockers that are designed to be an open differential on pavement and then fully lock while offroad. Those don't help improve traction when you drive to work.
Here are some options I found:
-Detroic "Truetrac" advertises the smooth operation of a true OEM limited slip without the need to replace the clutch packs or use the oil additives. They seem like the foremost choice. There was one vendor offering several new units for $400 and several people selling them for about $550.
-"Trac-Lok" is the Dana Spicer term for the OEM style limited slip. It has a replaceable clutch pack and requires additive to the differential fluid. It works very smoothly and might be available used. There was an auction there with a buy it now of $289, but generally these are more expensive closer to $400 brand new.
-"Powr-Lok" is OEM style with a replaceable clutch pack.
-"Yukon Positraction" seemed to be a style similar to the OEM Chevy version of the "Trac-Lok."
-"Auburn Gear Positraction" was an interesting option. It was relatively cheap at $285 and it looked like a normal lunchbox locker in the diagram. The difference was that it was advertised to have cone clutches and it seemed to require the replacement of the whole carrier. It seemed to be vastly better than a typical lunchbox locker but not quite as nice as a usual limited slip. That might be a great option for some people.
-I didn't find it but Detroit does make an Electric locker very similar to the older Rubicon electic lockers. Those are awesome. They cost about $1200. It acts as a very smooth limited slip in normal operations but it can be fully locked with a button in the cab. That's the ideal locker for someone with a big budget and high standards. I plan on using one in my nicest Eagle. I already have the factory version in my 2006 Jeep Rubicon and I love it.
FYI the older AMC designed 2004-2006 Jeep Rubicons had electric lockers that acted as limited slips until locked, while the newer all Chrysler Jeep JK Rubicons do not act as limited slips. They only electonically lock.
Quote from: captspillane on June 05, 2012, 12:18:33 AM
-I didn't find it but Detroit does make an Electric locker very similar to the older Rubicon electic lockers. Those are awesome. They cost about $1200. It acts as a very smooth limited slip in normal operations but it can be fully locked with a button in the cab. That's the ideal locker for someone with a big budget and high standards. I plan on using one in my nicest Eagle. I already have the factory version in my 2006 Jeep Rubicon and I love it.
FYI the older AMC designed 2004-2006 Jeep Rubicons had electric lockers that acted as limited slips until locked, while the newer all Chrysler Jeep JK Rubicons do not act as limited slips. They only electronically lock.
Eaton E-Locker. Detroit is a sub division of Eaton.
I agree on the newer Rubicons, But I said a variation meaning not all.
If we ALL use the proper nomenclature, we will ALL be on the same page.
That is all I will post on this subject here. It's not a mine is bigger than yours contest.
ARB did the Rubicon lockers and onboard air (they are close to me here. I wish I'd applied to work there instead of NAPA 10 years ago)