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Author Topic: What are my options for the diffs  (Read 5661 times)

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Offline Boonsie

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What are my options for the diffs
« on: January 04, 2012, 02:43:32 AM »
First off I have a 4.0 stroked and bored to a 4.6 c/w AX-15 and NP242. So this thing will have some grunt. So I'm looking at the diffs now. I believe I have the Dana 30 in the front and the 35 in the rear? Not sure what the ratios are, it's an 82 wagon sold in canada, came with the 3sp auto and whatever t-case that was 2h and 4h i believe. So I think I'm running 3.07??? Anyways I know it's an open diff and that doesn't sit well with me. I want to at least out a trac-lok in the rear, but I know there are better options out there, especially for the added power that'll be going through there.

Can someone please let me know what to look into, be it a ford 8.8, dana 44 or keep the 35??? My big question is, if I swap the rear with a different diff, what do I do about the front. Match ratios, swap that as well?

So what are my best options, welding and turning wrenches doesn't bother me.

Offline Hawk258

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Re: What are my options for the diffs
« Reply #1 on: January 04, 2012, 05:07:11 AM »
To be honest you are limited on what ratios you have at your disposal, I don't have the exact list, but the eaglepaedia does I believe, I would suggest starting there. HOWEVER there are a few options that haven't been tried but speculated at, Ford Explorer and Dodge Dakota/Durango and I believe Chevy has one a 4wd that has IFS front and solid rear axles the only thing you have to contend with is mounting options and yokes/universal joins and shafts, it is a bit time consuming, HOWEVER it is an option if money is no object as I have found an outfit that makes custom CV shafts for most any application, the link is in "New member has crazy idea" a set will cost you about $2500+, BUT the shafts are guaranteed for life, and the CV joint can be replaced/repaired for about $80 but this is the "Best" option for swapping that I have found at this point other than doing a Solid axle swap on the front. But this is just my opinion.


Ingenuity through stupidity, Do something stupid and through Ingenuity you will find a way out of it.

1981 AMC Eagle (Currently in need of a bellhousing OR the project to iron it's self out)

1982 Subaru Brat White (Daily driver inheritence from mom ((Don't worry mom I won't break it))
other prior vehicles include:
1985 Dodge (OMNI) charger
1979 Dodge Ram Charger
1985 Dodge Diplomate
1982 Subaru wagon
1980 AMC Spirit
1982 AMC Eagle wagon (Was going to be parts car)

Offline txjeeptx

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Re: What are my options for the diffs
« Reply #2 on: January 04, 2012, 08:28:52 AM »
Get rid of the factory Model 15(predecessor of the Jeep Dana 35). That is what you have in an Eagle with a factory axle housing, and it has two-piece axle shafts(hub flange is keyed to shaft and held on with a large nut).

The front axle in an Eagle is kinda difficult to regear. There are different carriers for different ratios(similar to Jeep), but if you have a 2.35 gear ratio(common in Eagles that came with auto trans), ther is NO aftermarket or factory gear that will fit on the 2.35 differential carrier, other than the 2.35s.

What tire size will you be running? That's relatively important. Also, what are your build goals(like economy or offroad or maximum acceleration/fun)? Mine were the latter(autocross/subaru killer), and I chose 3.54/3.55 gears for my car. In order to do 3.54 front gears, I bought an entire front axle housing from a 4-cylinder Eagle, which came with 3.54 gears. The Eagle front axle housing is a D30, but it is not the same carrier as Jeeps, so I ran into an issue of not being able to install a traction device in it. I left it open, which is fine for the street, which is where my car is staying.

In the rear, since my car is staying on the street, and it is going to be running slightly smaller than stock(but much much wider) tires, I deceided that the later Jeep D35 would be fine for the street. XJ Cherokee rear axles( D35, D44, & Chrysler 8.25) are near bolt in to Eagles(not sure about the SX/4), but mine actually came out of a ZJ, so it has factory disk brakes with a parking brake setup, installed a Detroit True-trac full case Torsen(geared) limited slip. It is a C-clip axle, but I doubt I'll ever manage to pound on it hard enough to break a shaft. I cut off all the control arm brackets, and installed the leaf spring perches and shock mounts(same as XJ, available from Jeep fab shops like Rubicon Express or Rusty's Offroad). Still have to finish weld the perches, setting the differetnial pinion angle, and get a new rear driveshaft fabbed up. Also need to finish weld my AX-15/242 crossmember. Might be swapping in a ZJ 249 case, since I want the viscous coupler(a limited slip) instead of the 242's open diff. My reason for staying with the puny D35 is its light weight. The D44, 8.8, and Chrysler 8.25 are much heavier.
'82 Eagle SX/4 "Golden Eagle", '89 YJ 2.5L '93 MPI-converted rock-crawler, '79 Jeep Cherokee Golden Eagle "FSJ", 'o7 F150 Supercrew FX/4 daily driver

Offline carnuck

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Re: What are my options for the diffs
« Reply #3 on: January 06, 2012, 01:10:10 PM »
I have a Chrysler 8.25 with 3.08 ratio to go into my wagon. (don't know what the original ratios are yet but I have a 3.08 non-vacuum front to match) My old wagon with a stroker in it had 2.37 gears and I killed several 998 autos trying to tow a big homemade trailer (made from a '91 IH bus) with it but I had no power problems. A 727 would've cured the trans issue, but I had a rear axle snap after getting hit on the driver's side and discovered major frame rot when I went to swap the diff (trans was dead again too)
   I ended up putting the 282 into an '83 Cherokee with 999 auto (it had been rebuilt with a billet converter before I bought the truck) and since it could handle the loads at the time, I sent that Eagle to the scrap bin and I've been looking for a good one till I found my current one (I even started turning my '82 Spirit into an SX4)
AMC/Jeep gauges are for amusement only. Any correlation between them and reality is purely coincidental!

 

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