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Author Topic: Is it true no Eagles were factory twingrip or other posi?  (Read 13486 times)

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Offline carnuck

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Is it true no Eagles were factory twingrip or other posi?
« on: September 22, 2011, 11:52:09 PM »
Had someone on another forum state this as a certainty. I've never seen one myself. Anyone see a FACTORY installed one?
AMC/Jeep gauges are for amusement only. Any correlation between them and reality is purely coincidental!

Offline captspillane

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #1 on: September 23, 2011, 01:22:14 PM »
It is a fact that AMC did not offer twin grip as an option for AMC Eagles. The factory considered the front axle more traction than you could need.

The twin grip is also very rare on Spirits and Concords, although the option from the factory did exist.

I am putting a factory posi from a 2wd commanche into my Eagle when I upgrade the axle to a Dana44. It will have a drastic improvement in traction and will not affect the vehicle's handling. A "soft locker" is much more aggressive than the limited slip posi, those will have a noticeable jerk to the rear as you make tight corners. For an Eagle set up for rock crawling it would make sense to put a soft locker in the front axle, but a disconnect must be retained for street driving. A soft locker in the front will make a huge impact on steering and road driving.

The viscous coupling on the Eagle transfer case wears out and is supposed to be routinely replaced. None of us do that. Once it wears out your transfer case is an open differential. If you put the NP231 from a Cherokee in, you'd have low range and transfer case outputs rigidly connected. Thats the definition of the term "Command-trac." There are also alot of Cherokees with "Select-trac," which has an open differential or viscous coupling in the transfer case. The impact of lockers in the front and rear will be more noticeable with a solid transfer case.

All Jeep transfer cases, regardless if they have a viscous coupling or not, have directly connected outputs while in low range.

-Dave Spillane-
Currently Inspected and Insured as of Jan 2013:
-1985 Eagle Station Wagon 258 T5 Stickshift
-1980 Eagle Station Wagon 258 Auto Fuel-injected with GM TBI

Minor Repairs Underway:
-1982 Eagle SX4 258 T5
-1981 Kammback 2.5L Iron Duke T5

Restoration Efforts Near Completion:
-1982 SX4- 401 NV3550
-1983 SX4- 4.5 MPI NSG370 (6 Speed)

Restoration Efforts Underway:
-1985 SW- 4.0 MPI AX15
-1982 SX4- 4.0 AW4
-1981 SX4- SD33T NV4500 (Turbodiesel 5 speed)

Future Rescue Efforts- '85 Maroon SW, '87 Limited SW, '84 Limited SW, '87 4 door Sedan, '81 2 door Sedan, '88 White SW, '77 4 door Hornet, '74 2 door Hornet, '79 Spirit AMX, '81 Kammback.

RIP- Red '81 SX4, '84 4dr Sedan, '84 SW, '81 SW, '80 Spirit, '83 SW, '83 4dr Sedan

Offline Hawk258

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #2 on: October 22, 2011, 01:09:56 AM »
Now there is an interesting idea, The newer jeeps have an e-locker for both front and rear. That could be fun for some of the SAS that people have done.


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 captspillane

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #3 on: October 22, 2011, 01:46:29 AM »
My 2006 Rubicon has the E lockers. They are awesome. The rear is designed to be a very smooth limited slip when its not locked. They also make an aftermarket version that is readily available for the Cherokee Dana 44s going into my Eagles. Those are also limited slip when not locked I believe. At some point I will also try to shoe-horn a cable, pneumatic, or electric locker into the Eagle front axle casting. It may be possible with some machine work.

I will never ruin the Eagle driving experience by putting a solid front axle under any Eagle I own, so its worth working with the original front axle. I also cherish the low center of gravity, so the only lift I will consider comes from larger tires installed with fender modifications only.

In the future I want to make my own front axle that has a better differential with E locker and still connects to the factory half shafts. It has been suggested on this site that a Ford Ranger front axle has the same spline count and diameter as an Eagle front axle. We could have our front axle shafts installed on it if custom axle tubes were made. Obviously any other front differential would not have the bolt bosses in the casting, but anyone who can shorten and modify a differential to the proper width can also make an adaptor to hang the differential from.
Currently Inspected and Insured as of Jan 2013:
-1985 Eagle Station Wagon 258 T5 Stickshift
-1980 Eagle Station Wagon 258 Auto Fuel-injected with GM TBI

Minor Repairs Underway:
-1982 Eagle SX4 258 T5
-1981 Kammback 2.5L Iron Duke T5

Restoration Efforts Near Completion:
-1982 SX4- 401 NV3550
-1983 SX4- 4.5 MPI NSG370 (6 Speed)

Restoration Efforts Underway:
-1985 SW- 4.0 MPI AX15
-1982 SX4- 4.0 AW4
-1981 SX4- SD33T NV4500 (Turbodiesel 5 speed)

Future Rescue Efforts- '85 Maroon SW, '87 Limited SW, '84 Limited SW, '87 4 door Sedan, '81 2 door Sedan, '88 White SW, '77 4 door Hornet, '74 2 door Hornet, '79 Spirit AMX, '81 Kammback.

RIP- Red '81 SX4, '84 4dr Sedan, '84 SW, '81 SW, '80 Spirit, '83 SW, '83 4dr Sedan

Offline JayRamb

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #4 on: October 22, 2011, 04:16:40 AM »
All I know is that both of my Eagles act as if they have Posi/Twin Grip if I want to spin out the back tires, both back tires spin out equally.
Jayson H.
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1967 Rambler Rebel 4 Door 290 V8 (original family car) Marina Aqua 142K miles
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Offline captspillane

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #5 on: October 22, 2011, 04:52:46 AM »
I have thrown rooster tails from all four tires on my Eagle many times. Thats with an open differential in the transfer case and two open differentials in the front and rear. The differentials naturally split the torque even without limited slip. The only time I can really tell a difference is when one wheel is totally up in the air. If you put a jack under one tire on your Eagle so that its not touching the ground, it will spin away while the other sits still. If both tires are held up off the ground, they will happily spin together. Honestly limited slip is overrated, since an Eagle that is stuck in mud would be more likely to get out with a low range than a limited slip. Low range lets you put slow steady pressure on the wheels without reving the engine up. Thats usually enough to get all the wheels to play together.

Its true that the factory never put a limited slip in an Eagle. Its also true that my 2006 Rubicon with its wide 33x12.5 tires cannot keep up with my Eagle even with all four wheels fully locked. It got stuck with all four wheels spinning in 8 inches of snow. My Eagle with all open differentials did not get stuck in the same storm because of the skinny tires. It helps that the independent front suspension and low center of gravity lets me go three or four times faster than the Jeep can. In some ways AMC knew what they were doing when they concluded that Eagles didn't need them. Of course we still want them regardless.
Currently Inspected and Insured as of Jan 2013:
-1985 Eagle Station Wagon 258 T5 Stickshift
-1980 Eagle Station Wagon 258 Auto Fuel-injected with GM TBI

Minor Repairs Underway:
-1982 Eagle SX4 258 T5
-1981 Kammback 2.5L Iron Duke T5

Restoration Efforts Near Completion:
-1982 SX4- 401 NV3550
-1983 SX4- 4.5 MPI NSG370 (6 Speed)

Restoration Efforts Underway:
-1985 SW- 4.0 MPI AX15
-1982 SX4- 4.0 AW4
-1981 SX4- SD33T NV4500 (Turbodiesel 5 speed)

Future Rescue Efforts- '85 Maroon SW, '87 Limited SW, '84 Limited SW, '87 4 door Sedan, '81 2 door Sedan, '88 White SW, '77 4 door Hornet, '74 2 door Hornet, '79 Spirit AMX, '81 Kammback.

RIP- Red '81 SX4, '84 4dr Sedan, '84 SW, '81 SW, '80 Spirit, '83 SW, '83 4dr Sedan

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #6 on: October 22, 2011, 08:36:39 AM »
I am curious if the inards and axles from a limited slip would fit inside the same year houseing of a non limited slip.
I have a non from a 68 amx, and the guts to a limited from a 68 amx...... any thoughts?

Offline captspillane

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #7 on: October 22, 2011, 12:50:11 PM »
There may be exceptions, but I do not know of any axle that has a different casing for its limited slip. The limited slip components are all contained in the carrier assembly, which can be removed independently of the axle shafts and case casting. The carrier is easy to remove to facilitate changing out the gear ratio ring. You should have no problem.
Currently Inspected and Insured as of Jan 2013:
-1985 Eagle Station Wagon 258 T5 Stickshift
-1980 Eagle Station Wagon 258 Auto Fuel-injected with GM TBI

Minor Repairs Underway:
-1982 Eagle SX4 258 T5
-1981 Kammback 2.5L Iron Duke T5

Restoration Efforts Near Completion:
-1982 SX4- 401 NV3550
-1983 SX4- 4.5 MPI NSG370 (6 Speed)

Restoration Efforts Underway:
-1985 SW- 4.0 MPI AX15
-1982 SX4- 4.0 AW4
-1981 SX4- SD33T NV4500 (Turbodiesel 5 speed)

Future Rescue Efforts- '85 Maroon SW, '87 Limited SW, '84 Limited SW, '87 4 door Sedan, '81 2 door Sedan, '88 White SW, '77 4 door Hornet, '74 2 door Hornet, '79 Spirit AMX, '81 Kammback.

RIP- Red '81 SX4, '84 4dr Sedan, '84 SW, '81 SW, '80 Spirit, '83 SW, '83 4dr Sedan

Offline wagonmaster

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #8 on: October 22, 2011, 05:41:32 PM »
ive bean dreaming about this very thing for months. my thought was to swap in a ford 8.8 from an explorer with limited slip and disc brakes or upgrade a non lsd with an air locker. of course i would need matching ratios in the front and i havent done all my research on that yet.

Offline Sunny

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #9 on: October 23, 2011, 10:07:21 AM »
I knew I'd read something official somewhere! ;D Page 2F-44 of my '83 TSM:

"A Twin-Grip limited-slip differential is available as an option in all AMC automobiles except Eagle models."

I'm surprised they didn't offer it.
A limited slip differential seems like it would be a great addition to an Eagle. It's one of the first options I ordered on my truck when I got it.

I know my grandfathers Javelin had a limited slip, but I'm not sure if it was factory or not.

68AMXGOPAC

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #10 on: October 23, 2011, 12:49:02 PM »
I would think it was factory , it was offered in many models as an option with the v8's.

Offline Sunny

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #11 on: October 23, 2011, 01:15:53 PM »
I would think it was factory , it was offered in many models as an option with the v8's.
'

I was younger when he had it, so it's one of those things I never asked. I wish the car was still around, as it would have gone to me and I could have restored it.

Offline mick

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #12 on: October 23, 2011, 11:51:44 PM »
I will never ruin the Eagle driving experience by putting a solid front axle under any Eagle I own, so its worth working with the original front axle.

I used to say the same thing. 
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Offline BenM

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #13 on: October 24, 2011, 11:37:25 AM »
I've never run any kind of limited slip, but I've considered the Torsen-type front units in the past. The thinking being that it would reduce overstear in slippery conditions like snow.
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Offline Sunny

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Re: Is it true no Eagles were factory twingrip or other posi?
« Reply #14 on: October 24, 2011, 12:54:47 PM »
I've never run any kind of limited slip, but I've considered the Torsen-type front units in the past. The thinking being that it would reduce overstear in slippery conditions like snow.

There is a pretty noticeable difference between an open and limited slip differential in the snow.
The only thing is, if you don't know how to drive, you'll just end up sliding sideways. Lockers are significantly worse for that.

Anything is an upgrade over an open differential though.

 

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