AMC 20 Rearend

Inisadow · Nov 13, 2003

I just picked up an 81 SJ and was a little disappointed to find it had the AMC 20 rearend and not the Dana 44. Exactly how much weaker are they and where?

I've heard that it's the axle housing and tubes that are the weak point, and not the carrier assembly or the axel shafts. The last dana 44 I had was spooled and I never had any problems at all with it, and I'd like to do the same to this axle. Besides the obvious, would there be any problems spooling an AMC 20? No big tires or anything either, just some 30x9.5's or so.

LRRH · Nov 13, 2003

well...the SJ ones aren't so bad. Though...I would rather have a Dana44. The most common problems were in the CJ one's cause they were two piece instead of one piece.

As long as you do proper maintenance you shouldn't have any problems running 30s or 31s.

JnJ · Nov 13, 2003

That axle is a close camparision to the 44. With tires the size your talking, you'll be fine.

Eagle · Nov 14, 2003

I had a '78 Cherokee with a snow plow for several years. So did my brother. IIRC we were on AMC 20s. We both ran 31" tires with no problems.

mark268 · Nov 14, 2003

Those amc 20's are not bad.

CJ 20's have 2 piece axles which are keyed. They tend to twist free under hard wheeling. Easy fix, one piece axle shafts. I welded my housing tubes, one piece axles, locked and braced. As strong or stronger than a stock 44.

You will be fine with the sj amc20.

LRRH · Nov 14, 2003

IIRC we were on AMC 20s

Nope...the AMC20 was only offered from 80 until 85 I believe....at least on Sjs.

mark268 · Nov 14, 2003

Quote from Jeep Tech

" The Wagoneer and full size Cherokee also used a narrow and wide track version of the AMC 20. Both SJ versions used once piece shafts and 6 on 5.5" wheel bolt pattern. Since the length and bolt pattern is different from the CJ version, the SJ shafts are not compatible without resplining and redrilling. I've never heard of anyone going to the trouble "

80-91 SJ's

LRRH · Nov 14, 2003

http://www.ifsja.org/tech/figures/db.shtml#rear

my 86 has a Dana44 stock read. they stopped using them in SJs all after 86 have Dana 44s.

JnJ · Nov 14, 2003

mark268 said:
Quote from Jeep Tech

" The Wagoneer and full size Cherokee also used a narrow and wide track version of the AMC 20. Both SJ versions used once piece shafts and 6 on 5.5" wheel bolt pattern. Since the length and bolt pattern is different from the CJ version, the SJ shafts are not compatible without resplining and redrilling. I've never heard of anyone going to the trouble "

80-91 SJ's

Not exactly correct. THe Wagoneer used narrow track, never a wide track. Wide Tracks were only on the Cherokees.

Eagle · Nov 15, 2003

JnJ said:
Not exactly correct. THe Wagoneer used narrow track, never a wide track. Wide Tracks were only on the Cherokees.

To be even more specific, the wide axle (which was the same as the PU trucks) was used only on 2-door Cherokees with the "Wide Wheel" option. My brother had the option. It came with white "wagon wheels" and 31" tires. Mine was the same year and a Cherokee, but a 4-door. Mine came with alloy rims and 235/75R15 tires.

mark268 · Nov 15, 2003

okay, that may be true I don't know and I am not an expert. The info I provided came directly from Jeep Tech www.Jeeptech.com
Which is a very good resource, but no one is perfect.
What I am sure about is I am not going to argue this out.....I am definatly not confident in the answer. Hopefully he will find the info he needs. Just trying to help and BTT

AMC 20 Rearend

Inisadow

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LRRH

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JnJ

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Eagle

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mark268

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LRRH

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mark268

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Eagle

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mark268

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