AMC 20

[MocKKnighT]

I'm just inquiring about the AMC 20, What is peoples opnion on this axle? Can it handle 35's or would a swap be in order? Anything about this axle will help, since i'm not very familiar w/ it.

[AMC258]

It's comparable to a Dana 44, from what I've read on here, 35s are the most you'd want to put on it, and you'll have to regear.

[Robber80]

35s are fine. it all depends on how hard you wheel though. cause i can baby my 38s for some little stuff and of course they can hold up. but all it takes is an eager right foot to blow it up in lowrange.

[scotty]

its just alittle better than a 44,IMO dues to a slightly larger pinion(1.6" diameter vs 1.3 for the 44)

the m20 gets a bad rap from the version used in CJd wich was prone to spinning tubes an spinning the hub on the 2 piece axle.

fear not,the FSJ m20 has a thicker housing and 1 piece axles from the factory,so neither is really an issue.

wether it will hold up to 35s depends largely on your right foot ;) if you wheel conservatively,it will be fine,if you have a "make it or brake it" approach an upgrade may be in order.

i ran 38s on an m20 for a couple of years,with the last year welded,and it held up well for me. but i ran an auto tranny back then,and was not nearly as hard on it as i am now.

[J10Mike]

i have the amc20 and i'm running 35s. but with 3.31 gears, i'll be re-gearing in the near future. it does alright for now though.

[Rick78J10]

I have an AMC20 from a waggy that I use in an '85 Cj-7 with a 258 and auto, with a 4:1 lowrange and 4.56 gears and detroit locker. It is a spring over jeep that wwe rockcrawl and trail ride with. Have been using it for 3 years without any problems. Oh and we have been running 35" tires. Just went to 37" and working fine in the rocks at Paragon

[Joe Guilbeau]

When I bought my '83 Cherokee the AMC-20 housings were bent...both sides.

I think the previous owner saw one too many episodes of "Dukes of Hazard"...

Cracked the frame above the rear axle, broke the transfer case, one motor mount, cracked the plastic gas tank, all in all a pretty good job.

I caught him the day before he was going to trade it in to a dealership...so I offered him in cash what the dealership was willing to give him in trade in value...

After the deal was done, I asked him what he was going to buy, now that he had some additional cash to dicker with...he proudly proclaimed:

"I am going to buy a REAL 4x4; a Ford Ranger!"

I don't really know what he did to bend both housing for the AMC-20, but I had a pretty hard time finding a replacement for the Wide-Trac and instead went with a Dana 60 out of a 78 J-20 that Jim's Offroad rebuilt.

[BigDC]

Running a 20 with 35's and 4.56 gearing..the thing does just fine...bought the Waggy from a guy in my local club who said he never had any problems with it and it's been throught the 7 trails at Paragon with no other damage to show other than body damage ;) He certainly built the thing right....the 20 is a good piece of work from AMC in my opinion, certainly better than the 35c on my '00 TJ ;) , and I was running 33's on that with 4.10 gearing

DC.

[sheffield]

has anyone built a truss for the 20, just looking for ideas 'cause I hear they have weak housings and it would be some cheap insurance.

Drew

[robselina]

Originally posted by sheffield:
has anyone built a truss for the 20, just looking for ideas 'cause I hear they have weak housings and it would be some cheap insurance.

Drewthat's the CJ version, not the SJ M20 (or M23 depending on who you talk to). Wheel it as is and if you bend it up go for more beef. It's good for what it is, but I wouldn't sink any money or effort into it...

[youngjeeper]

your runnin it in a YJ too, so youll have alot less weight then us fullsizer's

[Joe Dirt]

your asking about a full-size m20, it's not the same as the cj m20 that commonly bend tubes around the housing. the tubes are a bit thicker in the sj version, and the axles are one piece, not 2 piece w/ an optional and expensive one piece conversion

[scotty]

Originally posted by sheffield:
has anyone built a truss for the 20, just looking for ideas 'cause I hear they have weak housings and it would be some cheap insurance.

Drewlike the guys said,the FSJ version is not any more likely to bend tubes than the a FSJ d44,its much stouter than the CJ m20

however,its a good idea IMO to truss any axle,no matter what it is(60,14 bolt,44,whatever) a slightly tweaked or bent housing could lead to alot of reoccuring little prollems like bearing/seal failures,or even axleshaft/spider gear breakage in more severe cases.

if you can weld you can make a decent truss with just a few $$ worth oif scrap metal smile.gif

[sheffield]

Originally posted by scotty:
</font><blockquote>quote:</font><hr />Originally posted by sheffield:
has anyone built a truss for the 20, just looking for ideas 'cause I hear they have weak housings and it would be some cheap insurance.

Drewlike the guys said,the FSJ version is not any more likely to bend tubes than the a FSJ d44,its much stouter than the CJ m20

however,its a good idea IMO to truss any axle,no matter what it is(60,14 bolt,44,whatever) a slightly tweaked or bent housing could lead to alot of reoccuring little prollems like bearing/seal failures,or even axleshaft/spider gear breakage in more severe cases.

if you can weld you can make a decent truss with just a few $$ worth oif scrap metal smile.gif </font>[/QUOTE]Thats what I figured, I have access to a full shop and a lot of scrap. Also, I have a a heavy right foot and enjoy air time. So I figured it wouldn't hurt anything and would be an excuse to weld some stuff.

Drew

[scotty]

now youre talkin! having only had a welder for a couple years now, ill jump at any opportunity to weld/fab stuff :D