AMC 20

Rogue Racer

I am wanting to build up a stout AMC 20. Is there any particular housing that is to be preferred for strength? I currently have a housing from a '77 Matador and one from a '74 CJ. They both look to be about the same as far as casting thickness and construction. Maybe they are all about the same, but I would like to hear from some people with a lot more experience with them. Please bypass comments about using a Dana 60 or some other rear; I want to know about the AMC 20. Thanks!

dbesade

There is a good article about the 20 here.

As far as making it a better axle, I would put a pair of one piece axles in there to get rid of the 2 piece they came with (in the CJ axle, not sure about the other one). I would also stitch weld the tube to the pumpkin to prevent the tube from spinning on you (read around the forum, that happened to someone not to long ago here).

The other thing I would do is build a truss to prevent the tube from flexing. Do that and I think you would have a pretty damn good '20.

(here is a picture of an AMC20 with a truss)

Hope this helps ya out and gives you the answers your looking for.

-Dave

fuzz401

a 74 cj should be a dana 44 with flange axel's thats what I run in my 789 cj

tufcj

One more thing is to check the spring mount pads. They aren't that strong to start with and are prone to rust. If they're not rusty, add a strap over the top of the axle, welded to the tube and each end of the pad. If they're rusty, just replace them with beefier units. I've seen them buckle and allow the axle to twist when used with big tires and lockers. Bob tufcj

runnamuck

second on desade and tufcj

Rogue Racer

Thanks!! I appreciate all the info! This all corresponds to what I had planned up to do. What I am really looking for is an experienced opinion whether some particular housing is stronger than others. So far I have steel bearing caps, a spool, one piece axles, some 1 1/4" CM tubing to build a brace, a vertical mill, a TIG welder, a power cut-off saw, and a jig to correct the housing for straightness. I'm ready to build a stout one! I just want to make sure I start with the strongest housing made. Any suggestions???

dbesade

Rogue Racer wrote
Thanks!! I appreciate all the info! This all corresponds to what I had planned up to do. What I am really looking for is an experienced opinion whether some particular housing is stronger than others. So far I have steel bearing caps, a spool, one piece axles, some 1 1/4" CM tubing to build a brace, a vertical mill, a TIG welder, a power cut-off saw, and a jig to correct the housing for straightness. I'm ready to build a stout one! I just want to make sure I start with the strongest housing made. Any suggestions???

As far as I know the housings were all pretty much the same. I would personally do the one you have from the CJ but thats me. The only AMC 20's that may be a bit different are the ones from the 1980's + Wagoneers. They may have a bit heavier tubing and the like on them and they are 6 Lug.

-Dave

Rogue Racer

dbsade - Thanks! I was planning on using the CJ housing simply because it doesn't have the ears on it for the control arms - it will make a cleaner looking piece.

jeepsr4ever

I believe the FSJ version has thicker tubes which may or may not interest you.

zero cool

jeepsr4ever wrote
I believe the FSJ version has thicker tubes which may or may not interest you.

The axle in the 1980-1986 full size wagoneers and J-10's (not J20's) as well as the 80-83 Cherokee will have the AMC 23. It's basically an AMC 20 with thicker tubes and one piece, 6 lug axles.

If you're going to go to all the trouble of cutting and sizing the housings anyway, that's the platform to start with.

The narrow track Wagoneer/Cherokee is just an inch or two wider than the wide track CJ. The wide track Cherokee is about 6-8 inches wider. The J-10 uses an axle about an inch or two wider than that.

The J-20 uses a Dana 60.