axle swaps and the amc 20

[1986cj7]

It seems like everyone wants a differant axle besides the AMC20 . But from what I've read and heard is that the AMC20 can be made strong by welding the tubes to the diff. and putting support brackets form the tubes to the frame. Also up gradeing the axles from 2 piece to 1 piece. Now I've done the one piece upgrade, but not the welding of tubes and brackets. Is this info correct or just someones opinion. I also have the Dana 30 up front and have up graded the axles to 4340 chromoly. Are there any other ways to strengthen the Dana 30 or is it good as it is now. Also the yokes are of the strap type not the u bolt type which is better. Seem to me the u bolt would be stronger but not sure? Any opinions or advice is apperceated. Thanks

 

[IOPort51]

I think you have all the facts straight. I think it's a question of crunching the numbers and comparing what the mods to the 20 will cost over the purchase of another axle, the Dana 44 as an example.

It seems like everyone wants a differant axle besides the AMC20 . But from what I've read and heard is that the AMC20 can be made strong by welding the tubes to the diff. and putting support brackets form the tubes to the frame. Also up gradeing the axles from 2 piece to 1 piece. Now I've done the one piece upgrade, but not the welding of tubes and brackets. Is this info correct or just someones opinion. I also have the Dana 30 up front and have up graded the axles to 4340 chromoly. Are there any other ways to strengthen the Dana 30 or is it good as it is now. Also the yokes are of the strap type not the u bolt type which is better. Seem to me the u bolt would be stronger but not sure? Any opinions or advice is apperceated. Thanks

 

[CJim7]

There's not a lot more you can do with the Dana 30 front. The problem is everytime you upgrade a component, something else becomes the weak point. A lot of people upgrade the hubs to a six bolt style, but that's where I like to keep my weak link. If you upgrade the hubs and shafts, you are left with a ring and pinion that becomes the weak spot...that's the last part of the axle you want to break.

I believe you are refering to a truss when you mention bracketry on the rear corp 20. The 1-piece upgrade is a good start. welding the tubes is not completely neccesary unless you are running a lot of horspower/torque and larger tires.

 

[1986cj7]

No big horsepower just stock AMC 258 i6 / 4.2l . But do have 33" and don't plan on going any larger. Yes you are right truss is what I was thinking of just didn't know term. So if a motor swap is in far future trussing and welding AMC20 is what I'll need to do. In your info you say you have a t18a hooked up to a Dana 300 twin stick this is some thing I'm looking at doing to mine. Does the T-18 and t18a need an adapter to hook up to the Dana 300 ? Thanks for the info.

 

[Old Dog]

I'm sill running a 20 with one piece axles, not welded or trussed, it also has a detroit locker and 33's. I have beat it pretty good over the years.
My front 30 also has the alloy axles with the bigger u-joints.
with 4:10's and a 300 hp 350 chevy with a TH350 all has been good so far.

 

[Purple77CJ7]

I run both the Dana 30 and the AMC20 with 33's. I look at it, this is what I have so run it till it dies. I have upgraded axles in both and arb lockers, welded tubes and I made trusses. I worked em' pretty good and they still survive. I have considered running 35's in the future and think they will be fine with some judicious throttle peddle. That is the key with any setup.

 

[CJim7]

No big horsepower just stock AMC 258 i6 / 4.2l . But do have 33" and don't plan on going any larger. Yes you are right truss is what I was thinking of just didn't know term. So if a motor swap is in far future trussing and welding AMC20 is what I'll need to do. In your info you say you have a t18a hooked up to a Dana 300 twin stick this is some thing I'm looking at doing to mine. Does the T-18 and t18a need an adapter to hook up to the Dana 300 ? Thanks for the info.

Trussing is something of a black art with the corp 20. Most people dont need it, those that do are running larger tires (35-36's and up) and committed to rock crawling. The tubes tend to bend when coming down hard off of an obstacle. Finess crawlers recognize this...and adjust their driving style for the corp 20 knowing it's limitations.
I've absolutely beat the hell out of mine on Volkswagon sized rocks...and I've just been lucky.
Welding is something I recommend with torque and hp. I dont think there's any way in hell my 20 would have stood up to the 430hp my 401 dishes out without it.
The Ford T-18 /T18a is the more popular swap since the Jeep T-18 's are getting hard to find. Yes, you need a ridiculously expensive adapter for the Dana 300 ...but it's worth it in my opinion. Advance Adapters and Novak carry the adapter.

 

[1986cj7]

Trussing is something of a black art with the corp 20. Most people dont need it, those that do are running larger tires (35-36's and up) and committed to rock crawling. The tubes tend to bend when coming down hard off of an obstacle. Finess crawlers recognize this...and adjust their driving style for the corp 20 knowing it's limitations.
I've absolutely beat the hell out of mine on Volkswagon sized rocks...and I've just been lucky.
Welding is something I recommend with torque and hp. I dont think there's any way in hell my 20 would have stood up to the 430hp my 401 dishes out without it.
The Ford T-18 /T18a is the more popular swap since the Jeep T-18 's are getting hard to find. Yes, you need a ridiculously expensive adapter for the Dana 300 ...but it's worth it in my opinion. Advance Adapters and Novak carry the adapter.

Ok thanks for the info I guess I'll run the middle range T-176 till it dies and deside where to go from there.

 

[Petescj]

Ok thanks for the info I guess I'll run the middle range T-176 till it dies and deside where to go from there.

I cant see you having any problems with the T-176 in your application. Ive seen them hold up pretty well behind mild 360s so your AMC 258 i6 / 4.2l wont overdo it.

When I had my 78 CJ5 I had the axle tubes welded by a professional. The tubes are thinner than say , a Dana 44 and are pressed into the center section. I was messing around in rocks alot and liked the sense of security. I also had a massaged 360 in it and didnt know how to stay off the "stupid" pedal.

I had a T-18 in my hands to slap in it after I broke 2 T-150s and had enough of the high gearing. The T-18 is what you want for any kind rock crawling. Shame that Jeep got stolen and sorts of legal happened afterward. Anyway Good luck.

Pete

 

[fzsk4p]

The one thing I`d do in a heartbeat is upgrade the Dana 30 shafts to the larger 760x sized U Joint. Dana 30 `s had the smaller 297x till the mid 90`s. Spicer U Joints are fine. You do not need anything more

However

If you keep the front axle locked and do much street driving.....The new Superior U Joint will hold up better then the CTM`s, Longfields etc.

Blaine designed these joints and did a LOT of testing before releasing them to Superior.

 

[Kane]

To answer your other question the ubolts are superior to the straps on the yokes.

 

[thejeeper]

Trussing is something of a black art with the corp 20. Most people dont need it, those that do are running larger tires (35-36's and up) and committed to rock crawling. The tubes tend to bend when coming down hard off of an obstacle. Finess crawlers recognize this...and adjust their driving style for the corp 20 knowing it's limitations.
I've absolutely beat the hell out of mine on Volkswagon sized rocks...and I've just been lucky.
Welding is something I recommend with torque and hp. I dont think there's any way in hell my 20 would have stood up to the 430hp my 401 dishes out without it.
The Ford T-18 /T18a is the more popular swap since the Jeep T-18 's are getting hard to find. Yes, you need a ridiculously expensive adapter for the Dana 300 ...but it's worth it in my opinion. Advance Adapters and Novak carry the adapter.

X2 on the AMC20 . It is a bit under-rated in stock form. The tube diameter is much smaller than most, and is dwarfed in comparison to the Dana 44 , Corp 8.25 or Ford axles however, the carriers are bigger than Dana 44 and Ford, therefore stronger. I ran a 430hp AMC 304 with roller valve train, ported/polished heads, flat top pistons and fuel injection to the AMC20 totally bone stock. Never "spun" and axle shaft or tube. That thing ate Mustangs for breakfast, mud for lunch and rocks for dinner.

With my 360, I trussed the axle housing, added single piece shafts and locked it up. I have no doubt that it will serve me well for many years to come.

Kudos on keeping the 20, by the way. It is, in fact, stronger than the Dana 44 . The biggest down fall to the 20 is the overall SIZE of the diff. She hangs pretty low. There are ways to shave it down if you are more serious in your wheeling.

Hope that helps!

 

[1986cj7]

Thanks for all the info and input. I don't plan on upgrading in the horsepower untill the AMC 258 i6 / 4.2l gives up the ghost and we'll go from there. But from the sounds of it the AMC20 can handle an upgrade in power with the mods I all ready have with the one piece axle. Unless I plan on doing some hardcore wheeling. Thanks again

 

[cymbash]

I run both the Dana 30 and the AMC20 with 33's. I look at it, this is what I have so run it till it dies. I have upgraded axles in both and arb lockers, welded tubes and I made trusses. I worked em' pretty good and they still survive. I have considered running 35's in the future and think they will be fine with some judicious throttle peddle. That is the key with any setup.

i see you have a amc 401 how did you address the oil pressure problem or did you fix it and how?