Amc 20

[Old Dog]

Well I finally did it, I twisted the driver side tube.
The funny thing is we were on a clean-up ride so we didn't
hit any of the big obstacle's, and I had my 33 mtzs on not my
35's on beadlocks.
I never welded my tubes as I wanted to see what it really took
to break it. I still don't know as I check the jeep everytime I
get back from wheel'n and it wasn't like this last time, and we didn't do
anything tough this time.

 

[Petescj]

Your really putting a hurtin on that poor CJ7 these days. Bent springs , cracked fenders and now a toasted AMC20 . Your on a roll my friend.

I have a wide trac AMC20 for you free. You just have to pick up.

 

[Old Dog]

Your really putting a hurtin on that poor CJ7 these days. Bent springs , cracked fenders and now a toasted AMC20 . Your on a roll my friend.

I have a wide trac AMC20 for you free. You just have to pick up.

I know it's been a bad year so far. Must be because the wife hasn't been going with me.

Thanks for the offer of the 20 but I have a 8.8 here that I have been working on. I just need to get e-brake shoes and a e-brake handle to hook up. We have a club ride comming up in a couple weeks so I have to get off my butt and get it in.

 

[dalefan88]

Your just having to much fun if your braking stuff lol


Sent from my iPhone using Tapatalk

 

[tarry99]

old dog,
so do you think that is from a twisting torque motion or bending the tube in an up & down motion?

 

[Old Dog]

old dog,
so do you think that is from a twisting torque motion or bending the tube in an up & down motion?

It looks twisted ie. the yoke is pointing up more than it should be.

Now that I've thought about it...the pass. side u-bolts needed tightening after the ride before this one (natural bridge) that was a rough couple days, something might have gave out than and just now showed it's ugly head.

 

[Sasquach]

I'm puzzled how that could happen since it is a torque type failure and not bent?
If twisting is all that happened then looks like it would make good sense to skip weld the tube for the rest of us anyway.
What do you think?

 

[Old Dog]

I'm now a believer that the tubes need to be welded.
Although I have to say that it took alot in the 6 years I've been running it.

 

[Sasquach]

I'm now a believer that the tubes need to be welded.
Although I have to say that it took alot in the 6 years I've been running it.

I'm impressed

 

[tarry99]

Old Dog,

When did you bend the springs? Was it that side?

 

[Old Dog]

Old Dog,

When did you bend the springs? Was it that side?

I bent the front spring on the same side last time out.
I stuffed the front tire into a big rock comming down a 10' rock.

 

[tarry99]

Old Dog

Yep the plot thickens........are those 20's high pinion or standard?
The direction of the rotation of that tube seems opposite of torque so that "high dive" off that 10 ft rock makes a lot of since............let's score that a 9!

 

[Smokinjoe101]

To weld an AMC20 tube is that best done removed from the vehicle or can one weld the tube without removing the axel?

sj

 

[tarry99]

Smokinjoe

I think that depends on several things:
How good of welder are you?
The ability to get the weld zone clean?
The ability to get around 360 degrees under there and still do a good job.
I would also think you would want to drain the oil, but even doing that , whats left in the tubes could get burnt and catch fire.
I think most of the guys with these axles like to stitch weld around the tube to the housing in 4 evenly spaced spots.

One last thing which may end up being the most important is that this housing is made out of nodular Iron, the good news its a lot better than cast Iron, "BUT" you should also follow normal procedures for welding nodular Iron which is pre-heating & post heating the weld zone and let the temperature cool down slowly, this is best done using a small space heater with a welding blanket over the weld zone. It also requires special welding rod. I like to use 309 or 312 Stainless Rod w/ the 312 being a little better.
This is the correct way but I'm sure there will be other suggestions so go with whatever you feel is right.

 

[Old Dog]

I would want to take it out and also pull the carrier and bearings.

 

[Old Dog]

I also found the pass. side perch is toast.
And the pinion is pointed up just a little higher than normal.

 

[tarry99]

Old Dog,

WoW , That's a lot of force , I guess all combined that damage you did a few weeks back looks to be a contributing factor............ya just never know what will break next and how that force transfers up & down through the chassis or axles.................I'll upgrade that score on the "High Dive" to a 10.

Have a beer on me!

 

[AussieCJ7]

Well I finally did it, I twisted the driver side tube.
The funny thing is we were on a clean-up ride so we didn't
hit any of the big obstacle's, and I had my 33 mtzs on not my
35's on beadlocks.
I never welded my tubes as I wanted to see what it really took
to break it. I still don't know as I check the jeep everytime I
get back from wheel'n and it wasn't like this last time, and we didn't do
anything tough this time.

I did exactly the same thing also on 33's and while I like to play I dont like to abuse my toys It was fine for 14 odd years with a 4cyl but only took a few trips with 4.0L and 33's

Like you I did notice the opposite side ubolt came loose and it broke the spring locator pin when it happened so not sure if that was the cause or the symptom but guessing part of the cause

I put a scout Dana 44 with a homemade truss in mine as the cure

 

[Old Dog]

I like to play I dont like to abuse my toys It was fine for 14 odd years with a 4cyl but only took a few trips with 4.0L and 33's

I put a scout Dana 44 with a homemade truss in mine as the cure

I don't hammer on mine either, mostly slow rock crawls, But I did have
some pretty good wheel hop the second day. I don't know if that did it
or if it was because of it as wheel hop isn't usually a problem.

My cure is going to be a 8.8, and I will weld the tubes.

 

[Incommando]

If swapping to an 8.8 it is a good idea to get a disc rear so the calipers aid in axle retention or go to an aftermarket axle retention device. Although not nearly as bad as the old GM 10bolt about losing a wheel/tire assembly when you snap an shaft. Things like the D4r4's superior axle rettention is often overlooked in the "strength" arguments