'72 commando--TH400/Dana 20 mount ? - Off-Road Forums & Discussion Groups

Chrisfollin71 · #1 10-11-2009, 09:42 PM

I just bought my second jeep--a '72 commando wagon. I noticed that the front drive shaft was hitting the cross member when its rotated and it looks like the trans/t-case mount is some type of kluge. I think I have a T400 with Dana 20 with some type of 1/2" thick plate adapting the trans mount to the crossmember. I think I have this combo since the numbers all seem to match and I have a 258CI engine it. Can someone describe what I'm supposed to be seeing?

Tim · #2 10-11-2009, 11:00 PM

Should be an adapter between the 258 and TH-400 and another between the TH-400 and D-20. Might be spacers between the cross member and foot of the trans to xfer adapter, but usually spacers are on each side of the lower frame in between frame and cross member. Post some pics of what's in question to get a more educated answer. Welcome.

Pack Rat · #3 10-12-2009, 02:17 PM

There's a plate that bolts to the bottom of the transfer case to tranny adapter. The tranny mount bolts to that and the cross member. Hopefully the mount itself is just bad, worst case is one or both of the mounting hoes in the adapter are broken, real PITA if that's the problem. Could be the bolts are just loose too. And yes, TH400/D20.

Chrisfollin71 · #4 10-12-2009, 03:41 PM

Pack Rat, Tim,

Thanks. For some reason my search capability started working after posted this question and from what you said and from what I read it sounds like I have the factory setup and its a fairly common problem. I''ll drop the cross-member and see what I see.

C

Tim · #5 10-12-2009, 04:02 PM

Hopefully you won't find what's in the pic below, but it is rather common due to holes in adapter are threaded and bolts work their way out over time. This was welded back together, holes drilled out to remove threads and longer bolts with lock nuts on the other side was the fix to keep it from happening again.

Chrisfollin71 · #6 10-13-2009, 08:12 AM

Is that aluminum? I've welded mild steel with my 110V lincoln but that is it. My ride is pretty stock looking so I'm hoping it was neglected and not abused. C

Tim · #7 10-13-2009, 10:24 AM

Quote:

Originally Posted by Chrisfollin71

Is that aluminum?

Yes it is.

Chrisfollin71 · #8 10-14-2009, 08:08 PM

Tim,

I found one sheared bolt, one bent bolt, the aluminum around one bolt hole deformed, all holes hogged out, and one bad rubber mount. Did you put it back like the factory or did you modify it? It sure seems like modifying the cross member and/or moving the whole member back would be a better design.

Thanks for all the help.

Tim · #9 10-15-2009, 12:00 AM

Quote:

Originally Posted by Chrisfollin71

Did you put it back like the factory or did you modify it?

Both. Below shows what was holding it together when purchased, (a backyard Barney fix), followed by correct replacement parts and a couple pics showing finished product. The mod part was drilling the holes out in the adapter foot to remove the threads and using longer bolts that came out the other end allowing for flat washers followed by locking nuts. The original design required periodic inspection and tightening of the bolts with lock washers; otherwise, over time, bolts would loosen, slop would incur and the ears of the foot would eventually break.

Tim · #10 10-15-2009, 12:05 AM

Here's the diagram from the parts manual, followed by the description list. The short ones with threads pointing up labeled 3 were replaced with the longer ones, which I believe we pointed down, then capped with lock nuts.