TH400/t-case x-member (1 Viewer)

[bsilva132]

This isn't really hardcore but there are more garage fabricators in here then the general 40 forum.

I am reworking the rear d-train x-member in my buddy's FJ40 (350/TH400/3spd tcase). Rig is a mild wheeler and the rear x-member is currently the standard AA propeller mount which is causing a leak at the rear of the t-case.

I plan on fabricating a new x-member that mounts to the foot on the TH400 to t-case AA adaptor. I was planning on using some 1x2 box tube but was wondering what thickness I should use? 1/8? 3/16? 1/4?

 

[jc71fj40]

Hey Brian,

Hope things have been good for you.
I have been running my existing th400 cross member for years with zero problems.
Im almost positive its 3/16th 1" x 2", with homeade 1 3/4 dom and urethane bushings at the frame.

Hope that helps
Jake

 

[bsilva132]

Thanks Jake. Things are indeed going well. I already have an energy suspention urathane trans mount will pick up some 3/16" 1x2 from c&c on my way home from rancho.

 

[shelfboy1]

running a 2x2 x1/4 on our monster truck with a 203 case ,despite what we throw at it its held up well so you should be fine .

 

[reddingcruiser]

I have generally avoided rear mounts that are incorporated into the skid plate. But after seeing several well done versions, I am inclined to go that route, first on the FJ40 currently under construction in my shop and then on my own 40. It eliminates issues with the right side frame mount and makes it easier to get clean lines on the skid plate.

 

[mookie]

I made My th400 crossmember from 2" round tube .120 wall, and it's holding up fine. Imo though you still need something supporting the back of the t-case whether its a separate crossmember or just something that ties back into the trans xmember. The tail-housing on th400's is a major weak point. Also imo, If you do go with separate x-members use the same frame attachment type as the rest of your drivetrain so they all flex and move the same....i.e if your engine is mounted at the frame with AA donut bushings then do your trans and tcase mounts the same way.