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And that's with the trans crossmember loose and adjusted all the way over to the passenger side. Right now the tailshaft is kicked out way over to the passenger side.... something is way off and I'm beginning to think it's the UMI solid aluminum motor mounts in the car, bc it did the same thing with the old engine/ trans in the car as well. Let me know what you guys think, I'm beyond frustrated!
The aluminum mounts should be identical from side to side so I wouldn't think that's where your problem is. My guess is the problem is in the kmember where the pedestals mount. One side bent slightly forwards or backwards. Or possibly both slightly tweaked a little. Did both motor mount bolts slide in nice and easy? Quickest way to straighten out the motor and tranny though would be to trim the motor mount some. Since the tail is towards the passenger side I would trim 1/8" off the back of passenger side motor mount where it sits in the pedastal and throw a 1/8" washer on the front to take up the space. If that isn't enough to straighten it out I'd take 1/8" off the front of the drivers side. You don't want any bind in the driveline anywhere so dont just keep everything loose to get bolts started then tighten everything up.
The aluminum mounts should be identical from side to side so I wouldn't think that's where your problem is. My guess is the problem is in the kmember where the pedestals mount. One side bent slightly forwards or backwards. Or possibly both slightly tweaked a little. Did both motor mount bolts slide in nice and easy? Quickest way to straighten out the motor and tranny though would be to trim the motor mount some. Since the tail is towards the passenger side I would trim 1/8" off the back of passenger side motor mount where it sits in the pedastal and throw a 1/8" washer on the front to take up the space. If that isn't enough to straighten it out I'd take 1/8" off the front of the drivers side. You don't want any bind in the driveline anywhere so dont just keep everything loose to get bolts started then tighten everything up.
Wrong the aluminum solid mounts are not identical and do have a specific orientation.
The aluminum mounts should be identical from side to side so I wouldn't think that's where your problem is. My guess is the problem is in the kmember where the pedestals mount. One side bent slightly forwards or backwards. Or possibly both slightly tweaked a little. Did both motor mount bolts slide in nice and easy? Quickest way to straighten out the motor and tranny though would be to trim the motor mount some. Since the tail is towards the passenger side I would trim 1/8" off the back of passenger side motor mount where it sits in the pedastal and throw a 1/8" washer on the front to take up the space. If that isn't enough to straighten it out I'd take 1/8" off the front of the drivers side. You don't want any bind in the driveline anywhere so dont just keep everything loose to get bolts started then tighten everything up.
The through bolts were a pain in the *** to get in even with everything being loose. I’m also thinking something is going on with the stock k-member and pedestals
The through bolts were a pain in the *** to get in even with everything being loose. I’m also thinking something is going on with the stock k-member and pedestals
If the big bolts were hard to get in I'd start looking there. I did a little looking around and as My-2k-z said, some of these solid mounts are specific in orientation. Just so happens UMI seems to be one after looking. They have a top and bottom but same from side to side. So if one was flipped it would raise or lower that side of motor by about 1/2". Worth checking out.
Ok so what I ended up doing was loosen all motor mount/ k-member hardware and ratchet strap the tailshaft of the trans over to the side I needed to align it. With the ratchet strap still in place I began to re-tighten all hardware and continued to check the alignment as I went. Everything is aligned as it should be now and from what I could tell something was definitely wrong with the pedestals, motor mounts and top plate of the k-member. I now have clearance for the passenger side header and tailshaft is damn near perfect. I did however, upon reinstallation, strip out the threads on one of the mounts on the car body for the trans cross member... can I just helicoil it?
Which crossmemeber are you running. I have spohn solid mounts, with a t56 crossmember for my th400. There is a gap exactly like yours. I then bought a spohn th400 spacer for like $30 and that bridges the gap perfectly. On my phone so cant dind the link.
Which crossmemeber are you running. I have spohn solid mounts, with a t56 crossmember for my th400. There is a gap exactly like yours. I then bought a spohn th400 spacer for like $30 and that bridges the gap perfectly. On my phone so cant dind the link.
After loosening up all the motor mount bolts it sat down onto the crossmember like it should. I just think everything was bound up from putting everything together outside of the car. It’s a UMI trans crossmember
Helicoil could work, or tap the next size up. What I normally do is drill the whole body nut out and weld a flange nut back in its place. As far as how you got everything lined up how much pressure do you think is pulling and twisting on the block at the motor mounts and now on the transmission tail mount also since its all bolted tight? Tail mounts have enough trouble staying together on their own without any other bind on them. And the motor I'm sure was torque plate honed to ensure perfectly round cylinders after the heads were bolted on. So why would you want to put all that stress on the side of the block now. I know it sucks to pull stuff back apart but a little extra time now will be worth it in the long run.
I don’t believe there’s any tension on the block/ motor mounts now. I think it was in a bind due to everything being assembled and tightened outside of the car.
Like I said the solid aluminum motor mounts are directional and need to be installed in a specific orientation. I have them on my car and they are very clearly different side to side.
09-30-2017, 12:25 PM
Th400 swap issues 
