I had this happen as well. Best advice I have, is to support the trans with a jack, get everything as close as possible, assemble loosely and make sure all bolts are started and finger tight, then tighten the mount bolts, then the crossmember, then torque all bolts when in place. You can easily break the mount bolts if it isn't lined up right.

 

Good thoughts. Will be a challenge as my crossmember is warped just enough across it's length to require some muscle to get it on the studs in the frame rail. And once it's on it holds itself in place with no bolts... Guess I'll have to be careful and work slowly.

 

And also - can anybody verify that the torque spec for the mount to crossmember bolts is 33 ft lbs? The FSM is very unclear.

 

Solved! As a mechanical engineer, this thing bugged me so I actually did some engineering: "research" and testing. I dropped by the local Jeep dealership and asked them for the transmission mount torque specifications. What I got was a printout of the front and rear motor mount torque specs. Which is fine since the transmission mount is formally known as a rear motor mount. Here is the pertinent information (PDF attached as proof):

Insulator stud assembly nut: 30 ft lbs
Support cushion / crossmember nuts : 192 in lbs (16 ft lbs)
Support cushion / bracket nuts (manual) : 55 ft lbs

Now Jeep offhandedly refers to the rubber mount as both the insulator and cushion. So what is the right specification? Well, I already had a ruined mount so why not test it? I stacked a couple washers and put the nut on. Hand tight plus a little more was MORE than 16 ft lbs. So I stepped it up to 30 ft lbs. And guess what? Somewhere between 16 ft lbs and 30 ft lbs the stud sheared off. I tried another stud at 20 ft lbs and felt things give just a little. So apparently 16 ft lbs is the correct torque for the M8 fasteners between transmission mount and crossmember.





At this point, assembly was easy. I lined everything up, got it all finger tight, then torqued everything. Drove around, bumped it around in 4 low, then retorqued again. I'll retorque after a wheeling trip this weekend, then before vacation to Colorado next week. Should be good to go!

One thing to keep in mind is that these mounts are, in my opinion, really poorly made. The threads are covered in rubber, and the mount base is uneven with excess rubber. So I chased the threads and wire brushed the base before installing.

Before:





After:

 

Not to completely threadjack, but what exactly is the spec on the crossmember bolt size? I thought it was m10x1.5 so that's what I used. Driver side went in fine, but the passenger side bolts popped out on the test drive. M10x1.25 fit perfectly and got me home but I'm scared to drive it until I figure out how m10x1.5 would even thread in to a 1.25 pitch hole or vise versa.

 

You're not threadjacking...in fact my post regarding the mount issues was more of a threadjack and you are on topic.

The crossmember to frame bolt size should be a coarse metric M10x1.5. That is what mine are/were and that is what I successfully chased.

Not sure how you found an M10x1.25 to work instead of an M10x1.5. Either you crossthreaded the M10x1.25 or you got the two bolts confused and actually installed the correct M10x1.5.

If things popped out on the test drive, you may have stripped the threads? Since the major diameter of an M10x1.25 is very slightly larger than an M10x1.5, the 1.25 may have been able to thread itself just enough to hold on your way home. Was it tough going in?

I would remove the bolts and inspect them. Confirm that they are the right (or wrong) size. See if the threads on the stud are messed up. Shine a light up into the bolt hole to see if the blind nut threads are messed up. You'll have a better idea of what to do from there.