Transmission x-member woes

Happy Easter everyone. Yesterday after the oil change I had the bright idea to finally replace the transmission mount since I had bought a spare about a year ago. What a mistake that turned out to be! When I saw a missing nut on the mount's screw and a sheared bolt holding the x-member I should have called it a day and saved the project for a better time. Undaunted though I forged onwards and there was considerable carnage (or is it truckage?).

I could not get the nuts off the bottom of the mount. They were stuck real good and incredibly rusty (you may recall from my project thread, this has been a consistent issue with my truck) so they just rounded right off. I thought then I would unbolt the four large bolts on the transmission that hold the top of the bracket, and one of those sheared off and of course the two inner ones I could not reach with the sockets and did not have enough torque with the wrenches. So then I went to unbolt the x-member from the body, the driver's side went pretty well but the passenger's side was a complete disaster, all but one of the bolts sheared off. With the x-member now loose from the body but the rubber mount still attached, I was able to get in with the sawzall to cut enough of the rubber mount away so that I could wedge it out of the way enough to get the socket on the last two transmission bolts and remove the entire x-member/mount/bracket assembly.

Whew, with that out it was time to go to town on freeing the mount. That took a long time and many dremel cutting discs. And unfortunately I discovered there's a ton of rot on the x-member itself, which will need replacement as soon as I can get a spare. No pics since I was in a huge rush to get this back together. I was able to attach the new mount to the bracket, attach the bracket to the transmission, and then stick the x-member back on the body. It's secured with what I have left of the hardware:

one nut on the passenger's side (there's actually what seems to be a study poking down, not sure if this is normal or what's been buggered up by previous owners/mechanics)

two bolts on the driver's side, there's also a third but whatever it threads into broke off so it was just spinning in place

one nut holding the mount to the x-member

three bolts securing the bracket to the transmission

So obviously I have a lot of fixing to do here this week, hopefully it's at least strong enough to veeeeeerrrry carefully drive. I'm guessing I'm not the only one that's run into this, are there any recommended repairs? I was thinking I would just drill the bolts out of the body and then feed nuts down from the top, get everything in place and a tad of j-b weld to help keep them from moving for later uninstall. I'm not sure if there's enough clearance to do that for all 8 holes though (I didn't have much time to inspect). The transmission should be an easy fix, and I just need new bolts for the mount. Stainless and anti-seize all the way. Are there any "better" replacements for the x-member or can I pull one from any clean XJ?

The worst part is, once I got the new mount in, it didn't seem any different than the one I replaced! :doh:

Repairing the frame nuts shouldn't be too hard for you. It will simply take a few good drill bits and a 10mm x 1.50 tap. You should already have this tap because the rear bumper nuts in the frame are the same size. I recently had to do this with my 86.

Just make sure the XJ you get the X-member from also has the AX-15.

As far as the crossmember, there are several companies that make a heavy duty model that will work for both the MJ and XJ, auto or 5-speed tranny, like THIS ONE.

The AW4 and AX-15 crossmembers have different part numbers, but either will work on your AX-15. If you use a crossmember for the AW4, the tranny will set up higher about 1/2" which will be okay. Both the AW4 and AX-15 use the same tranny mount too. If you get a crossmember from the JY in your neck of the woods, use a late model one from an XJ as it will probably be less rusty. :yes:

Will the t-case linkage still align correctly without the x-member recess since it pivots in the trans tunnel? I don't know so I'm just asking.

Will the t-case linkage still align correctly without the x-member recess since it pivots in the trans tunnel? I don't know so I'm just asking.

Good point Mike; and I'm not sure. I just know they are interchangeable in the 2WDs. Someone should know this for sure. Maybe JeepCo?

I need to replace mine too. I am so not looking forward to this. I realize pbBlaster is your friend but there are a couple of bolts on the cross member that go up into the frame so there is no way to spray them. I hate the thought of starting this little project. :ack:

As far as the crossmember, there are several companies that make a heavy duty model that will work for both the MJ and XJ, auto or 5-speed tranny, like THIS ONE.

That looks pretty good. Any supporting vendors here carry that or something similar?

As far as the crossmember, there are several companies that make a heavy duty model that will work for both the MJ and XJ, auto or 5-speed tranny, like THIS ONE.

 

That looks pretty good. Any supporting vendors here carry that or something similar?

Went with RockAuto for under $150 shipped, seemed to be the cheapest around with the discount and I've bought tons of stuff from them over the years. Ugh, expensive week already. Tires for the Camaro, rack and pinion for the Camaro, x-member for the Comanche... :roll: :eek:

Yep, seems like stuff breaks in bunches. :( So which cross-member did you order from RockAuto Jon? I don't even see them on their site. :dunno:

So which cross-member did you order from RockAuto Jon? I don't even see them on their site. :dunno:

I went with the same unite you posted, the RuggedRidge/Omix-Ada. I actually just used the part number search (12035.60) and bypassed the vehicle selection; I believe it's only listed for the Cherokee in their database.

I see. Looks like it mounts with only four bolts, not eight. That will make less work for you. Please let us know how it works out. :cheers:

This has been a real bugger of a job. :fs1: Time for some good Cobalt bit sets.

Looks pretty good.

Nice and thick.

Rolled edges front and rear.

Pretty nice welds, some spatter.

Swiss cheese.

And some crappy phone pics to round this out. I buggered up one of the threads on the framerail mount (after I had fixed it) so I still need to drill and tap that up to the next size. But, it's in there.

Hell of an improvement. That thing looks strong. :cheers:

If I crawled under one of my Jeeps and saw something like that,,,I'd have to go change my drawers. :doh: I only have the deepest respect and admiration for those who tackles this crap and restores it. :bowdown: Nice going jeepcoma :cheers:

Hell of an improvement. That thing looks strong. :cheers:

For sure, weighs about 2-3x more too. I was a bit concerned about the 4 vs 8 mounting points but now I see it's totally not necessary. Wonder if the thing acts as a stiffer frame support too?

If I crawled under one of my Jeeps and saw something like that,,,I'd have to go change my drawers. :doh: I only have the deepest respect and admiration for those who tackles this crap and restores it. :bowdown: Nice going jeepcoma :cheers:

Well thanks. Most days I feel like giving up and just throwing in the towel and am disgusted at how much time and money I have dumped into this thing. Really, this little bit was nothing after just about everything else I've had to fix. And I should have know better before tackling the project as this was one of the last virgin bolts I hadn't touched yet, so I really wasn't thinking when I though it would be a quick job to swap the transmission mount. I figure now that if I knew everything I would have to do before I made the purchase, I would have passed it over and bought a truck in better shape (when your spring mounts look like swiss cheese... :eek: ). But it's been slow and steady progress. There's really nothing too it, you just have to have more money than sense, as a regular person would have bought a perfectly nice Ranger or something and not have had any of these problems.

hey everyone, sorry to bring back an old topic but my searching is coming up short. I had an unreliable mechanic change my clutch in my 1988 4.0 ba 10/5, and he forget to put in the bolts that go through the transmission mount into the tranny, that hold it from sliding. i cannot find the bolt size or thread for these four holes, can anyone help me out?

hey everyone, sorry to bring back an old topic but my searching is coming up short. I had an unreliable mechanic change my clutch in my 1988 4.0 ba 10/5, and he forget to put in the bolts that go through the transmission mount into the tranny, that hold it from sliding. i cannot find the bolt size or thread for these four holes, can anyone help me out?

The Jeep part number for these bolts is S0180144. The dealer might be able to cross it for you.

Long-term update to this thread.  I recently purchased the Novak cable shifter adapter kit SK2XC to replace my broken stock linkage.  I thought it would be an easy plug and play deal, but the Jeep gods frown upon such talk so I was cursed with trouble.  Naturally, I had to cut the original linkage system off the body.  This resulted in nicking the plastic clutch line with the cutting wheel (on the last bolt, no less).  OK, fine, I wanted to upgrade to the stainless kit from Advance anyway as mentioned in this thread.  Naturally, they are closed for the holidays, so I was forced to find a fix so my wife can get to work.  I managed to rig a temporary repair by flaring both ends of the plastic clutch line and slipping a reinforced rubber fuel hose over both ends and using some hose clamps.  Then I was able to get back to trying to get my 4x4 linkage working.
 
Anyway, what I found out after way too many hours laying in the snow in sub-freezing temperatures is that I couldn't get the transmission-side bracket to fit.  There wasn't enough room for me to get the bracket over the studs without hitting the shifter housing that extends down past the tunnel panel.  It turns out, which is obvious from the pictures but I didn't think of until I couldn't get things to fit, is that the Omix-Ada transmission x-member is a couple inches thicker than the stock unit.  Instead of thinning out in the center where the transmission mount goes, the new unit is just a flat piece of metal all the way across, which eats up an inch or two of space under the tunnel.
 

So now, instead of a marginal 4x4 linkage and stock plastic clutch line, I have no hope of getting 4x4 working for the winter and the temp fix is a ticking time bomb until I can get the parts in and have the time to replace the line.  As always, one step forward and three steps back.

Happy New Year!