Broken and Stripped Trans mount bolts

[HAWKER]

Has anyone ever fabricated new bolts to hold the rear trans mount up. What is entailed in getting a new bolt in there or possibly repain the stub of an old bolt?

[scarlson]

The PO of my 78 drilled out one of the studs and put a bolt through. To get the mount off, I had the wife hold a wrench inside the car while I went under with another to get the nut off. If I had a welder, I would have tack welded the bolt to keep it from spinning

[HAWKER]

hey, I appreciate the help! Do you thing the old bolt in the floor pan or was welded or pressed in before th PO drilled through it, allowing the new bolt to spin. Do you think that was a good fix or do you think taking the old bolt out completely would have been better and practical. I am getting ready to pull the seats and try to find the head of the bolts as most are stripped and fatiqued. I am hopeful that they will tap out from the bottom and new carriage bolts will lay in there nice and not require a weld as I to do not have a welder. It is a mystery tour as Hate to tear out the old bolts but they seem weak and will have to go to a smaller die if i rethread them. One of these bolts ils a half inch long. It is the only one with good threads.
Thanks again
Hawker 630 781 5138

[scarlson]

I think the original "bolt" is welded in place. It is not really a bolt as it has a button looking head. Hopefully this pic shows so you can see what I'm talking about. You'll have to ignore all the white phosphate. I'm cleaning up the rust with some naval jelly at the moment.

Drilling out the bolt worked ok. The new bolts head sat on the old one and made a bump under the carpet though. If I were to do it, I would take a grinder to the head. I think the shank could then be knocked out with out too much effort. Alternatively, you could use a punch to mark the center of the head and just drill it out. You might be able to use some jb weld or other epoxy to secure the bolts. As I have not done this repair, things may go differently once you get into it.

Make sure to use a decent grade of hardware so the new bolts don't break off on the next repair or worse while going down the road.

[kmac33]

I had one of mine "strip out" when I removed my tranny. You do not even have to drill it out. I was able to just "pop" it up into the passenger compartment with a tap of the hammer. I used JB Weld to secure the new bolt in. I would have tack welded it, but I didn't want to deal with removing the carpet and Hush Mat that the welding would have required.

[HAWKER]

Thanks guys for the help, This is good info. I actually was able to tool some new but weak treads onto the old bolts, one of which was snapped off but usuable, I hope. I have a rebuilt engine and trans all hooked togeather laying in the garage and I am dieing to get it in and hooked up. My waranty exspired while waiting for other solutions. Sound Familiar. I have learned a lot as we all have and I hope I can contribute to the site. Everyone has been great!
Hawker

[pope]

The first trans mounted bolts have a thick metal tag that allows the pressure to be spread out. The second bolt is just tack welded in place. The front bolts are about 1 1/2" long and the second one should be a little over 1". Dont short yourself on the length of the bolt

[HAWKER]

Hey Motown,
Thanks for your response to this trans bolt issue. Your pics are great, however I have the whole cocpit cleaned out and I cannot find the top of the drive shaft bearing support bracket bolts. One of those bolts is a real problem as it is only a stub and I currently have a lock nut on there hanging on for dear life because the threads that were there are pretty much gone.
From under the car these bolts seem to come up exactly under the seat rails which adds tremendous extra effort to the repair. Is your second pic a pic oftop of one of those bolts and if so did you have to take off the seat support rail to get to it. That rail looks like it is welded in.
Thanks,
Hawker

[pope]

Yes, there are three set of bolts. Second set has its heads under the seat rails. I have since removed all the rails and will be fashioning new ones. I don't know of an easy way to do it.

[HAWKER]

Thanks for the quick response, with your guidance I may drill up from the bottom through the seat rail to locate the exact location and then open the hole in the rail with a hack saw or drimmel saw to ge a good look at at the location. Then I might be able to drop in a new bolt with a thin locking nut on the bottom. This is motivation, may be I should buddy up with a welder ace.

[pope]

There is a crossmember that the seat rails attach to. The crossmember has a front facing 1/2" flange that is spot welded to the floor. It is at that flange that the bolt goes through, so it can go through two pieces of metal for support. The bolt head on one of mine sits half in/out of the seat rail. You may have to cut a 2" opening in the rail and fold that side up to work on it, repair it and fold it down again to re-weld it somewhere.

[HAWKER]

Thanks Pope, that is good stuff!