I recently did an auto to manual trans swap, and while dropping the trans many of times, 2 of the holes in the frame for the crossmember are starting to strip. It will get some resistance, then just loosen, and once or twice when i removed the bolt, i found pieces of the thread from the frame still on the bolt

Is there any way to fix this or am I SOL?

 

I've done the same thing. It's just something that happens on these cars. All you have to do is take a hole saw about an inch in diameter or maybe bigger and make a hole in the frame rail big enough to put a nut through and on the back side of a new bolt. You can go ahead and drill out the threads and use a bigger bolt. Go to the hardware store and buy Grade 8 hardware (bolt, washers, nuts).

 

where should i make the hole in the frame rail? Wouldn't it also weaken the frame if i dont weld the hole shut?

im kind of hesitant to do the myself because it seems like a swing or miss job

 

It will be obvious where you need to make the hole. Just on the side of the "subframe box" (I shouldn't use the words frame rail because these cars don't have frame rails) closest to the stripped hole. If you search there is a pic on this site somewhere of what somebody did.

I've had one hole in mine for over a year of daily driving now. I doubt it really weakens the body any appreciable amount. If you weld it shut you wont be able to get the bolt back off because you wouldn't be able to get a wrench over the nut.

You could also try re-tapping the threads.

 

The factory bolts are metric. If you want to keep the same wrench size on all the bolts, use a metric nut & flatwasher on the factory bolt.

It doesn't have to be Grade 8. Remember, it just holds a couple of pieces of sheet metal together. And, the factory "nut" is a self-tapping, soft bushing.

 

but i have two stripped holes so...wouldn't making 2 holes make the frame a little weaker?
because im looking to get a torque arm that connects to the crossmember bolts

 

I did the same thing on my T/A. You can either re thread the hole or drill it out
a little bigger, feed a bolt with a flat washer through one of the factory holes in the frame rail and then put a nut on the crossmember side.

 

how hard is it to re thread it?
or would it be a better bet to make a hole in the frame and put a nut in there

i pretty much want an option that would make it the strongest

 

i dont like the idea of cutting a hole in the frame. I would just drill the hole out and re-tap it with a slightly larger bolt, probably would be 7/16 or something like that maybe 1/2", or the metric equivalent if you so desire.

re-tapping is pretty easy, buy the correct sized drill bit and tap, drill out the hole, then run the tap through it, work the tap slowly with a tap wrench, dont put it in a drill... every couple turns, turn the tap back out about 1/4 turn or so to help clean out the threads

 

I had the same problem doing mine and after drilling and retaping for bigger bolts it worked great.

 

You aren't drilling in a critical load bearing area. There isn't that much force on the crossmember - what is loading it goes through a piece of glued rubber.

I don't have any choice but to make another hole, because the '82 chassis didn't include the rear mount holes, and the only way to get a nut up in there is to open a hole (you could go from the holes forward of the crossmember, but that's a long way away - and, another hole doesn't affect anything).

Think of the hole you make as weight reduction. . .

 

i have 2 stripped as well.
just get them in and snug and dont worry about it. once its in there, the force on it will keep the bolts from backing out on you.
ive done 3 tranny swaps and beat the hell out of my car at the track on a regular basis and never had one come loose.
maybe its my luck, but i think i would wing it.

 

Yep same problem. I just drilled them out and used a 3/8" heli-coil and replace all the bolts with 3/8" bolts to match. Tranny hasn't fallen out yet. You can also just drill and tap the holes to accept a larger bolt as others have done. I just happened to have the tap and heli-coils, so I used them.

 

Or just get 4 new bolts and retap them to a 7/16-14. It is a 10mm hole already, 7/16th is about 11mm. If I remember right, the 7/16th tap will just thread into the new hole without drilling.

I do believe that this topic has been covered before.

 

For those looking for another simple option for this fix using knurled inserts (sometimes known as nutserts) that will work to add another bolt hole, or repair stripped ones. See post here:

https://www.thirdgen.org/forums/susp...ml#post6108373