transmission mounting problems

[zvinner]

I have recently rebuilt the engine on my 1990 300zx. When I put the motor back in and started torquing the transmission cross mount, only one of the six bolts torqued to spec. The others just spun. I'm thinking of drilling and tapping the holes to the next size, but I don't know what's in there. If it's a nut welded inside the frame I'm afraid that going to the next size is a bad idea.........

anyone have a suggestion?

[evildky]

Welcome to Nico!I've not had any experience with the trans crossmsmber on my Z32 but I'd assume you should have some sort of captured nut that the bolts go into, take the one taht torqued ok out and look inside with a flashlight, you'll see the nut threads in there, the other might have simply slip out of place, I have no idea how easy or difficult it'sll be to get them back or how far they car go

[My Harley]

Hopefully I am not too late. Helicoil/ permacoil is the answer. Search for toolsqwik.com. The bolts are M10 x 1.25. I had to permacoil 3 of the six and retap 2 others. Take you time, work slow and they're like new. Recommend that you either rethread each bolt or get new ones. Don't force them like the rocket scientist who originally jacked up mine. Let me know if you have any questions.

[zvinner]

I've looked into helicoil, and I don't know that they'd be any better than just going to the next size bolt. You have to drill out and thread for the helicoil anyways... I'm just wondering how much material is there for me to tap into. I guess there's only one way to find out........thanks for the suggestions