Seat Mounting Thread Repair

[Neil]

I'm hoping one of you Fab guy's might be able to point me in the right direction. 2 of my seat mounting threads are near stuffed and I'm having problems working out how to fix them. I have run a tap through both ,,, but the threads are now getting loose and its almost impossible to get a nut in the mounts with the seat in the way. They are 10mm x 1.25mm. I was thinking about welding the holes up,,,redrilling them and then re-tapping them but that sounds like a last resort. Thread inserts are not really a good idea because of the large outer diameter you have to make the hole and they are from what I can find a much courser thread. Any help would be much appreciated.

Cheers

Neil.

[Ben C34]

A helicoil would fix it easily. The hole doesn't have to be drilled out much larger and definitely can get the correct pitch.

I haven't repaired that exact thread for the seat, it have helicoiled other m10 1. 25 threads on the car no worrues

[GeeDog]

Drill and tap to a slightly larger size - the seatbelt bolts are 7/16 UNF thread, which is around 11mm. The bolts are readily available - every car uses this size for each seatbelt mount so the wreckers have heaps. They are just over 1mm larger in diameter, so very little metal to remove. Get seatbelt bolts off a Skyline & the head size is the same as the original seat mounting bolts - 14mm.

[Neil]

Thanks boy's,,,2 great ideas,,,think I'll go with the seat belt bolt idea 1st as I have everything here. You know i've been in the car industry almost all my life and I didn't know the belt bolts were all imperial,,,I knew the kids restraint bolts were but not the belts. You learn something every day.

Cheers and thanks again

Neil.

[GeeDog]

I only know because I've just fitted a harness, and was considering re-threading the rear tunnel side seat mount bolt to take a harness eye-bolt for the waist strap. Didn't do it because the adjuster would have been too low.