Thread Repair

Submitted by bill on

Thread repair on alternator bolts.

The bolts/washers (91611-61030) are discontinued at Toyota. I split an old die, used a small vise, stepped back a few threads and recut the ends inside out.

split die



June 11, 2016

Checked the alternator mounting bolts today, hit them with some Kroil - they don't seem too rusted up and seem to move. Look original too, number 6 or 9 on all three bolt heads I think. One bolt has always been bottomed out/loose, probably because of the missing hook/spacer. The alternator bracket is mounted flush with the head and the lifting hook goes on top of the alternator bracket, not behind it on the head.


alternator diagram

June 14, 2016

OK, so the PO strikes again. Pulled the top 2 bolts to mount the new engine lift hook from kiwidog. They came out but not too free and easy. Examined the ends of the bolts and the threads seemed a little strange, shiny worn on the ends and one bolt didn't seem to want to go back in easily. So I decided to pull the alternator, mounting bracket, clean everything up and check out all the threads more closely. I like to be careful with tapped holes in the block, etc.

I'm thinking somebody pulled the engine hook when working on the alternator in the past and tossed it. Then they reinstalled the bolts, the two top ones now being too long and just bottomed them out in the block, messing up the threads on the ends of the 2 top bolts. They could have at least added a few washers.

So chasing the threads with a tap in the block (carefully) and no available new hardware (for this anyway) from Toyota, can't get a die started cleanly on the bolt ends which are not in great shape.


worn thread 1


worn thread 2


worn thread 3