My lower alternator bolt is seized up. I've put PB Blaster, WD40, and an industrial rust buster on it. Still no luck. I've bent a wrench and almost rounded the head of the bolt. I can still get a wrench on it, but if I put any more force to it, the bolt head will be completely screwed up.
Any tips for removing this bolt?

 

It's a 1993. Sorry forgot that part.

 

Use only 6 point wrench, or socket. Occasionally you have to destroy a bolt to get it out on these old trucks. Good luck!!

 

Sawall the alternator where the bolt is to brake the bolt inside alternator

 

Thanks! I managed to get it out. Threads are rusted pretty badly. I had to use a prybar to force it as I turned the ratchet... Think a new bolt will go through?
Also, there's not much room to tap the threads... Ideas?
I thought maybe using a smaller diameter bolt, but I don't know if that would cause the pulley on the new alternator to wobble and wear out the shaft or bearing.

 

Get a new bolt and nut you will be good to go.

Being as you have the head all ready rounded part way off.

 

Get a tap (you have the bolt out, so measuring should be easy). Since you're just "chasing" threads, you can use a taper, plug, or bottoming tap. (Plug is most likely type you'll find at the hardware store.) Use oil; if there is damage to the threads (which is WHY you're chasing the threads) oil will help keep the tap cutting correctly.

 

what threads?

 

are the later alternators much different than the late 80s? the lower attachment on my '87 has no threads to chase. the bolt runs through tabs on the alt and mount, secured by a nut at the other end. if replacing the bolt, i'd replace the nut, too.

wally