Jackshaft question.

[Tinkermech]

I am doing a timing chain/guide overhaul on my 2003 4.0 sohc Mazda B4000 and my rear jackshaft bolt sheered off about a quarter inch down from head of bolt. Question is can I just pull out the jackshaft after removing retaining plate to drill it out or replace it? Cannot find this info anywhere I've looked online. Any suggestions would be greatly appreciated.

 

[Tinkermech]

I found some obscure video online of an older gentleman doing a complete teardown of the 4.0. He had removed the oil pump first then the jackshaft. The only thing the shaft is interacting with internally is the pump at the rear. so out it came. In the vid. it was removed with the rear gear spacer. I took that off first not wanting to it to slide off internally. Now to see about drilling out the bolt.

 

[gw33gp]

Yes, the jackshaft does come out. You did the right thing by removing the spacer first. They usually don't fall off, but it is not worth taking a chance. I think there is a front and back on that spacer too, so put it back in the same way.

My brother, who is a professional mechanic, taught me a good way to remove broken bolts. Drill a good size hole without getting into the threads, then pound a Torx bit into it that is slightly larger than the hole. It works better than an extractor if you do it right.

 

[Eddo Rogue]

Ive had pretty good luck with extractors and eft handed drill bits. The key is a proper size and depth hole as centered as possible. Sometimes I use a right angle drill for the job.

 

[Tinkermech]

Thank you gw33gp, I had to center punch the heck out of it because it broke on an angle. The torx bit trick worked like a charm. The bolt was easier to drill out than I thought seemed pretty soft. Back on track with my project!