I just installed a new starter last week using new 3/8 x16 1.25 long bolts. Yesterday the pinyon gear just started spinning on start up. On removal I found the top bolt was slightly loose and the pinion gear was stripped down about 1/8 for an inch all around.
On a thread from 2010, it was stated that these bolts should actually be metric!
Is that true? The old bolts I removed were 3/8 16 verified with a die when I was cleaning them up.

Also, what is the correct torque for these bolts. Couldn't find it in my Haynes manual.

Thanks for your help.

Chuck M.

 

Should be standard like you thought. My Haynes says 15-20ftlbs. Put a lock washer on the bolt before you install it. Or put some blue Loctite on the threads.

 

They are fractional.
I think all driveline components are, in this era.

Maybe someone in that thread just butchered their way through?
The metric bolt close to 3/8-16 would be 10X1.5.

I never thought to torque my starter.
probably about 20-25ft-lbs given the crap metal you are likely threading into.

ETA: I stand corrected.
15-20 '# it is...

 

Thanks guys,

Good advice - I just want to make sure this thing doesn't keep coming loose.

On the metric size, I double checked the thread I saw that on and it was an FTE Diesel forum from 2009-2010.

 

Oh, that would make sense on a later engine.

I had some major starter problems a couple of years back and had to helicoil my bellhousing to get the bolt to stay tight.
But that was because of the starter(s) destroying themselves.

 

Jim,
When you say your starters "destroyed" themselves, what damage were they doing? Was it taking the teeth off the pinion gear? Thats what this new one did for me. It was a cheap starter ($65) from O'riellys but with a "lifetime warranty". Is the pinion gear one of the weak points on a cheap starter? Maybe I should upgrade to a better quality unit.
Thanks,
Chuck M.

 

It's an epic tale.

I had changed my flywheel when I went to a ZF5 gearbox.
It was a Dorman branded replacement flywheel for a '94 460 and came with the ring gear installed.
After that, I had starter engagement problems.

The support bushing would wear oval and the pinion would skip on the ring gear, worse and worse until it would not turn the engine over.
Sometimes the pinion gear would end up in chunks.
In some cases the whole 'snout' would break off the starter.

This resulted in starters coming loose and I had to replace the bolts when they bent.
I had to Helicoil the threads in my ZF bellhousing too.
Locktite didn't help.

I went through a half dozen starters in as many months.
I tried "Lifetime" warranty from Advance.
At four, they would no longer give me a new one claiming I had a bad ring gear even though they sold me the flywheel.
I tried Motorcraft from the dealer, but the counterman told me that they were all rebuilt and not all started life as OEM
I decided I was going to try a PMGR starter as would have come with my '94 flywheel and gearbox.
I bought an inexpensive ($65 new) Chinese starter from DB Electrical on Ebay.
Killed that one too...

I started a thread and did lots of measuring.
Seems to be the fault of the ring gear, but I could not deal with dropping the transmission to change it.
I ended up pushing the starter into better engagement with the flywheel after slotting one of the holes and changing the piloting diameter.

I am using a "cheap" -but new- DB Electrical at this time, and it is holding up fine.