brotherGood

Since this car sat in a barn for 15 years, I want to be proactive and go ahead and change the diff fluid. Obviously, I'll put a new cover gasket on, but I had noticed on the pinion side it looked a little dark. Is there a front seal on this that can be replaced without messing with the pinion nut/backlash/can of worms?

Alternatively, being that it sat so long should I bite the bullet and just get it rebuilt?

JohnnyBs68S

You'll need to remove the pinion nut and yoke to replace that pinion seal. Mark the nut position WRT the pinion and re-tighten to that point on re-assembly to maintain something close to the proper pinion bearing preload. None of this should upset the gear engagement or backlash.

bccan

If I didn’t see a wet leak at pinion or either end of tubes, I would change oil and call it a day. If you find something amiss, fix it, if old oil is really nasty, change it again after driving it for a few months or a year.

brotherGood

WRT? I'm kinda lost on that one. I think I've got the jist but not sure what that means.

I can't tell if the wet near the pinion is old, new, or even overflow from when someone serviced it once before.

brotherGood

Now that I have much more of an understanding for a deadline on the engine build, I need to get the ball rolling on pretty much everything else.

I think after consideration, I'm going to have someone go through the entire diff and rebuild it. I'd like to add a Posi unit if I can as well. Anyone have any tips/tricks/links on how best to gather parts?

Thanks.

JohnnyBs68S

Sorry, just seeing this. WRT = with respect to (as in marking the nut relative to the pinion so when you tighten it back up, you can re-achieve the exact same position of the nut relative to the pinion to restore the bearing clamping- and pre-loads). Moot point now if you are going to have it rebuilt. Monaz on here can provide posi parts and gears. I got my posi from Supercars Unlimited and my Richmond gears from Jegs or Summit, crush sleeve, axle bearings and seals from RockAuto.

brotherGood

No worries.

I PM'ed Monaz about a week ago, but that was before things got rolling and I didn't have any urgency. I plan on doing a deep dive/parts order this weekend..Ill check out Supercars & Summit/Jegs.

Thanks.

BangScreech4-4-2

I will go back and look through my paperwork as I re-did my Type O over a decade ago, but my recollection is that even back then the shop had to adapt a posi carrier from an 8.5 inch corporate rear out of a Pontiac due to lack of availability of Type O parts. I will double check and confirm as soon as I get a chance.

Fun71

There are new posi units that are Ford 8.8 carriers that are machined and drilled for the O-Type bearings and ring gear. Monzaz would be the go to guy for this as well.