Hello !! I have an original 10 Bolt in my 69' Firebird that I have a few questions.

It is leaking fluid from around the part that attaches to the driveshaft. So I need to replace that Seal.

Should I also replace the other 2 seals that are in the axles ?? If so, does someone sell a seal kit ? How would I replace them ?? I am on a budget so only want to replace if absolutely necessary (is there any possibility the seals are still ok after 40 years ?)
Thanks !!!

The first is a pinion seal..the other two are axle seals.

You will have to remove the pinion and definately buy a crush sleeve and then reset preload.

The axles, if leaking may need to check shafts to see if worn. You will remove cover, loosen bolts, pull shafts, replace seals.

Google or search here. Has been covered before.

ok, thanks !! So I take it if the axle seals were leaking then there would be fluid in the drum brake area, correct ? I think those are dry so it's probably just the pinion seal. Good thing you said to check the procedures, I almost messed it all up. Now I'll be sure to mark the nut position. I think this will ensure the preload is set back to where it was, but I don't know since I'm a rookie.

Could be the drum cylinders as well..the rubber does deteriorate over time.

I did mine without replaceing the crush collar, but kind of took a 50/50 chance. You may need to get the pinion bearing pressed off though. This was 10 years ago and haven't touched one since.

The pinion spacer should be replaced, but...
Some people(me for one) have good luck marking the pinion nut and housing with a chisel.
Then count # of turns it takes to remove the nut.
Do not turn axles.
After seal replacement, recount same # of turns until lining up the marks.

You can do this without replacing the crush sleeve. Mark where the pinion nut is and then when retightening it after replacing the seal, go another 1/4". This will usually take up the slack from typical wear. I have done about 10 so far without any problems. My car I race in the video link vibrated real bad at the track, I stopped racing that day and headed back home. It vibrated real bad to where I was going to call AAA for a tow but limped it home 60 miles!!!! I put it up on my lift and noticed the nut had backed off. I cranked the nut up to about 150lbs which still isn't enough to crush the sleeve any. Thats been 7 years since . Look at the link below ( My cameo in the Movies).
I dont baby any of my cars.

thanks for all the replies. I bought a replacement pinion seal from Rock auto and they said it was for 69' Firebird 350 10-bolt but it seems too big, the pinion shaft barely fits into the rubber of the new seal and really had to force it plus the o.d. seems a bit large (maybe I just need to force that into the axle housing. Any comments, where did you buy yours from ? Are there different sizes for the 10-bolt ????

looks like I got the wrong one... theres is 1.73" shaft size, the pinion I have is 1.94" (and the bore is different too). Guess I should have measured first..

I just called the local NAPA store, they said they have one in stock so I'm going to go and measure it to make sure it is the correct size..

This is the first part I've bought for it in 15 years so I guess I learned to be more careful when getting parts for it.

went to NAPA and they had the exact size in stock (doublechecked by measuring it with a set of calipers). cost about 10$, did what you guys said here and it installed good. Once I get the Bird running, I'll see how it works, should be ok !! Thanks !!