1999 blazer with 120,000 on it, runs klike a champ and I love it. but the rear went yesterday. Pinion has 2 teeth off it. Should I put a new ring & pinion in it with probably new bearings, or look for a whole unit to change out. thanks

 

That depends on your experience level, what tools you have available to you, and how much longer you plan on keeping the vehicle.

A new rear end will cost more than a set of gears and will take an hour or two for two people to swap in provided everything comes apart good (brake lines & parking brake cables especially). With any used part, life expectancy can be iffy.

New gears & bearings will recondition your axle to 'as new' specs. If done correctly, you can expect it to last another 100k+. But setting up a rear end properly takes experience and the proper tool set to do the job.

 

See if you can find a rear from someone trustworthy with lower miles on it.. get a Price. Compare with Ring, Pinion, Bearings and seal price.
I have to wonder why the Pinion teeth broke. Are you hard on teh vehicle? Did the Pinion nut loosen causing the Pinion to pull in for many miles until they broke?

Just a faulty pinion that took 120K miles to finally show it's defect?
I have done it both ways on various autos.
Just recently swapped out the rear on my daughters 1999 with about teh same mileage as you. I tried new Pinion bearings and outer bearings. I have the proper tools to set up the Pumpkin and I could not get this rear to coorporate. I think the previous owner bent the housing ..
The Junkie rear has been in for over 6 months now. Nice and quiet.
I found it easier to slide teh axles on teh replacement rear and pull the Dust shields off. Doe the same with the rear in your Blazer so you can keep all the E-Brake stuff intact. You probably want to drain the fluid and eyeball the inwards anyway. not much more work gets the axles out. Easier to get in between the Leaf springs and frame without teh Dust shields as well.

 

It was making some noise for a while like whinning when I let off the gas and then it sounded like I had a card in my spokes on a bicycle, then it got real loud bang,bang ,bang. No, I'm having it done by a friend that has a reputable shop, He found one for me,supposidly a good one out of a salvage yard for $350.00 complete. He said that would be the cheapest way to go. Otherwise we'd have to buy ring & pinion, bearings,seals, maybe backing plates and still have to have him it set it up properly, so I'm happy with his decision.

 

I'm sure he popped the rear cover and took an eyeball on the gears as I did when I did mine. If he feels good about the rear .. At $350 it will be cheaper to just swap them out. Good Luck

 

Yeah, that's a good price on a used rear. Definitely pop the cover. Not only will it allow you to make sure that it is in good health, it will also allow you to confirm the ratio.

 

thanks for all the support and help guys