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The purpose of this post is to reach out to people more knowledgeable than myself to evaluate the condition and determine the viability of the planned re-use of a used ring & pinion. Recently, I purchased some used 8.2” Pontiac 3.23 gears. The previous owner stated that the gears ran fine and that he wanted to simply upgrade to a lower gear ratio. Note these gears will replace the 4.56 gears that are currently installed in my 1969 Trans Am. My goal is to return the car to its original condition, and because of the rarity of the car it will not be driven too much. I would like to kindly request your opinion on some questions I have regarding my recent purchase.

Attached are pictures of the gears. Some of the particles that are on the gears are small bits of styrofoam. My questions are:
1) In your opinion, are the gears in good enough shape to be re-used? I do see some slight scuffing on the gears.
2) The threaded shaft on the pinion appears to have suffered numerous hammer blows and some of the threads are damaged. I understand that the threads may be able to be cleaned up by grinding away some of the damage on the end of the shaft. Do you agree?
3) Any additional comments are welcome

Thank you for your time and assistance.

J. Petraglia

ok, good to see you using the site. Glad we can help- Happy Holidays to you and yours.
Well lets start with the easy. The gear faces appear to look pretty good. Nice and seasoned and hardened well from many years of driving with gear oil at proper level etc..... No burn marks or uneven wear etc.
Another test is the finger nail test...If you can run your finger across the face of teeth and feel high or low depth from going in and out of the mesh pattern then the gear is worn and likely not good for anything noise free.
Top edges of the gears next...It you feel sharp edges flashing pushed over metal to make a sharp edge...Gears were worn or bearing failer happened.
(PLEASE BE CAREFUL RUNNING YOUR FINGERS ACROSS THE TEETH OF A RING AND PINION AS YOU COULD CUT YOUR FINGER PRETTY BAD)
VISUAL FIRST BEFORE TOUCHING THAT WAY.

Next the thread...I think this is where your going to have your headache. You can see as you stated a hammer was used to remove the pinion from the housing....BAD!!
A pointed steal center punch into the shaft centering hole at the top of the thread (you can see pictured) is how to drive it out. Used with a 4# sledge to remove the pinion. THE larger the hammer the better...a few good taps and it will likely come out...IF you use a light hammer you could be pounding away and again do damage.
Anther method is the screw the old nut on the thread and pound on that...BUT sometimes could fail. depending how hard you have to hit.
brass can help too BUT we would not use brass again directly on the thread...USE the nut screwed on and the brass on the nut.

To clean that thread.... You will likely have to grind the first few thread away at about 45 degree and try to get a die to chase the threads. THESE are not easy to find...likely you will need to get one on line store. I think it is a 7/8 14 thread count.... that is a 8.5 gears will be the same for a 7.5 and the BOP 8.2 rears.
CHEVY 8.2 and 12 bolt will be 7/8 size with a 16 pitch thread.
YES, THEY ARE DIFFERENT!!!

if you do not have a chase / die keep grinding till you can get the nut to thread. ---you can try thread files...that is long and tedious process...but can be done if you have the patients.
Jim