Is it a bad idea to install a used set of 3.73 gears into my car? The differential are the same size and they have only been on for about 30000 miles, so the wear is very minimal. All advice would be VERY helpful before i buy them. the guy is selling them for only $35 so its a good deal i think and he lives near me, so i can go look at them before i give him the money. thanks

 

If you can find out what the backlash was set at when they were in the car it would be very helpfull.This way you can set the gears to the same measurement and keep the same wear pattern,or close anyway.
I would be wary of buying used gears.They aren't that expensive to buy new.

 

Given the fact that a set of new gears can be had for under $200 and the amount of money it will cost to install them, I wouldn't ever consider installing used gears, even if they were free. I think most installers will probably refuse to install used gears as well.

 

No, I would never put used gears in my car either. Get new ones and while your at it, buy 4.10`s instead. You won`t regret it.

 

look at the teeth on the gears and see how they are, theres nothing wrong with used gears, my buddies 4.10s came out of a wrecked stang with 40k on them, cobra232's came out of an explorer with 150k on them, no problems