I installed a used rear end. Junkyard said it's a 2.73 out of a 91 Camaro with 110,000 miles on it that they've had since the mid 90s. My speedometer is now about 5mph less (in the 20-40mph range) than I'm actually going, and I didn't check the gear ratio when I changed the gasket. So either I previously had something better than 2.73s with the correct speedo gears, or they were wrong about the gear ratio. There was no metal shavings in the pumpkin, and the pinion and axles seemed to spin fine with no play.

Anyway, I also installed lower control arms, adjustable panhard bar, stock Moog springs, stock iroc rims, and all new brakes in the back and front. Did the front wheel bearings too.

When I first drove the car again, I did hear a vibration, not sure if it's the same one, but it sounded similar. However the drums/shoes were not properly adjusted and were barely working. After I adjusted the rear brakes, the noise went away. I drove it a few times to make sure, and it was fine.

Then I went to the tire shop to get new tires, and now I hear a vibration again. Constantly around 15-20mph. (around 10-15mph on the speedo). It's not there at highway speeds or any other speeds besides that. Sounds like wheel speed (wubawubawuba) rather than a driveshaft thing (mmmmmmm).

It was a terrible shop and a terrible experience. They jumped my car by putting the black lead on first. Then they took off the red lead first. Two mistakes by two different people, on something so simple. They also told me they would use a torque wrench, but they didn't. They also took 2 guys and 2 hours to do it, but from what I saw, it looked like they were working on 3 cars at once, and were leaving mine sitting for the majority of the time. It still doesn't explain why it took so long. I'm not sure if it's something they did, or if the noise just started appearing now.

Also I forgot to put the stock wheel spacers back on the rear. I'm using brand new drums with the stock aluminum iroc wheels. So from my research, it seems like I probably should put them back on, but it probably doesn't matter.

I'm hoping I just need to torque all the wheels and put the spacers back on the back, but do you guys think it might be something else? I am very limited on space and time right now, so it might be a few weeks before I can do any work on it.

You know, I forgot, there's also a popping sound when I brake hard in the front now. So hopefully the problem is just due to them over-torquing my wheels with an impact.

 

More about OE spacers below:

https://www.thirdgen.org/forums/tran...-10-bolts.html

JamesC

 

Yeah I read the sticky. I know it probably doesn't matter, but the new drums are iron and the wheels are aluminum. Plus they came on the car so might as well put them back on.

But yeah, probably has nothing too do with the vibration.

 

Well I torqued all the wheels down and put the spacers back on just for kicks. Still has the same vibration. It sounds like a rattle or wobble. 15-20mph is the only speed it happens at. And it still drives fine and perfectly straight at that speed, there's no wandering or anything. Highway driving is fine with no noises

 

How do you hear a vibration?
Jack up & support the rear end, have a helper put it in gear till you hear the noise so you can pinpoint which side it's on.

 

I'd be checking for a bent axle. Very very common thing; amazingly easy to have happen from hitting a curb or something. You'd be surprised how little of a boink on a curb wil bend one.

Put the rear end up on jack stands, under the axle tubes. (not the shock brackets, not the control arms, not ANYTHING ELSE besides the axle tubes) Start the engine, put it in gear. Watch the wheels rotate. If either one seems to wobble, swap them. If the wobble moves to the other side, it's a bent wheel. If the wobble stays on the same side, it's a bent axle.

Probably not anything related to lug nut torque, spacers, drum material, or any of the rest of that.