I bought some 3.73 gears from SLP. I bought these gears mainly because they claim quite operation. Is this true. The guy at the speed shop said that when you get up to 3.73 rear they'll make noise. Yet I heard gears only make noise when they aren't put in right or lined up correctly.
If these gears do make sound, is it because of the ratio or the install. Also what kind of sound do they make. I talked to a guy who had a fourth gen z28 convertable and he stepped up from a 2.73 to 3.73. He said the sound is droning and annoying. Is that because of the jump in ratio or the install?

 

Higher number ratio gears do tend to make somewhat more noise than lower number ones, because they have fewer teeth on the pinion. But, properly set up, 3.73s aren't particularly bad... they were stock in lots of cars for years, I've had Chevelle SSs, old Z28s etc. that came with them, and of course my 83 HO car.

If your bud used Richmond gears, that may be the answer right there. Those are designed for strength at the expense of smooth and quiet operation. It's a compromise: give up one to get the other.

 

Its the install. If he says its because of the ratio, then he's covering his butt cause he don't know how to install them. SLP sells GM gears, which is the quitest ones I know of. GM puts 3.73s and 4.10 gears in alot of the trucks and they are as quite as the 2.73s. I have replaced these gears and they have always been as quite as when they were installed at the factory.

On the other hand, I heard that Richmond gears are usually noisier, and this may be, since different manufacturers have different cutting techniques of the gear, but we were talking about GM gears (the $199 gears from SLP) and they are very quite. As a matter of fact, I have 3.42s from SLP in my car now

 

Did you jump up from 2.73's? If so, what kind of difference did it make in the SOTP and E.T.? And isn't like a special additive that you're supposed to put in the diff?

 

I didn't jump from 2.73's this guy I met did. He had like a 94-95 z28 convertable which he said came with 2.73s stock. He said that the gears made the car faster, but all he does is spin like crazy.

 

I origianaly went from 2.73s to 3.73s and it made a HUGE SOTP difference, but as I modded my car and got faster, the low end torque of the TPI plus 3.73s made it impossible to launch the car. I could break the tires loose at 20 MPH and my 60ft times sucked. I have since then stepped down to 3.42s and wheelspin is not as much of a problem any more.