Hey Guys,
I just put in a used set of 3.73'sgears that had less than 500 miles on them. I went from 2.73's to 3.73. Anyway, I put them in and there is little (nothing to worry about at all)howl on acceleration.
What is troubling me is that upon deacceleration between 45- 25 mph, a loud howl comes in. As soon as I put load back on the howling goes away. At the mentioned mph, the howling is very noticeable, almost embarrasing.

Any of you that have changed your gears, how does your car('s gears) sound?
Does used gears have any bearing on this?
thanks for your help.

 

Not set up correctly either pinion depth or backlash, most likely backlash. You want beetween .008 and .012 the closer to .012 the quieter it will be but even perfect the gm 7.5 is the loudest rear I have ever worked with. They are usually quiet from the factory but as soon as you break the seal they all seem to make some noise. I have heard the same from a lot of other mechanic's as well. OOps, didn't notice they were used, they could be junk.

 

i have the same howling problem only my gears are stock. I keep thinking my rear is going out but it never seems to slip or anything when i break the tires loose, but when im deccelerating it does get pretty loud, is it possible the rear is fine for now and thats just the way it is?

 

I just bought a camaro with 373s and it sounded terrible(winding).I had the rear end rebuilt and it still howls at about the same speed on deceleration and unloaded and my mechanicsays it is ok. Dont know what the lash is set at but it runs strong and i guess i am living with it.

 

the gears were probably at the wrong backlash and once rebuilt, even though it may be correct now, they will still whine. ive heard that once gears whine, they will never shut up even when correctly installed.