Irishfan1

I just bought a 98 Z-28 6-speed with 4.10s. There is a very high pitched hum coming from the rear-end, only when you are giving it gas at any speed. Any ideas where to start?

killagt

iTrader: (3)

Change the gear oil. did you preview owner tell you what kind of gear brand he install ? most after market gear is noise, some noise then other.

Camaro Junky

Could be time to give Bob or Jaws a call on some rear love.

Irishfan1

I am going to change the fluid and see if that helps. Thanks. What size is the stock rear-end in a 98 z

Camaro Junky

Gear size?

99_Z_155

iTrader: (7)

I think the most common size is 3.42, but you need to look at the RPO list inside of your door for the "G" codes and that will tell you what it was built with. for instance "G80" means you had positraction. GT4 is like a 4.10 i belive, and so on. you can look those codes up online easily. if you want to PM me your VIN number, i can tell you any option you had from the factory.

Jawsgear

iTrader: (2)

Does the noise go up or down with acceleration? If the gears have been changed it is possible it is gear whine. Pull the cover and find out what ratio it is, the door tag tells you nothing if it has been changed before.

Jeff

Irishfan1

The gears where changed to 4.10s ive been told by the previous owner but he really had no clue. The noise gets louder and more of a high pitch the faster you go. Do all aftermarket gears make a loud noise?

Jawsgear

iTrader: (2)

Sounds like bearing and gear noise actually. Let me know if you need any thing.

Jeff

Irishfan1

what size rear-end is factory in a 98 z28? I know the gears were 3.42.

Camaro Junky

I think there is a code on the door. Just do a search and confirm.