Ok well was talkin to my boss about mustangs, and we where talkin about gear ratios and such.

Well I brought up about the rear gear box, because Ive noticed a small amount of oil leaking from the rear end of the mustang on my garage floor......the oil looks clean from what I inspected or what is dripping out looks clean like a amber color...well is it natural for it to leak???? its not leaking alot but i did find 3 drops of oil on the garage floor and I havnt drivent he mustang today. Did drive it yesterday....all i have done is the 3.73 gears.

Also when cruising at a set speed and my rpms are around 2k, theres a slight humming noise.....is that because of the 3.73 gears? My boss said the bearings maybe wearing out or need re-greasing?

 

it might be a bad install... if gears are installed poorly they tend to whine... and as for the leak you should check and see if the diff cover is tightened... I've seen that happen before lol.

 

Well I assume you mean the differential...

Leaking is never good...nor should you ignore it. Did you make sure your differential cover is tight? Or maybe the gasket is shot?

The "humming" you're noticing is from the 3.73 gears...whoever did the install job, didn't do it right and now you're stuck with the whine. Alot of people have it, it's just annoying. Try this...

-Loosen your differential cover, and put a drain pan underneath. Let the gear oil drain into the pan until it stops draining.
-Buy a new differential cover and gasket
-Take off the old cover, clean the edge of the differential with a razorblade to remove old gasket material and such.
-Put on the new gasket and cover
-Pump new gear oil into the fill plug until you can stick your finger in the fill plug and the level should be right up to the plug hole, not lower, and any higher, it should leak out.

That might stop the leak...it's a try.

BTW: In case you didn't already know, the fill plug is directly to the right of the driveshaft yoke on the front of the differential (side facing the motor and trans.) Use a bare3/8 Socket wrench to open the plug.

 

aight cool ill do that. thanks for the info....

if the 3.73 gear is a bad install will that cause any future problems? or is it typical for the 3.73 to whine like that.

 

Nope no problems that I'm aware of, just a really annoying whine that will always be biting your ***. [:@]

 

Well took it to the shop and the seals werent replaced when the 3.73 gears where installed so i had the gears installed with new oil. I had him over check the 373 and he said it looks good and he didnt see anything wrong.

 

sounds like a bad install all the way around, gears whine, and they cut have cut the pinion seal on the reinstall.