rear-end troubles

[turbofiend31]

I've been hearing a strange sound from the rear-end lately: doesn't sound like a typical ring and pinion whine, but definitely increases with speed (more of a low hum). The pinion seal was just replaced in May --when I looked at it again today, it looks like it's leaking again. Think I may have a bearing issue that may be causing the seal to wear prematurely? This is strange since the car has less than 17k miles. Any ideas?

I haven't had much experience with the 7.5 rear--all my other cars had the 8.8. Thinking it is pretty much the same though, other than the lower power and torque ratings.

[8T6 SVO]

Sometimes the axle bearings will make this noise - even on a low mile car. Maybe the tires making the noise?

Just a few suggestions.

[Kendal Coker]

Put some friction modifier in it before you change anything else. It is the cheepest way to start and on a low milage car that should be the fix. If not you can go further.

[Ford Builder]

See if you can put the car on jack stands run the car put it thou its gears not to fast it should tell you if its the bearings .If the rear end gone down on fluid for a time It will take out bearings .Note setting for long period of time moisture will set in the bearings. Hope that helps you out.

[turbofiend31]

Sometimes the axle bearings will make this noise - even on a low mile car. Maybe the tires making the noise?

Just a few suggestions.

I thought at first it was the tires...unfortunately it appears to be the carrier bearing: I had my friend put it up on his lift and we ran it through the gears with a stethoscope. Years of sitting and moisture may have caused the premature failure. I know it is isn't a lack of friction modifier as I just replaced the rear-end fluid and added it several months ago.

Unfortunately, I also found a slow leak from the tail cone of the tranny while it was on the lift. In order to seal it, the tranny will need to be pulled. Looks like I will have some work ahead...

[Pat_in_L.A.]

The tranny doesn't need to come out for that.

[Ford Builder]

Glade Its not that serious .Thats easy fix Its better that if did not happen at all..

[SVOeric]

Unfortunately, I also found a slow leak from the tail cone of the tranny while it was on the lift. In order to seal it, the tranny will need to be pulled. Looks like I will have some work ahead...

a $2 seal, and 10 minutes work. longer removing the drive shaft than anything else.

[turbofiend31]

Thanks all for the info: it was hard to see up where the leak originated at the tranny-I could only tell it was from the tail cone. I'm glad I don't have to pull it. Gonna need some help pulling the driveshaft...

[tbrody]

Not completely surprising

I too have a low mileage 27k 85 car that has obviously sat for long periods over it's lifetime. First the rear brakes drivers side froze up replaced the brakes, and noticed extraplay in the rear axle and one side worn more than the other, this led to the discovery of bad posi clutch packs, dried out over the years and wore, when checking that out, yes it was bad found pinion seal leaking a bit, plan to replace that and find bearing bad, decide to replace all the bearing while in there, and the royal purple fluid. So much for the low mileage car, I am going to drive it from time to time sitting is NO GOOD. Good Luck! I feel your pain.