Hey guys, my 2005 GT seems to be leaking gear oil from the differential. I noticed a small pool of oil on the ground under the rear axle when I last took the car out, It sits 90% of the time. it had sat for a full week between drives I figured maybe it was leaking from the cover so I tossed cardboard under it to see where the leak was. I jacked it up this morning and discovered that the front part of the pumpkin (facing the nose of the car) had gear oil on it, so its making me think that the pinion seal is leaking.

has this happened to anyone else before? Ive never worked on a rear end before so I am not knowledgeable on the subject. its not gushing fluid out, in fact when I cleaned up the leak off my garage floor the small puddle was only maybe 3 inches around, after the car sat for a week. is the leak due to the car just sitting around? can the outer pinion seal be replaced without taking the whole rear apart? or should I just find a good shop to fix everything? I dont want to screw up my car by doing it myself. whats the average cost for such job? I figure while its out I'll have 3:73s put in and maybe have the traction loc rebuilt with the carbon fiber clutches.

I should not that the car only has 75,000 miles on it. It is lowered, would the different pinion angle tear it up like that?

 

I had the same thing happen on my '05 GT. Took it to Ford. Don't recall the price tag. Didn't drive it very much that year, only a couple thousand miles. Ford said there is no rime or reason, just happened. They didn't say they have a lot of them. I do recall they knocked me up for a "discovery" that the seal was the problem, but, I have and had a mechanical Insurance policy that handled most of the cost.

 

Mine is weeping right now. Most places will replace the pinion seal without taking the rear end apart, so it isn't much money. If you drive on a dirt road, then your vent tube on top of the axle maybe blocked, which is why mine started leaking out the pinion.

 

Depends on the shop, and if you provide the parts or they do. When someone provides me with all the parts, the cost would be $300-$400.

But since you are thinking about changing gears, that is the perfect time to do it, get it all fixed at once

 

This happens particularly fast if you have lowered the car. The pinion angle, even on 2 piece CV jointed drive shafts can cause premature wear on it (as I had). Unfortunately, when the shop redid mine, they tightened the old crush collar too much and my car felt like it could barely move out of its on way. Too kit back and now my gears whine... Have driven like that for a year now... Haven't had the time to drop it off at a different shop. If you're going to do gears, then replace the seals, put new bearing races in and shim/backlash accordingly. While you have the cover off, replace the rear diff cover with a cooler looking one

 

thanks guys. Im going to be providing all the parts, figure since its got a bunch of miles on it, I will be having everything done once and done right.

next item on the mod list will be an adjustable upper control arm to set the pinon angle right.

 

I just had my seal replaced last week, had the same exact problem. It was an easy fix and they didn't have to take it all apart, just unbolt the driveshaft. I would also recommend not providing the parts or gears if your doing an install at the same time. The shop that did mine installed them wrong the first time around, went for a test drive and straight back in the bay. I guess if a shop installs your gears wrong they will replace them if there respectable, however can always come up with the "your gears were faulty" excuse.. Who knows, but free shipping as well if they provide them haha. Something to think about