SpartaPerformance

Um...no. I've never heard of pinion angle change causing diff problems, thats absolute bogus. If you use that vehicle to car pool 4 adults every day then your static pinion angle changes, that bearing is designed to take a lot more force then a pinion angle change. I've had car lowered for 33,000 miles and no leaks of worn bearings. Pay the 1hr diag fee take car to another dealership. When they warranty it submit both bills to Ford of reimbursement of diag fee from first dealer.

dkarthik

Thanks for the input everybody, just wanted to update to let you know I did manage to get it fixed under warranty, but the service advisor assured me he would not do it again and that this time was an exception. He also did not put any mention of the mods in the aftermarket mods in the Ford system (or so he says). Hopefully I won't have another bearing failure or any other diff issues in the near future. . So as a PSA, please take off any suspension mods before taking it in to a dealer to get warranty diff work. Once again, Thank you to everyone who took the time to reply.

JIM5.0

Your dealer was really really cool. He did you a huge favor; you owe that guy a drink at the very minimum.

Granted, I agree that only a 1in drop is still within design specs of the pinion angle due to the operating range the pinion must endure such as going over normal road bumps, carrying passengers, or when enduring chassis squat during acceleration, but they could have also argued that the 1in drop also increased the operating angle range beyond design specs.

In the end, those guys want to keep your business; they treated you above and beyond what is right; you owe them by treating them right in return.

I'm not trying to tell you what to do; I'm just voicing my thoughts on the matter.

tbear853

I've read a lot of posts about leaking pinion seals in the Mustang's 8.8 rear ... and our 2008 was always showing drops of lube hanging under the differential snout and it was obvious that it was from the pinion seal. I also noticed a slight hiss as pressure released when I was removing the fill plug to check level .... and it always started oozing out which tells me it was over filled.

Mine is out of warranty so I bought a new seal to replace it ..... but before doing so, I tried a change in vents to something more inline with what's under my several other Ford vehicles that don't leak. Stock Mustang rear vent has a rubber disc under slight spring pressure inside the vent's loose cap. It's a small hole in the vent, so it will take more psi to open the check valve than you might think.

I made a vent that attaches a hose that has a loop and is then routed inside the frame so no water ingestion .... but there's no restriction in the new vent. I used a brass fitting with a 3/8" hose barb on one end, turned other end down to tap it to fit the threads in the axle tube (7/16-20 sounds right). Clamped a short hose to it and a 3/8" copper tube with a tight U-curve in it, and then ran a piece of 3/8" hose from there down into a frame hole.

Not a drop of rear axle lube seen leaking since, the housing is now dry on the outside where there once was always lube hanging on.