Rear Diff Cover Leaking
- Thread starter Kris Gau
- Start date
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Bill Koonce
Active Member
Good question. I'm wondering about that too. I use a strong aluminum cover that has adjustable preload differential carrier bearing cap supports on my Mustang. Although the 8.8" is a pretty strong unit, if anybody can break a differential without even trying, it's me. 
These strength-adding covers (mine is from FRPP and says "SVT") don't work with Lincoln car IRS, T-Bird or IRS Cobra rear ends because those have a special load-bearing cover. But when I looked at the IRS on my '07 Sport Trac, it looked like it just might be possible to use a strength-adding cover on it. I haven't made actual measurements yet, but it would be sweet if the '07-'10 IRS ST accepted at least some 8.8" live axle covers.
If it is possible, there's no guarantee that the carrier caps are compatible with strength-adding covers. But if you can get a larger capacity cover that doesn't interfere with the anti-roll bar, that would be better than stock. More fluid means that the fluid will run cooler most of the time, which is a Good Thing.
Strengthening the bearing caps will help prevent deflection when the ABS/TCS/RCS/YCS suddenly slams on one brake pad to correct some minor instability. Mine has kicked in with a loud, scary thunk when I turn off of asphalt onto dirt and gravel roads that aren't level with the paved road. The Advance Trac RSC system interprets the roll and yaw as something more serious than it is. Doing this over and over is bound to strain the whole rear end.
Anybody else know if aftermarket live axle covers fit? I don't relish having to take the measurements myself, without a lift.
These strength-adding covers (mine is from FRPP and says "SVT") don't work with Lincoln car IRS, T-Bird or IRS Cobra rear ends because those have a special load-bearing cover. But when I looked at the IRS on my '07 Sport Trac, it looked like it just might be possible to use a strength-adding cover on it. I haven't made actual measurements yet, but it would be sweet if the '07-'10 IRS ST accepted at least some 8.8" live axle covers.
If it is possible, there's no guarantee that the carrier caps are compatible with strength-adding covers. But if you can get a larger capacity cover that doesn't interfere with the anti-roll bar, that would be better than stock. More fluid means that the fluid will run cooler most of the time, which is a Good Thing.
Strengthening the bearing caps will help prevent deflection when the ABS/TCS/RCS/YCS suddenly slams on one brake pad to correct some minor instability. Mine has kicked in with a loud, scary thunk when I turn off of asphalt onto dirt and gravel roads that aren't level with the paved road. The Advance Trac RSC system interprets the roll and yaw as something more serious than it is. Doing this over and over is bound to strain the whole rear end.
Anybody else know if aftermarket live axle covers fit? I don't relish having to take the measurements myself, without a lift.
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Chad Merry
Well-Known Member
You dont need a new cover just the gasket. Go to your local parts store, spend a couple bucks if that and replace it.
EddieS'04
In Memoriam 1950-2022
Never seen a cover rust out. Gasket or silicone yes.
scott degroot
Well-Known Member
Silicon only for the rear diff cover adn it shouldn't ever leak again
Johnny O
Well-Known Member
Lube Locker gasket. Idiot-proof and I'm an idiot. Any time I screw around with Permatex it'll leak.
Bill Koonce
Active Member
Lube Locker? Sounds like an adult toy store... :rofl:
Dom Carlino
Member
Yup it happened to my 04 also. The cover rusted through and was slowly bleeding out the diff fluid. NAPA< AUTOZONE and Advance auto all have a new cover for about 20 bucks. Just a plain steel replacement nothing fancy.
