rear end q.

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Aug 24, 2008 | 11:04 PM

DJPRacer58

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From: Sparta NJ

rear end q.

i got a 99 f150 lariat 5.4L extended cab wit a 3.73 LS rear and the limited slip stopped locking up on pavement. in dirt and gravel it still works but only 1 tire spins on pavement. it drives fine under normal conditions but the last couple of burnouts i did i noticed it. anyone know why this is happening?

thanks
derek

Aug 25, 2008 | 06:06 AM

torkum

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From: Mount Juliet, TN

The problem is too many burnouts

Pull the cover off and see whats going on.

Aug 25, 2008 | 04:32 PM

DJPRacer58

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From: Sparta NJ

thanks, where should i start looking at. theres a lot of small parts in that pic.

Aug 25, 2008 | 04:44 PM

Ron W.

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From: Stockton Ca.

For some reason Fords "limited slip" now uses steel and friction plates much like your automatic transmission, odds are your friction plates are "FUBAR".
Check the aftermarket and see if you can come up with an all steel set up, it'll live longer. The all steel "Detroit Locker" in my 75 GMC 4X4 never failed.

Aug 27, 2008 | 03:43 PM

DJPRacer58

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From: Sparta NJ

thanks, that sounds like it might be the problem. i got to look at it. i was looking online about the detroit locker and saw they make a limited slip diff called a detroit true track. i only problem is i cant find where to buy them for the 9.75rg

Aug 27, 2008 | 04:25 PM

Parts Guy Wyatt

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From: Seattle

Have You Changed The Gear Lube In The Differential (rear End) Lately Or At All? You Should Change It Periodically (60k Or So). If You Haven't, I Would Do That First. Use 75w140 Synthetic Gl5 Rated Gear Lube And Be Sure That You Add Abottle Of Motorcraft Xl3 Fricyion Modifier (very Important). If You Are Still Having The Same Problem After Changing The Gear Lube You Will Probably Need To Fix The Internals. Good Luck, Dan. 1964 Ranchero 302 T10 4speed 8" Rear End.

Aug 27, 2008 | 07:47 PM

DJPRacer58

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From: Sparta NJ

i had it changed at 110k, it now has 147k. it was done at an express lube when i first got the truck. would they have used that motorcraft stuff u were talking about?