carolinatim

My 2000 F150 5.4 with a limited slip rear end has a shudder when starting off and turning, doesn't seem to do it when starting in a straight line. I thought it was in the transmission but now I think it might be in the rear end. I have read about the 2004 having a TSB on the clutch pack, maybe this is my problem also? The rear is a 3.55 LS

kaboom10

You can start with just adding a bottle of modifier to see if that stops it. It's that or change the fluid to the proper weight of Royal Purple lube. I even found by replacing the rear shocks it helped stop it from chattering going around corners. I replaced the stock LS carrier with a TruTrac when I changed rear gears. Made a world of difference.

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02 F-150 FX4 w/Baer rotors,carbon kevlar pads,SS lines,remote coolers/filters. IAS shocks,LiveWire tuned by me.

67roadwhale

My 2001 f-150 has the same rear in it. I just had the right side rear axle replaced. My mechanic says this is a common problem with these trucks. Ford wanted almost $400 for a replacement but you can find them cheaper.

f1fifty

I have same issue with my 1999 F150 5.4. I took it into Ford dealership first year I bought it and they said they couldn't tell for sure so they replaced rear end under warranty- It's done the same thing ever since! I don't think its a problem. I now have 315,000 miles on it.

TNGlen

Notice this is an old thread. Hopefully will get some updates. I have the problem in my 01. I noticed that it started after changing the fluid. I have since been told that these rear ends required Ford Brand rear end fluid with the Ford modifier. Anyone else hear this?

kaboom10

Friction modifiers are required or noise occurs. I used full synthetic and didn't need it then. Using a full syn allows longer intervals for draining and provides maximum protection.

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02 F-150 FX4 w/Baer rotors,carbon kevlar pads,SS lines,remote coolers/filters. IAS shocks,LiveWire tuned by me.

Bert

If it's a limited slip, you'll need the friction modifier additive.

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Bert

kaboom10

If it's a stock Ford unit it does. I had a TruTrac put in when the gear ratio was changed. No more chattering around corners.

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02 F-150 FX4 w/Baer rotors,carbon kevlar pads,SS lines,remote coolers/filters. IAS shocks,LiveWire tuned by me.