My 2001 Supercrew 4wd 3:55 limited slip with 40,000 miles has just started a rear end whine when starting out till around 45 mph what is the fix? is there any TSB's for the rears? thanks Dan

 

My '01 made a slight whining noise at around 45 mph (25K miles). The buzz back then is that it was due to clutch material.


Has it ever been under water (boat ramp, 4 wheel drive)? I would pull the cover and inspect it, wipe it down, cover it back up if all looks good, (1) bottle of Lucas Oil Stabilizer, 4 oz. MC Friction Modifier, and top off with MC 75W140 gear oil.

Drive it a few hundred miles to see if the whine goes away or decreases.

James

 

Around 33,000 I replaced the rear end cover it rusted out. Noticied it was seeping oil a very little with a new ford Cover and ford oil 75w140 with the friction modifier the rear has never been under water? so the oil is still brand new Will the lucas oil quiet it down? thanks for your help James. Dan

 

Dan,

Yes, the Lucas Oil Additive will better lubricate the components which in turn will lower the intensity of the whine by coating the metal. How much? It depends on if there is a severely worn pinion bearing, spider gears, and so on... Adding one bottle of Lucas to the rear-end of my '94 F150 Lightning (138K miles) helped control the whine I was encountering.

Friction Modifer is a High Lubricity additive to help keep wear down on the clutches, bearings, etc. in a posi/LS rear-end.

Do you notice any vibration or clicking coming from the rear wheels in a sharp turn?

James