Diff rebuild

[walterbunt]

I have a 97 Explorer 4.0L OHLC - VIN 1FMDU34E6VUB30406 - Have a noisy rear diff, think I should replace diff bearings and seal (I imagine crown wheel and pinion OK) BUT I cannot find any serial or diff axle no on vehicle, not on inside of any door pillars, the only numbers I can find are on the diff housing = 3L 7388 6L1 4 - S613CR , difficult to read, but I think this is right. Can anyone guide me as to which diff I have, to order bearings and wether I should also replace pinions etc. Thanks

 

[joecrna]

Ford 8.8 rear axle. The diff is a 3.73 Limited slip. Have you had the truck awhile. Fords 8.8 is known to whine a bit. Change the fluid and add some friction modifier. Drive her till she dies.

 

[IZwack]

First check for "play" in the pinion (search if you need more info). If there is play, tighten the pinion nut to specification and see if the whine goes away. If the noise doesnt go away, then the pinion is not in position anymore (worn bearings?) so the differential will probably need to be overhauled.

 

[walterbunt]

Thanks, I have changed the oil and put additive in diff, ran it for about 100 mile - no difference - does anybody think that if I only change bearings will it be OK or do I change crown and pinion ? didn't realise you can tighten pinion nut, where can I find specs for this. Thanks

 

[FORD SUV GUY]

The only decisive way Im aware of to verify the condition of the "ring"(crown?)and pinion gears. Is to remove to cover and do a visual inspection for wear and/or broken/chipped teeth. If they are in good condition then IMO they can be reused. As for a bearing set I used and rrecommend the "Yukon" bearing kit. It comes complete w/everything needed. And very good/easy to read instructions. Do a search on "8.8 rear differential rebuild" in this forum. This is how I found most IF NOT ALL the info I needed to SUCCESSFULLY rebuild my rear diff. Good luck n let us know how it goes!

 

[imp]

I have a 97 Explorer 4.0L OHLC - VIN 1FMDU34E6VUB30406 - Have a noisy rear diff, think I should replace diff bearings and seal (I imagine crown wheel and pinion OK) BUT I cannot find any serial or diff axle no on vehicle, not on inside of any door pillars, the only numbers I can find are on the diff housing = 3L 7388 6L1 4 - S613CR , difficult to read, but I think this is right. Can anyone guide me as to which diff I have, to order bearings and wether I should also replace pinions etc. Thanks

1. Certain the noise originates in the differential?
2. The axle is Ford Model 8.8. You do not need all kinds of identifiyers to buy bearings, etc. Without such info, the unit (IF it is determined to be the noise source), can be disassembled, parts problems isolated, then replaced using similar stuff. Bearings are all individually numbered. If GEAR SETS are to be replaced, RATIO must be maintained same.
3. Noise originating in the rear of the vehicle is not always differential-produced. Best to listen closely with parts in motion, wheels off the ground, to possibly save the expense and time of messing with a GOOD differential. imp

 

[rhauf]

does it whine under acceleration, or deceleration? is there a "sweet spot" where it gets quiet?

is the pinion wiggly? check that the pinion nut is tight (ive had them get loose)

stick your finger in the oil fill hole.. does the oil look normal or is it silvery? (silver gravy = replace everything)

jack it up and try lifting the rear tires up and down.. see if there is play in the wheel bearing (a tiny bit is normal)

if you take it apart, you can tell which bearings are good and bad, look at the race, if it has marks on it or looks warn, replace it.. if it looks new, it's fine.