I have a 98 F150 2WD, 4.2L manual. There is a whine or hum in the rear end. Actually I don't know where it is, but the faster I go the louder it gets. I've had it looked at, asked questions about it, and looked at myself (without taking it apart). I have been told that it is a bearing, don't know which one. I've been told it is the Ujoints. And I've been told it is the drive shaft center bearing support assembly, but I do not have one of those.
Bottom line, from looking at it the only thing I notice that seems to be out of place, or not like the rest, is the rear differential. Connecting the driveshaft centering socket yoke to the differential is wet looking. It is not dripping with oil and there is no spray pattern from oil, it is just very wet.
No I don't know the proper name for it and that is half my problem.
If any one can help me out, other than telling me to suck it up and go pay the five hundred to have done for me, I'd appreciate your help. Thanks.

 

Unfortunately the only way to find out what is really going on in there is to have the differential torn down and inspected. Most common is a pinion bearing making the noise but there could be more wrong also depending on how long it has been like that. If you are unable to properly do the repairs yourself then the only other option is to have a shop do it unless you have a friend that can and is willing to help you out.

 

My 97 F150 had the same problem.(8.8 differential)I took it to a differential shop and it was diagnosed as bad pinion bearings.After the tear down it was both pinion bearings and one carrier bearing.They rebuilt it going back with US Gears,Timken bearings and races,axle bearings and seals,a new carrier,and new spider gears.Total cost was over $1000!

 

o.O

man i just rebuild the 3rd member on my truck for the third and final time i hope.

8.8 detroit locker $600
timken bearings and cups (funny thing is its the same bearing for the inner wheel bearing on 67 broncos), new ring gear bolts all ran me a lil more than $100 for it all from ford. oh and a shim kit since ive had hard luck finding someone that has em.

i improved my rear end for less than you got hosed for.

 

I consider it an investment.BTW,I sold the truck a couple of weeks ago;I got $4500 cash! Now,who got hosed?

 

you imo... you fixed what bothered you not necessarily the guy who bought it. lol

i like my truck.

 

I liked the truck too.But I wanted a new truck.So,in order to sell it I had to make sure everything was in working order.Would you buy a truck with a defective differential?
And,I don't think I got hosed.Call around and get an estimate on what I had done to my differential.Its not cheap.

 

my price was $250 labor. parts was uh? 300-400?

 

I can see you are not a person that thinks rationally.I could say I paid $500 total and you would still have some kind of negative reply.If you think I got hosed,fine.....thats your opinion and you know what they say about opinions..hmm,maybe you are like opinions?