Rear end whine

[jb9281]

I have a 66 c10 and it has developed a rear end whine during acceleration. No noise while coasting. Any ideas what may be wrong. New 350 with new rebuilt 700r4, original rear end 12 bolt 3.73 gears. 600 miles on engine and trans, unknown on rear end, I have changed gear oil

[Wrenchbender Ret]

First grab the pinion yoke & check for any freeplay in the brgs. Pull the cover & check for any side to side play in the carrier assem. If you have any play in these you have worn brgs & need an o-haul.

[andyh1956]

Originally Posted by Wrenchbender Ret

First grab the pinion yoke & check for any freeplay in the brgs. Pull the cover & check for any side to side play in the carrier assem. If you have any play in these you have worn brgs & need an o-haul.

He's right. Take a big screwdriver & try to pry the ring gear / carrier assy up & side to side. Most likely it's the left side carrier brg. The pinion gear is always pushing the carrier assy to the left going forward & the left brg wears out.

[jchav62]

What does it mean when it whines only while coasting?

[Clyde65]

Bearings are bad, probably inner axle bearings.

I bet it whines all the time, you can only hear it when you let off

[jb9281]

OK,I jacked up truck and placed on jack stands. I started truck and let it idle in drive. I used the old screwdriver to the ear trick. I could hear a clicking noise on the drivers side axle bearing with and without the screwdriver to my ear. Passenger side was quiet. I checked pinion shaft and it was quiet. I pulled both axles out. Drivers side has 3 chipped out places on the axle. Passenger side has a bad seal groove. I can find no play in the ring and pinion. I looked into axle shafts and found a shim sliding out of place on the passenger side of the rear end where you shim the diff. used a long screwdriver to center it back in the tube. I could see a slight wear mark close to the splines where the shims were rubbing axle. What do you guys think about me replacing the axles and axle bearings first without rebuilding the diff now. Maybe the bad axle is all my noise?

[vince1]

I bought a repair bearing and shim kit from rockauto for mine and did the carrier bearings. I was able to slide in a .005" shim. I don't hear the noise anymore. If you just want to do carrier bearings the cup and bearing P/N is BR36.

Before this last repair I had the axles out and they were all chewed up on the bearing surfaces like you describe. They make repair bearings for them where the bearing rides on the axle further outward. You shouldn't need to buy new axles when using the repair bearing. I think Rockauto also sells that one.

[andyh1956]

If you see thin "Shims" on your rear then someone has been into it before. The rear came factory with selective fit iron spacers, & they break! Know that to "Properly" set side bearing preload the axle housing should be "Spread" about .015" -.020" when sliding the carrier in & out. What does the wear pattern look like on your gear teeth?

[vince1]

If you are asking me Andy, i think the wear pattern was OK. Yes there were only single thick spacers on each side but they were loose. Ideally it should have a proper overhaul instead of just replacing bearings. Some day maybe I'll learn how to do it. When I got this thing it was filled full of some gritty material, maybe to keep the noise down. Kind of a rip off for $300 but I've got it cleaned out and don't think I am hurting anything now by continuing to drive it. I don't think the.005 shim I managed to get in is going to make any difference in the wear pattern, and it still has back lash.

I don't know if this info helps JB with his whining noise but just to say I have changed bearings before without any changes to shims and gotten more life out of them.

[cg285]

technically you need a case spreader but i've done lots of them over the years and never needed one - and there is a simple trick to reinstalling the cast spacers without breaking them.
there are other units that are virtually impossible without a spreader tho'.

[andyh1956]

ok then! If it's that loose the carrier may just fall out when you take the caps off!
Yeah those spacers are tough, they don't take much beating on (Don't ask how I know...)
Any way good luck with it, if it's noisy just turn that Lynyrd Skynyrd cd up some more!

[cg285]

Originally Posted by andyh1956

ok then! If it's that loose the carrier may just fall out when you take the caps off!
Yeah those spacers are tough, they don't take much beating on (Don't ask how I know...)

sometimes they do fall out.

there is a technique to beating on them without breakage. i invented it years ago.

[jb9281]

Got my new axles and bearings today. Now I have to wait on the new brake parts I ordered. Maybe I can start installing the new parts next week.

[jb9281]

Got the new brake parts installed. Installed new axle bearings and seals. Then I installed new axles. Drivers side brake drum went on fine. Tried to install passenger side and drum would not slide onto the axle??? After further inspection found out the new axle bolt pattern was drilled incorrectly. Drum would not center on the axle center hub. Remove axle and removed lug studs. Drum would fit on hub, but the stud holes were off center. Called National Drivetrain and they are sending me a replacement axle. Now I have to wait a few days to find out if this fixes my rear end whine. If it does not I will order new ring and pinion and a new eaton posi to complete my rebuid.

[jb9281]

I got all my new parts installed today, the rear end has been completely rebuit with new gears, pinion,usa bearings, axels and axle bearings, and brakes. Maybe tommorrow I can can reinstall the rear end and go for a ride and see how she sounds and drives. hopefully no more whine.

[Captainfab]

Let us know how it goes.

[jb9281]

Just noticed the new rear drums do not have adjusting slots like my old drums have. Started looking on line and none of the new drums have slots. How do you adjust the brakes without this slot on the drum?

[Palf70Step]

I don't think they are made with the adjustment holes any more, least I never found any either. So, I used a drill and my dremel tool to cut in my own adjustment slots in the appropriate area as if the came with it. No issues and I used stock rubber brake plugs in the holes I made

[jb9281]

Thanks, I will try that. Rubber plugs came with my new hardware kit.

[Captainfab]

Don't the backing plates have a slot for adjusting the brakes?

[jb9281]

If they do they will have to be punched out. I will go see if they have the knock outs

[jb9281]

Just looked at backing plates. No holes or knock out location. Guess I will have to slot the drums.

[jb9281]

No more rear end noise. Maybe I need to eat some beans? Finally got the rear end rebuilt and installed and the brakes rebuilt. No more noise or whining. Thanks for everyones input.

[Palf70Step]

Glad to hear you got it right again.