slight whine in rear end normal, SYN VS non SYN gear oil ? cold?

[Moretorque]

I noticed this morning in 30 degree weather my rear end had a slight whine when driving, I never really noticed it before. It is slight, is this normal? Could it be cold weather or the fact I changed the fluid using non synthetic gear oil? Is there a additive to help whine?

Just curious because I never really noticed it until this 30 degree day! Thankyou.

 

[Moretorque]

No help or thoughts on this? Thanks

 

[tbrumm]

I think the oil specified for the Sterling is 85W140. I would also run synthetic as that is my preference, but I don't think synthetic is required. If you put in lighter weight oil, that my be why you are hearing a little bit of noise now.

 

[Moretorque]

I think I may have made a mistake running what I did in the rear end, On my Honda Valkyrie I remember being told to get rid of the gear whine you need to run a good SYN. I did this and the gear whine was reduced dramatically. I think I should have known but the whine noise may have always been there?

 

[riotwarrior]

IIRC and could be wrong...

85-140 synthetic if you have a posi! You'll need to know if you have a Posi.

How many miles on the truck? Could just be that it's slightly worn and as such this will be the case as well.

 

[Moretorque]

I put 85 140 in it but I did not use SYN, the truck is a 2 wheel drive dually F 350 1994 T

 

[riotwarrior]

I put 85 140 in it but I did not use SYN, the truck is a 2 wheel drive dually F 350 1994 T

If it's a POSI or Limited Slip you should have synthetic if not then non syn ok but syn better...it's that simple

Look at the tag on the drivers door jamb it should have an axle code. Post what that code is here we can decipher ifn it's posi or open..

Likely a posi is my best WAG.

Al

Also as requested PLEASE FILL IN YOUR SIGNATURE go to settings on the top right of the screen, scroll down to edit signature on left side of page, click that link, then fill in your signature with all your truck information save it and your done!

 

[IDIDieselJohn]

These old rear ends use 80W90.



A whine in a rear end could be 2 things.

1 - it's low on oil
2 - theres to much backlash in the pinion gear from wear or abuse.

 

[Moretorque]

I just changed the fluid in rear, it did not need to be done because the fluid that came out was like crystal clear but how was I to know. It is full unless there is a leak. It's just a slight whine noticeable when there is no load on motor and the engine is running real quiet when cruising.

Thanks for your help.