Whine from rear axle? (03 Tacoma)

Hi all,

When I am coasting in reverse or forward at low speed e.g. 5 mph, I am hearing a whine that seems to be coming from the rear axle.

Usually it happens just after I have shifted OUT of gear (it’s a manual transmission).

I uploaded the sound as a WAV file to here:
(Note! I recommend that you disable flash before going to this URL)
http://www.zshare.net/audio/94240250b99caa78/

When I speed up the whine just rises in pitch and it’s making my ears ring.

Does anybody know what that sound might be? Maybe I just need some “axle grease” or something?

Thanks.

Have you ever checked/changed the rear differential oil?

I haven’t but I’m not a mechanic.
I just had this truck inspected and it passed, but I suppose it’s possible they forgot to check that.
The sound actually started shortly after that inspection.

Do you do any towing with the Tacoma? Toyota recommends frequent changes of gear oil in differentials of vehicles used for towing. Even without towing you should replace the differential gear oil every 30K miles IMHO. Get the gear oil changed now and see if it helps. If it doesn’t help it might be too late for your differential and there could be some gear and/or bearing damage.

There are some other possibles, like a bad wheel bearing so start with the gear oil change and troubleshoot as needed after that.

I haven’t ever used this truck for any hauling or towing, if that helps.
It’s the lowest-end model. It doesn’t even have 4x4.