diffo gonna take a crap? you decide.

[1985bmw325e]

well, after changing out the fluid of my diffo hoping to see if the whining/droning noise in the rear goes away, the noise still is there. Now, i've done a lot of research on this website as to what fucking noise it could be, but i'd like to hear what you guys have to say. This noise i believe has gotten louder after i changed the fluid out....maybe it's just my mind playing tricks.

Could it be wheel bearings?

Not sure if it can...noise does not change when i turn left or right....the noise is pretty consistent. Noise does not have to do with engine speed just to let you know.

half-shafts? not sure neither. CV joints? not sure neither


I have a feeling it's the differential. God knows how many miles are on it.

One thing i need to mention, to see if it is of any concerns or not.

My car is LSD equipped, 2.93 to be exact. When i jacked my car up, i turned one wheel to observe the other wheel spin the opposite way. However, the other wheel would only turn if I were to spin the wheel gently. If i were to spin it faster and sporadically, the other wheel would not turn at all. But if i were to gently and slowly turn the wheel, the other side will somehow catch on and then start turning the opposite way.

Perhaps that could be a problem?

[BMWM5LOVER]

Unless I am reading this wrong, you don't have an LSD, or it's broken.

[1985bmw325e]

I do have LSD, i even checked the diffo to make sure. I guess it is broken.

[asubimmer]

if the opposite wheel does not spin OR spins the opposite way you DO NOT have a lsd. Also lsd's have a s stamped on them.

[1985bmw325e]

I just want to diagnose this problem. Not to argue whether i have LSD or not. So i'm sorry for throwing that info in.

[asubimmer]

diffs whine. A LOT of them do. does the whine go away at the higher rpm's?

[DaN]

At what speed does the noise start?
Could be wheel bearings, I thought my diff was whining, but it was just a wheel bearing.

Jack up the rear, start it up, shift through gears and get the wheels up to speed with a helper. Listen from side to side, and at the diff, determine the source of the noise.
I also like to support the rear suspension under the shock bolts. This way the wheels are at normal compression with the weight on the springs. It may or may not put less stress on the cv axles.

[wastedincome]

I seem to have a "whine" to from the rear of my 92 318 vert' w/ LSD4:27
I also changed the fluid... Almost seemed louder for a day but seemed to calm down a bit....

I allready picked up a pair of rear wheel bearings as, my first thought was bearings but the rear end fluid was a easier, needed and a maintance item anyhow so I did that first....

I'm waiting for weather and time to do the wheel bearings ASAP. I'll try to let you know how that results w/ my "whine"

Another thing I was considering is the rear end's "out-put" shaft bearings.

[1985bmw325e]

diffs whine. A LOT of them do. does the whine go away at the higher rpm's?

no, the whine doesn't go away. Actually, when i reach higher RPMs, another prominent sounds comes in, sounds like a howling noise simulatenously happening with the whining/droning. That howling noise is at it's loudest at 3k in 3rd gear, then the howling sound is less loud in 4th @ 3k.

The whining/droning sound resembles that of an airplane getting ready to take off. that "EEEEEE" sound.


Dan, the sound starts to begin probably above 30 mph.

My friend also told me that if it is my wheel bearings, i would be able to move my wheels left to right (while suspended in the air). He sed i'm able to wiggle it a little bit in order to tell if my wheel bears are messed up. Is that true?

[DaN]

no, the whine doesn't go away. Actually, when i reach higher RPMs, another prominent sounds comes in, sounds like a howling noise simulatenously happening with the whining/droning. That howling noise is at it's loudest at 3k in 3rd gear, then the howling sound is less loud in 4th @ 3k.

The whining/droning sound resembles that of an airplane getting ready to take off. that "EEEEEE" sound.


Dan, the sound starts to begin probably above 30 mph.

My friend also told me that if it is my wheel bearings, i would be able to move my wheels left to right (while suspended in the air). He sed i'm able to wiggle it a little bit in order to tell if my wheel bears are messed up. Is that true?

That sometimes is true, but not always. I've had bad bearings that didn't show any play.

[1985bmw325e]

That sometimes is true, but not always. I've had bad bearings that didn't show any play.

hmmm........ I'm thinking it is my differential :-/