diff whine?

[87-325ic]

My differential has been making alot of noise lately. it sounds like my rear seats are out but they arent.

is it time to change my gear oil again? its redline synthetic in there, but it was like 3-4 years ago that i changed it and its recently started making that loud hum.

will cold weather and older oil cause this or what?

thanks

[Mike325]

The oil and cold could cause the noise yes. I would change the oil to something that has some type of LSD conditioning in it, if you have an LSD. I think that redline stuff has it in it though. Does the noise happen more or less when you turn to the right or left? Does it get better as your car warms up? Any vibrations?

[UDelaware30]

have you replaced the diff mount to poly? When it is cold, my diff makes some noise because of the 75d poly mount.

[TheB1G Lebowski]

make sure there is still fluid inside. Check the pinion seals and axle seals to see if they are leaking. If its making a whining noise already and increases with speed, its prob already done for. The bearings have more than likely already been damaged and need to be replaced. And as stated above if you have a LSD then you need some friction modifier to be added to the fluid as well.

[svn2002s]

+1 on some additive

[ieatpeople]

yup, my 87is droned like it needed a wheel bearing, and make funny noises on turns. changed the fluid, put the lsd additive in, no more noise.

[87-325ic]

the redline gear oil doesnt have the LSD additive? i thought it did..

its been a few years since i replaced it. it never really leaked before, im thinking its just the coldness. it seems to go away a little bit when warmer..

its not a vibration or anything, just an audible, speed related whine.

ill check the fluid level soon, but i may just replace the fluid.. its just such an annoying affair to go buy a pump. save the fluid, and then try to find someone to recycle/ take it.

[Wh33lhop]

There are two types of Redline diff fluid, the "LS" type has friction modifier additives and the "NS" type does not. (The friction modifiers are not your problem though, and you'd probably know if you didn't have any as the diff would chatter around corners)

It's possible that the seals were just old and the synthetic fluid seeped through them slowly. Check your fluid level.

My diff has always whined, for what it's worth. I'm not really worried, from what I understand it's pretty normal for the LSD units.

[T Verdier]

I don't know if this helps but my diff was fine when I chose to change the fluid , I put some aquatorque in it and months later I had less lock on my diff. it would act like an open diff every now and then. A year later now I pretty much have an open diff 80% time and an LSD the other 20% of the time, very unpredictable and annoying. It could have been a coincidence but with my next LSD I wount be adding anything but diff fluid.

[Wh33lhop]

I don't know if this helps but my diff was fine when I chose to change the fluid , I put some aquatorque in it and months later I had less lock on my diff. it would act like an open diff every now and then. A year later now I pretty much have an open diff 80% time and an LSD the other 20% of the time, very unpredictable and annoying. It could have been a coincidence but with my next LSD I wount be adding anything but diff fluid.

Is it an open at low speeds/sharp turns in first gear/donuts and an LSD otherwise (hard corners, second gear+)? Because there's an explanation for that.

[ck_taft325is]

I've had 5 LSD's and 2 of 5 whined a bit. I'll be putting Redline Diff. Fluid (LS additive) in my DD simply to prevent it from "worsening". Only one of the 5 really quieted down after flushing it out and replacing. 50/50 chance I imagine. I really do want to get a spare to rebuild just to say I have ;)

[T Verdier]

Is it an open at low speeds/sharp turns in first gear/donuts and an LSD otherwise (hard corners, second gear+)? Because there's an explanation for that.

Kinda.

Example: I'll drop the clutch and both wheels break loose and the back of the car starts to drift out, then it all of the sudden and jerkeley caught it self and spun only one wheel.

The other day on a drive I made a sharp turn and the inside wheel spun and the car barely went anywhere.

I think it's worn diff clutches

[87-325ic]

i should check my fluid, it hasnt been as noticeable since my fluid change, but the last few months it sounds kinda like i took my rear seat out, just a bit louder you know?

nothing bad sounding yet..

[Wh33lhop]

Kinda.

Example: I'll drop the clutch and both wheels break loose and the back of the car starts to drift out, then it all of the sudden and jerkeley caught it self and spun only one wheel.

The other day on a drive I made a sharp turn and the inside wheel spun and the car barely went anywhere.

I think it's worn diff clutches

It is, but try disconnecting your rear sway bar. Should help (unless you've got really stiff suspension and your rear sway is stock).

i should check my fluid, it hasnt been as noticeable since my fluid change, but the last few months it sounds kinda like i took my rear seat out, just a bit louder you know?

nothing bad sounding yet..

Go ahead and check your fluid.