New noisy LSD

[Ziggy]

Just fitted a 3.91 LSD, & it doesn't sound healthy at all
I'd always thought that diff noises were usually only when under load, but this one makes a kinda hissy whine that varies with speed rather than load.
Sounds kinda like a very noisy fuel pump! I thought it could have been something rubbing somewhere, but I've just had another look & I can't see any evidence of that...

Because it doesn't depend on load, I'd have suspected something else, but that'd be just too much of a coincidence really... It's supposedly just had a fluid change, & I bought it off a zoner that I'd trust not to sell a $hagged diff so I'm a bit confused tbh! Any ideas?

[thesaint]

from my experiance the slippers do whine uite a bit.

mine whines very loudly just how you described, will one day get around to having it looked at, but hey it stll works so no rush.

[Ziggy]

Cheers mate I've had loads of RWD cars, but somehow never one with LSD before so I'm not entirely sure what to expect! I've just checked the fluid level & that's fine...

[Templ8e30]

A healthy LSD should be silent.

The whine you describe sounds like the 3.64 open diff I had a while back, whined regardless of load and was related to road speed. The input shaft bearings were shot so I binned it and got another.

I'd look at getting it re-conditioned by a pro with new bearings and seals. Make sure they are quality bearings, the originals are Timken (the best) but SKF are almost as good. Cheap Jap crap bearings won't last long in there.

Cheers,

Iain T

[thesaint]

mine must be knackered then

[Karan]

hi mate that diff whined.... just the bearings but it was checked and the guy said bearings are ok

[fuzzy]

when i discover new noises i just turn the radio up a bit...problem solved.

[Dan318-is]

Ziggy,

have you driven for about twenty minutes then listened for the whine?

mine whines like a bitch from cold then is silent after 5 minutes driving. there is only a faint whine when i get it to lock up which isnt often

mine is leaking from the ouput seals though; well, seaping.

HTH

[bottlecapE30]

when i discover new noises i just turn the radio up a bit...problem solved.

That is how i do it till i have the $$$$$$ to fix it

[Brianmoooore]

If it makes this noise in a straight line, then it's nothing to due with the diff, LS or not, since the diff is just sitting there, spinning as a whole.
The problem must be with the crown wheel, pinion or their bearings.
Hissing whine is fairly common from E30 diff units and they go on happily in this condition for many tens of thousands of miles.

[Karan]

this was my old diff.... its the bearings trust me.... diff specialist aid he could change em for £300 but said it was not worth it as they would be fine

i guess u notice it more in a cabby

[Ziggy]

's cool then guys, Cheers - wasn't havin a go or anything Karan - just wanted to check it wasn't gonna blow up on me! I do like the way it drives now - can't believe the difference!

I'll get round to changing the bearing one day...