s2000amuse

Hey guys...

I had the diff. oil changed around 10000km if I remember correctly.......that same day I had espelir spring installed and wheels changed...by the way I used Motul 75W90.......so that same nite I can hear this grind..rolling...ooonnning kind of noise during slow speed sharp 90 degress turn (say coming out from driveway or coming out from a parking space)........ (hard to pinpoint whether it was front or back)...Had all installaion checked numerous times...spring..wheels etc.. and couldn't figured out what went wrong...

After a few thousand kms now...I have decided (really was out of the blue) to change to Valvoline synblend 75W90....the noise disappeared instantly and couldn't get the noise back at all no matter how I turn

What could have happened...thought Motul is a reputable oil....could I have damaged something with the stupid Motul oil??

Many thanks guys!!!!!!!!

Kel

Isn't Motul 75w-90 a transmission oil?

WalkingDrunken

Motul 75W90 is not tranny fluid. As long as it is 75W90 it should work in the diff I don't know what happened in your case.

Kwyjibo

i put some motul in my WRX and it was awesome....you sure it was filled correctly?

s2000amuse

saw him pumped the whole thing in and it was starting to drip and then he sealed off with the drain plug....don't thing the filling oil part had any problems......

xviper

It can be. Motul markets a 75W90 gear oil that is GL-4 rated and can be used in a manual transmision. I'm just not sure if it can be used in an S2000 tranny. Motul also has a GL-5 rated gear oil of the same viscosity. This is what should have been put into the rear diff. If it wasn't rated GL-5, then some damage to the LSD may have occured. Just because it's a 75W90 rating does NOT mean it can be used in our rear diffs.

GrimReaper

Not sure which Motul 75w90 you used, but apparently some of them are not to be used with limited slip systems (Motylgear 75w90)

chris_barry

The Motul may not have had the additives required for a LSD which would have made the diff creak on sharp turns. Oil companies like Redline sell "non slip" oils that dont have these additives, and also sell a separate LSD additive that allows you to tune the LSD action by how much additive you add to the oil. The S2K diff is a torsen style so doesnt have clutch plates, It does rely on side thrusts on the work gears and has some small bronze friction plates for preload so it could still make noise with a non LSD treated oil.

s2000amuse

thanks guys! I checked and it was Motul Gear 300 75W90....GL4 and GL5 rated.....so the oil is correct then right?

xviper

With all the information given so far, I believe you used the correct fluid originally. Why you got those odd noises, is beyond me. The only thing I can think of is that Motul produced a fluid that could be rated both GL-4 and GL-5. To make is usable in transmissions, they may have had to alter the characteristics of it as a diff fluid just enough that it didn't perform up to spec in the diff. Remember that a good diff fluid has high sulfer content, while a high sulfer content would be detrimental to our trannies.

As a side note, keep in mind that we don't have clutch packs in our LSD. Friction Modifiers, although they won't harm anything, won't do anything for our diffs, either.