Has anyone tried running a 85w140 diff oil to quieten down some diff whine caused by leader gears and ES urethane bushings . Stock weight is 80w90 Ive Heard of people running mt90 in there Diffs ive used a Nulon Diff and gearbox treatment additive and it didnt make much of a difference.. Diff only makes noise around 90 to 110 otherwise its generally silent, diff had all new bearings and seals when the leader gears where installed so i doubt there is a install issue
Richmond Gears include literature with the gear set recommending 85W-140 oil. Only an idiot would run MT90 in a Z32 diff fitted with Leader Gears. Redline Oils state that Shockproof Gear Oils are unsuitable for street applications, but what would they know. I recall when the Leader Gears were being installed by members on this forum a few were identifying diff whine. The whine would more than likely be attributed to how the diff was installed, as you know, some mechanics are better than others. I had Leader Gears installed by a company that specialises in diffs & there is no difference in noise between the OEM diff & the Leader Gears/Quaife unit. You could remove the rear cover on the diff & check the wear pattern on the gear teeth, or alternatively take the car to a diff specialist & see what they say.
Where? And what would you define as street use? In this case (a heavily modified car producing significantly more tq than stock and running a lower final drive) the heavy shockproof is within the specs outlined in the FSM but will offer significantly more gear protection and service life than a "regular" 75w90 or 80w90 gear oil...
Shock proof is fine for diffs, it's just gearboxes that don't like it. Not sure if it's good for clutchpack lsds but will be fine for stock vlsd or quaife. Also not good if you've fitted a diff cooler.
I'd define street use as any road registered vehicle being driven on public roads. How many Z32 diff failures have you seen, or heard of, directly related to the factory specified oil being used? For use in a Z32 TT Redline Oil recommends: "75W90 GL-5 Gear Oil Most popular Red Line gear oil, with thousands of applications for passenger cars, light trucks, and racing vehicles"
None, but in situations where the operating parameters exceed factory specs what possible harm can come from using a lubricant the meets and exceeds the capacities of the factory specified oil? It's really no different to engine oil, coolant, brake & clutch fluid etc... I'm sure the GL5 75w90 is a good oil. If the data from redline is to be believed (https://www.redlineoil.com/content/files/tech/ShockProof Gear Oil Tech Info.pdf) the shockproof will behave in much the same way but provide a thicker film and improved buffering between gear teeth, which in this case may go some way towards alleviating the problem. The only down side is the cost, but that shouldn't be more than $10-$20 per service.
shockproof can be used with clutchpack LSD's only they'll be noisy as no friction modifier. Fine for race use but would be way to noisy on the street.
I hadn't heard that Richmond recommend 85w140 so I'll give that a go , The shop that set my diff up were. Trans and diff specialist I do believe that they have set the diff up correctly they said the wear pattern was spot on . I'd say most of the noise is due To the es bushings .
Ah but did they set it up according to the instructions that came with the gear set? These gears need to be setup specific to the included instructions.
haha good, for anyone wanting to know dont try a 85w 140 its way to thick !! tried that for about 3 kms and ditched it. back to 75w 140 synthetic richmond oil
I though the same thing but given he only made it 3km it probably was still thicker, guessing crappy shifting cold.