Recent Diff Overhaul

[Marko R1]

hi guys,

i had my diff rebuilt with new bearings, seals & new nismo shims for my r32gtr (2 way diff).

prior to having it rebuilt, it used to make a humming noise between 60-90km...since the rebuild it makes the same noise but not as bad.

what could this be? maybe the fresh oil helped with some of the noise?

or is it normal for a 2way diff to make this sound?

if i have the radio on medium level i cannot hear the diff, im just really fastidious when it comes to my gtr

thanks

marko

[Marko R1]

i was also thinking of trying redline diff oil, it did wonders to my gearbox on my old gtr

[wlspn]

Generally speaking, period noise (noise only heard at a certain speed, etc) is caused by crown wheel & pinion wear.

It can be quite easily missed when building the diff as it is not always noticeable (unlike pitting, etc)

It can be very slight wear, not much different to normal running marks, but enough to cause noise.

A thicker oil after building could have slightly improved the noise but won't fix it, as you've found.

If this noise was one of the things you mentioned you wanted fixed when talking to the place that built the diff maybe talk to them & see if they would consider looking into it as warranty...

[Marko R1]

i had terry @ award diff build it for me - nice guy & knows his shit!

i'll speak to him tomorrow, he initially thought it could be a half shaft that might have twisted when i ran it @ the drags but i i think its gears itself, i.e. worn gear set

i wonder if adjusting the backlash can eliminate the noise, maybe if it was running a bit looser it will let more oil in between the gears?

[turboedsloth]

if you run it at the drags increasing the backlash could cause more damage. as wlspn said, i would be looking at wear on the crown wheel and pinion as this is what usually causes that noise at that speed. ask terry if he took a reading of the tooth contact, being as good as what you say he is he should have seen the reading and noticed it was out

[Marko R1]

will do

[Rolls]

Once a diff starts whining that is it, it will never be quiet again. It is almost always caused by wear on the crown and pinion teeth, a common cause is people putting a diff back together and not correctly setting the backlash, this causes accelerated wear which can turn a silent diff into a noisy one in just a few kilometres

Changing the oil can decrease the noise ever so slightly, but it will never work miracles, this is most likely what has happened with you.

Edited July 6, 2010 by Rolls

[Marko R1]

this is the thing though - the diff made noise before i had it rebuilt.

this is why i had it rebuilt, due to the noise & whilst it was apart i decided on a full overhaul as the diff tags were snapped off

[Marko R1]

i should add that the noise also started after a night at the drags as well, i than had it rebuilt

[Rolls]

Yeah but when you get a diff rebuilt they don't replace the crown and pinion gears unless they are f**ked, so being as these are still 100km+ old still that's why it is noisy.

[R.3.2.G.T.R]

i had my diff rebuilt with new bearings, seals & new nismo shims for my r32gtr (2 way diff).

hi marko

im looking to do the same, how much did it set you back and the nismo shims, was it supplied by award?

thnx

[Marko R1]

yeah it was all supplied.

bearings, nismo clutch pack & seals for $700.

i took out the diff myself - labour for that might be an extra $150?