Gearbox notchy and rear diff noisy after Redline oil change

sifoo · Postby **sifoo** » Wed Nov 16, 2011 3:25 pm

Hi guys,

When I first bought the car, the gears were a little notchy going from 1st to 2nd (usually when the car was cold) and the rest of the gears were fine. I read that this was a fairly common problem especially with the NA/NBs. So I switch to the fully synthetic Redline MTL for the gearbox and Redline 75w90 for the rear diff.

First month of driving the gearbox felt great and the cold start notchiness was less obvious but I wouldnt say it was mind blowingly 'smooth like butter' as what everyone proclaims. Now three months later the gearbox feels VERY notchy in all gears. Noticeably first gear it literally 'clunks' in, the same sound when you put the car in reverse. Secondly, the rear diff makes a loud whine when accelerating and less when decelerating. I double checked the rear wheel bearings for wear by jacking each of the rear control arms up and turning the wheel but there was no problem there.

Any advice or thoughts as what is wrong?? The car has only 60,000 kms on it. All fluid were changed only 1,000kms ago.

Cheers
Paul

aviper4u · Postby **aviper4u** » Wed Nov 16, 2011 3:35 pm

hey paul the notchiness 1>2 is extremely common and every man and his dog has done the fully synthetic change as i did though all i experienced is a little easier when cold though thats it.

as for the whine of the diff are you sure the oil level is still correct other than that dont know.

also may help to put up exact mx5 model?

sifoo · Postby **sifoo** » Wed Nov 16, 2011 4:20 pm

aviper4u wrote:hey paul the notchiness 1>2 is extremely common and every man and his dog has done the fully synthetic change as i did though all i experienced is a little easier when cold though thats it.

as for the whine of the diff are you sure the oil level is still correct other than that dont know.

also may help to put up exact mx5 model?

Hey viper I used 1 bottle (1qt) for the rear diff and 2 bottles (2qt) for the gearbox. The car is NA8.

hks_kansei · Postby **hks_kansei** » Wed Nov 16, 2011 5:39 pm

did you fill them it until the oil started to leak out the fill hole, then simply wipe off the dribble and replace the fill plug?

if the oil wasn't level with the base of the fill plug, it's probably too low.

zossy1 · Postby **zossy1** » Wed Nov 16, 2011 6:07 pm

MTL is lighter than MT90 IIRC...?

With the warmer weather, my guess is MT90 would perform better than MTL.

project.r.racing · Postby **project.r.racing** » Wed Nov 16, 2011 6:18 pm

hks_kansei wrote:did you fill them it until the oil started to leak out the fill hole, then simply wipe off the dribble and replace the fill plug?

if the oil wasn't level with the base of the fill plug, it's probably too low.

this = win! :NETPOINTZ:

inbetweendaze · Postby **inbetweendaze** » Wed Nov 16, 2011 7:13 pm

Clutch cylinders

sifoo · Postby **sifoo** » Wed Nov 16, 2011 8:53 pm

hks_kansei wrote:did you fill them it until the oil started to leak out the fill hole, then simply wipe off the dribble and replace the fill plug?

if the oil wasn't level with the base of the fill plug, it's probably too low.

Yep filled right to the top of the fill hole.

NMX516 · Postby **NMX516** » Wed Nov 16, 2011 8:55 pm

Check your clutch fluid is at the correct level. If it's not, first place to look for a leak is the clutch slave - pull back the rubber boot and if there's fluid there, replace the slave. If not, still worth bleeding the system as old fluid can reduce the travel placed on the slave which then doesn't disengage the clutch quite far enough, making gear changes harder...

sifoo · Postby **sifoo** » Thu Nov 17, 2011 12:19 am

NMX516 wrote:Check your clutch fluid is at the correct level. If it's not, first place to look for a leak is the clutch slave - pull back the rubber boot and if there's fluid there, replace the slave. If not, still worth bleeding the system as old fluid can reduce the travel placed on the slave which then doesn't disengage the clutch quite far enough, making gear changes harder...

Thanks for the advice i'll check it out :beer: