gearbox doom and gloom!!!

[QuickR33Melb]

I recently had my gearbox oil changed and to make sure I got some quality oil I went and purchased Syntrax 75-90w ($80 at trade price) with a teflon gear treatment ($15)

My problems started shortly after........

I noticed my 2nd gear started to crunch shifting either from 1st to 2nd or down from 3rd back into 2nd at 3000rpm+

Now ordinarily I would guess that the syncro is dead but the crunching only occurs after about 30 minutes of driving which indicates that the oil temp in the gearbox has something to do with my problem. To make things extra complicated the crunch into 2nd only occurs when I change over 3000rpm.

At the moment I take off in 1st....put the clutch in... wait for rpm to drop to 2000rpm and gently put it into gear... VERY annoying!

What do you think? Selector, synco????

Other than the crunch in 2nd the car is driving beautifully with no performance issues once the 2nd gear has been selected..

Jev

[Roy]

I dont know why but when i change gearbox fluid i find the box always tightens up for the first 500-1000kms. No idea why, but once i put some kms on the new box it comes good:confused:

[QuickR33Melb]

That is the advice that several of my mechanically minded friends have told me but its just a worry that it only happens in 2nd

[DezertEagle]

I got mine changed at Unique Autosports with the Diff Oil at the same time with Redline stuff.

Worked a treat and felt smooth as silk straight off.

[ylwgtr2]

people...whats wrong with the original oil?Nothing i say

[Roy]

Ill tell you whats wrong...It says Nissan on the container, and it doesnt look racey:)

I tried Castrol, Redline and Fuchs...the fact that they all feel as good as one another hopefully means my box is in ok nic...probably should stick with the one oil though????

If you are doing say 500kms track work per approx 6,000-8,000road kms...how often shoudl you be changing the gearbox fluid?

[B0oStEr]

Just guessing but I'd say the teflon treatment might have made the synchro cones a bit slippery.

If they don't have a bit of bite your box will crunch. Maybe it only crunches in 2nd because 2nd gear has dual synchros so they each get less pressure therefore less bite.

[lwells]

people...whats wrong with the original oil?Nothing i say

Nothing, but there is no harm in trying other products (well, unless they are inappropriate of course)

LW.