Gear changes a bit crunchy.....

[deanb90]

Just bought 3 Quartz of MT90, was thinking MTL but it's coming into summer. The NC takes 2.1 which is a pain in the ass.

[Basho]

So why DID Harold recommend the 3 quarts of GB oil?

This is only my cynical take on it-

Harold sells oil and if I were selling oil I would think that if I sold 3 litres of oil it would be nicer than selling 2 litres of oil especialy if I told myself that I had protected my customer by selling them a bit extra from not being able to complete the oil change due to spillage or the dog drinking some and leaving them short .

Please do not ask how much is a 'bit' .

[Silvia]

If you've got 10 mins. here is an American white paper (2007)on test-comparing gear oils. Seems to have been commissioned by Amsoil and Amsoil came out well of course, but it's worth a look to see which failed and why etc.
http://www.synthetic-oil-tech.com/Gear% ... 0Paper.pdf

[deanb90]

swapped my GB oil in my NC to Redline MT-90. Gear changes have improved quite dramatically, more so than when i added the Nulon additive. The gearbox is fantastic now. Highly recommend.

[Silvia]

Thanks Dean, I've just about decided on MT90 too....

[RJ45]

Hi Silvia,

I started having crunchy/notchy gears after changing GB+Diff oils earlier this year.
After warming up it was fine, so being slack I went easy until it warmed up and bared with it.
6mths+approx 5,000K later it's come good on it's own, sorry can't say exactly when, possibly 3mths ago.
It was a gradual thing and its almost perfect now, say about 95%.

I suppose it depends how bad yours is & your level of patience first thing in the morning
Though I'm not sure why it improved, so not sure if patience is a valid strategy.
My guess is the oil has broken down a bit and is now just right, anyone else had this?

[93_Clubman]

...your level of patience first thing in the morning

Zero Good Strong Coffee=Zero Patience

[JG]

Have just had a quick skim through this thread, and noticed that there was some debate over whether GL-4/GL-5 was suitable for the 6-speed boxes...

I've just had a look in the NB8B service manual and it says this:

Specified oil:
Grade: API service GL-4 or GL-5
Viscosity: SAE 75W-90 (All season) or SAE 80W-90 (Above 10 degrees C {50 degrees F})
Capacity (approximate quantity): 1.70 - 1.80L {1.79 - 1.90 US qt, 1.49 - 1.58 Imp qt}

Now, onto the debate about the Redline Lightweight Shockproof, back when I had my R32 Skyline, I had notchy gearchanges... Originally I was running VMX-80 as I had had previous success with it in my AE86 in reducing notchiness/difficult changes (the bearings/synchros were pretty shagged in it), but it didn't seem to make a whole lot of difference in the Skyline. I switched to the Redline Lightweight Shockproof, and it did make a difference to low-temperature shifting. Being that I generally like to try new things/products that are out there, after a while I changed to the Motul Gear 300 (http://www.linkint.com.au/motul_gear_30 ... _page.html), which is also an SAE 75W-90 oil. From memory it didn't improve cold shifting much at all (if anything, made it a little harder... though this was nearly 6 years ago so my memory is a bit foggy), but shifting when hot felt (to me) to be much better than with the Redline.

I too have the pretty standard notchiness into 2nd when cold with the MX5 6-speed... It's something that I was aware was a common issue from doing some research/reading before I bought the car, so I'm not too concerned... I will be doing a gearbox and diff oil change in the next couple of weeks though, and am thinking of giving the SIN Gear oil from the Penrite range (http://www.penriteoil.com.au/pis_pdfs/0 ... 202011.pdf) a try as it seems to be fairly cheap and going by specs it 'should' be ok... if it goes ahead, i will report back on results

[Entice]

Just did mine in teh NA using MT90. there was quite a bit of crud in the old oil, so I FEEl as though I have done something good. Easy to do, shift feels smoother, but I havent done the top 90ml yet in the shifter....
GB is nice and quiet, still felt a tad notchy on 2nd, and I think the old oil was a bit low....

I'll do the top part when I can be bothered...

[NitroDann]

Thought Id pop in and note that in 7 pages we get 90% of people saying that not much made a lot of derence and 5% claiming unbelievable changes and the rest werent sure.

Dann

[Basho]

Thought Id pop in and note that in 7 pages we get 90% of people saying that not much made a lot of derence and 5% claiming unbelievable changes and the rest werent sure.Dann

There is also a positive note insomuch as that there aren't a mob of people reporting that they have had to pull the gearbox for repairs so I reckon the box must be fairly tough , notchy or not .

I just had a new clutch , and when it had been properly adjusted it made a fair difference as did the timing/ idle when adjusted , an unexpected bonus there.

I'm going to change to MT90 the next oil change and fully expect the gearbox will become a triptronic overnight.

[aviper4u]

Hi Silvia,

I started having crunchy/notchy gears after changing GB+Diff oils earlier this year.
After warming up it was fine, so being slack I went easy until it warmed up and bared with it.
6mths+approx 5,000K later it's come good on it's own, sorry can't say exactly when, possibly 3mths ago.
It was a gradual thing and its almost perfect now, say about 95%.

I suppose it depends how bad yours is & your level of patience first thing in the morning
Though I'm not sure why it improved, so not sure if patience is a valid strategy.
My guess is the oil has broken down a bit and is now just right, anyone else had this?

yea i understand what you mean by this though are you sure its not the fact of the warmer months and higher ambient temperatures in the morning?

[JG]

Have just had a quick skim through this thread, and noticed that there was some debate over whether GL-4/GL-5 was suitable for the 6-speed boxes...

I've just had a look in the NB8B service manual and it says this:

Specified oil:
Grade: API service GL-4 or GL-5
Viscosity: SAE 75W-90 (All season) or SAE 80W-90 (Above 10 degrees C {50 degrees F})
Capacity (approximate quantity): 1.70 - 1.80L {1.79 - 1.90 US qt, 1.49 - 1.58 Imp qt}

Now, onto the debate about the Redline Lightweight Shockproof, back when I had my R32 Skyline, I had notchy gearchanges... Originally I was running VMX-80 as I had had previous success with it in my AE86 in reducing notchiness/difficult changes (the bearings/synchros were pretty shagged in it), but it didn't seem to make a whole lot of difference in the Skyline. I switched to the Redline Lightweight Shockproof, and it did make a difference to low-temperature shifting. Being that I generally like to try new things/products that are out there, after a while I changed to the Motul Gear 300 (http://www.linkint.com.au/motul_gear_30 ... _page.html), which is also an SAE 75W-90 oil. From memory it didn't improve cold shifting much at all (if anything, made it a little harder... though this was nearly 6 years ago so my memory is a bit foggy), but shifting when hot felt (to me) to be much better than with the Redline.

I too have the pretty standard notchiness into 2nd when cold with the MX5 6-speed... It's something that I was aware was a common issue from doing some research/reading before I bought the car, so I'm not too concerned... I will be doing a gearbox and diff oil change in the next couple of weeks though, and am thinking of giving the SIN Gear oil from the Penrite range (http://www.penriteoil.com.au/pis_pdfs/0 ... 202011.pdf) a try as it seems to be fairly cheap and going by specs it 'should' be ok... if it goes ahead, i will report back on results

So I had the oils changed today...

Ended up going with Penrite SIN 75 (75w-90) for the gearbox, and the Motul Gear 300 for the diff (purely because I found that I still had a full 1 litre bottle of it sitting around here... just enough for the diff)

Initial impressions so far are that there is less gear noise from the gearbox, it is still notchy, though noticibly less so than before... I would say the notchiness was reduced by about 1/3. Other than that, it seems to feel 'smoother' and maintains speed/coast better (i.e. without requiring as much throttle) though i'm not sure if this is just an 'imagined' or 'perceived' result.

[Silvia]

Thanks JG
My discount Redline stockist has run out of MT90 until end Jan, so if it doesn't arrive for some reason , I'll use the Penrite alternative in the box...

[Basho]

Thanks JG
My discount Redline stockist has run out of MT90 until end Jan, so if it doesn't arrive for some reason , I'll use the Penrite alternative in the box...

You could grab some of Harold--- www.PerformanceLub.com