Gear change on 3.0 Sport

[z3cade]

I replaced the gearbox oil in my M roadster with castrol 75w 90 multi trans, the one you used. It made a massive difference with smoother gear changes from cold. I would say the oil is fine in your box so prob a problem somewhere else. Maybe have your clutch pipe bled again etc.

The multi trans oil is GL-4 grade. Its spot on for your box.

 

[lightning]

Yay! I will leave it in then

 

[vintage42]

....what kind of alien transmission is installed under my gear stick, that cannot survive on automotive transmission oil, used in just about every other car on the road!! lol

Many tightly-built manual transmissions use ATF (automatic transmission fluid), not gear oil. The Z3 Getrag was among them. It still works best on low viscosity fluids.
The Hillman Husky and Morris Minor I had back in the 60's would have preferred good old "transmission oil". Not so the Z3.

 

[t-tony]

Wasn't trying to start a debate just found the receipt the other day when unpacking . A rare thing for me as I normally lose receipts like that...

I didn't specify anything when I had it done, just asked them to change it. They could have put olive oil in it for all I know about automotive lubricants

I think, Gaz, inadvertently . . . . . . . ..... .

 

[vintage42]

... The multi trans oil is GL-4 grade. Its spot on for your box.

Its viscosity is 11.4, far thicker than the 7.7 of BMW's fluid. That cannot be best for shifting.
http://msdspds.castrol.com/bpglis/F...9A5C48025782000516BFB/$File/BPXE-8DHD82_0.pdf

 

[lightning]

The shifting is really good. Much better than with whatever was in before.

Except for the intermittent issue l started this thread with.
But as it's intermittent, it can't be the oil, surely?

 

[Brian H]

Just going to throw this in the pot, and hope it has not been covered before. I understand you still have your original clutch hose in place, have you thought about changing the clutch hose itself? It is a known fault that the side walls on old clutch hoses can "give" a little when warm, this would in turn change the bite point of the clutch as not all the fluid is being forced in to the clutch slave cylinder therefore giving an inconsistent clutch pedal depending on the temp of the engine. I replaced my clutch hose with a Stainless Steel one when deleting my CDV and the transition was a smooth one with no hassle. New hoses are approx £20 so in my eyes a no brainer to try.

Just a thought?

 

[z3cade]

Yes mines also had a braided hose fitted. As for the oil mines been perfect since the oil change so there's no problems using the castrol multi trans..

This has been covered so many times and a GL-4 grade oil is what you should use.

 

[lightning]

I'll try a new clutch hose. It looks easy to change.

 

[Brian H]

I'll try a new clutch hose. It looks easy to change.

I do not think you will regret it, please report back when you do change it.

 

[t-tony]

No wonder there's lot's of confusion re transmission/gearbox oil(types)
I took this from Carweb Technical Data which we have at work, for M44 BMW Z3 models. It states;
For Manual Transmissions with,
1, An Orange sticker- ATF Dexron 2.
2,A Yellow sticker- Gear Oil MTF LT1/2.
3,A Green sticker-Gear Oil MTF LT2
OR Gear Oil API GL-4 (SAE 80)
4,Black sticker- ATF Dexron 2 or 3.
5,No sticker- Gear Oil API GL-4 (SAE 80).

NOW, isn't that nice and clear so we all know what's what?
Incidentally, I changed the Auto box oil and filter on my car last year in accordance with Carweb Data, ie Green sticker on gearbox etc. on a car that is supposedly filled for life and it transformed the gear shifts etc. So it was correct on mine?
Hope this helps someone, Tony.

 

[lightning]

What if you had a sticker, but it fell off?

What oil would you put in then? I have no sticker, but l might have had one once....the car is twelve years old.

Thankfully the Castrol Syntrax oil is "universal" it doesn't care what sticker you have.

 

[hard top]

T-tony knows all about stickers.......

 

[t-tony]

My car is 14 years old but the sticker is still there, did you have a look? I'm only telling you all what Carweb says on their data. Don't shoot the messenger . Liam says his gear box is fine with that particular oil in it, it probably was before too. You have maybe got a random mechanical fault on your gear box which no oil may get rid of, ie synchromesh etc.and you might have to learn to live with it.

 

[lightning]

My post was kind of tongue in cheek!

 

[t-tony]

Hey no worries, I've got a fairly thick skin.
Night, hope the car behaves, Tony.

 

[vintage42]

No wonder there's lot's of confusion re transmission/gearbox oil(types)
I took this from Carweb Technical Data which we have at work, for M44 BMW Z3 models. It states;
For Manual Transmissions with,
1, An Orange sticker- ATF Dexron 2.
2,A Yellow sticker- Gear Oil MTF LT1/2.
3,A Green sticker-Gear Oil MTF LT2
OR Gear Oil API GL-4 (SAE 80)
4,Black sticker- ATF Dexron 2 or 3.
5,No sticker- Gear Oil API GL-4 (SAE 80).
NOW, isn't that nice and clear so we all know what's what?...

I think all the M44s are orange. Anyway, the Dexron 3, and MTF LT1 and LT2, are all more modern ATFs of similar low viscosity around 7.7.
The 80W gear oil is thicker and I don't think there will be a Z3 transmission for it.

 

[lightning]

Is there really that much difference between the recommended 75w oil, and 80w oil?

I have some SAE 140w "classic" gear oil, now that is thick. But SAE 80w rather than 75? Would there be a noticeable difference?

 

[vintage42]

Is there really that much difference between the recommended 75w oil, and 80w oil?... Would there be a noticeable difference?

The recommended material is called a fluid, rather than an oil. The recommended viscosity of the fluid is 7.7. Viscosity is not the same as weight. The Castrol 75W-90 gear oil has a viscosity of 11.4. As to whether the difference between 7.7 and 11.4 is noticeable, try the gear oil and let us know what you think. Cold shifts, and winter shifts, should be harder, while hot shifts should be OK.

 

[vintage42]

... I have no sticker... Thankfully the Castrol Syntrax oil is "universal" it doesn't care what sticker you have.

And conversely, a transmission with no sticker doesn't care what you put in it?