Z1 Gearbox Oil

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SCORPION
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Z1 Gearbox Oil

Post by SCORPION »

Way back in 2009 Roger Briggs sourced some Mobil SHC 630 and distributed it to a lucky few.
Last year I got round to putting it in my car. Since doing so the gear changes are definitely more "crunchie" when cold. I'm a great fan of synthetic oils, especially Mobil as I worked for them for 33 years, but the non synthetic (I think it was a Castrol 75w90) the garage supplied in 2006 was much smoother with hardy any friction on the gear change.
What is your experience with SHC 630?
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Racing Tortoise
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Re: Z1 Gearbox Oil

Post by Racing Tortoise »

None. I'm virtually certain (w/out checking the invoice) that whatever ML put into my Z1 at the last service was Castrol of some sort or other, as that's the name that rings a bell from the relevant invoice.
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Green Genie
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Re: Z1 Gearbox Oil

Post by Green Genie »

Yup he's right... mine was serviced at the same place ML the oil they used was Castrol SMX synthetic gear oil.

No crunchy gear changes for me :D
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Del
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Re: Z1 Gearbox Oil

Post by Del »

Green Genie wrote:the oil they used was Castrol SMX synthetic gear oil.
I’ve used the same stuff in my Z3 Getrag box. It’s one of the few remaining, fully synthetic multi-grade (75W-90) gear oils, still readily available in retail outlets and that is still a true GL4 rated gear oil. GL4 being a slightly more cautious stance for older “classic car” gearboxes the synchromesh in which might be affected by the larger amount of anti-wear chemicals in modern GL5 gear oils.

http://www.opieoils.co.uk/p-739-castrol ... 5w-85.aspx

Only an observation (I’m a Z3 owner) and largely ignorant about Z1 mechanicals, but having just looked up that Mobil oil you mention purely out of interest (mono-grade SAE 90) and it struck me as being quite a thick oil:-

http://www.grainger.com/Grainger/MOBIL- ... -Oil-6Y778

:)
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Racing Tortoise
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Re: Z1 Gearbox Oil

Post by Racing Tortoise »

I might be dreaming it but I think I recall a suggestion that using thicker gearbox oil helps minimise an inherent rattle that you can get from Z1 gearboxes when warm. Something to do with the torque tube set-up if I recall correctly what one of our Dutch or German pals mentioned on the 2009 Silverstone visit. My green Z1 used to suffer from this although I haven't noticed it on the black one (which is much lower mileage).
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Bluebaur
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Re: Z1 Gearbox Oil

Post by Bluebaur »

To add a little more information on the use of Mobil SHC 630 in the Z1 gearbox. When I purchased my car in 2008 it had already been in this country for 10 years. The previous UK owner had invoices available to show that the car had undergone engine and gearbox oil changes. Whilst the garage had specified the engine oil grade, the invoice omitted to show what grade of oil had been used in the gearbox.
From the first journey I made in the Z1, at warm tickover there was a discernable noise coming from the gearbox until the clutch was dipped. This reminded me of a previous car ie, a BMW 325i Sport that I had owned for over 4 years. One of the best BMW's ever made in my humble opinion BUT the gearbox rattled on warm idle. The local dealer said "it is the layshaft in the Gertrag gearbox chattering, they all do that". A slightly thicker oil will quieten things down a bit, but at the expense of slick gearchanges when cold.
I agree with Chris that Mobil SHC 630, a synthetic SAE 90 oil designed for gears and bearings mainly in heavy duty applications ( Mobil spec sheets words) and the BMW specified oil, does make cold changes more clunky, but on my car it has nearly eliminated gearbox chatter.
As an aside, Mobil SHC 630 is an oil that is not readily available in the UK other than in 20 litre or larger drums, but is freely on sale in the US in 1 litre quanties.
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Re: Z1 Gearbox Oil

Post by Racing Tortoise »

Good to see my memory hasn't failed me totally!
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Re: Z1 Gearbox Oil

Post by felix »

Del
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Re: Z1 Gearbox Oil

Post by Del »

That’s an interesting range of oil usage. The Redline MTL looks quite thin and presumably gives good cold shift performance whilst the Mobil SHC looks to be at the other end of the scale. I guess (like with the older Z3s) the BMW recommendation in 2013 is simply to refer to their recommendation made in say 1990 – but gear oils have evolved in the meantime.

The Castrol UK oil finder site (for the Z1) mentions adherence to the same range of gearbox oil labels as the Z3 which can include Orange indicating the use of ATF and two possible Yellow MTF labels. I know that ATF is often used as a cold shift problem solver whilst at the same time being known for causing “gearbox rattle” at higher operating temperatures in some cases.
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Jet
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Re: Z1 Gearbox Oil

Post by Jet »

As a recipient of Rogers group buy, I did notice the difference, but perhaps for different reasons. Renewing the oil got rid of a buildup of 20year sludge and metal dust. Now gear changes are sticky from cold, but smooth when warm, which I prefer as I never drive before warming the engine.
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Re: Z1 Gearbox Oil

Post by felix »

In 1998 my 325is would have great difficulty going into 2nd gear in the winter time - it was as though there was a bar across the 2nd gear gate. The requisite amount of MTL later and the car dropped into 2nd when cold as though the box was warm. Night and day difference.
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Re: Z1 Gearbox Oil

Post by TJS »

I also changed the gearbox ol via Rogers earlier group buy, more peace of mind as there was no record of it being changed in the service history. As with others the gear change isn't great when cold, but then so are most cars. I do still get an occasional whirring noise from the gearbox when stationary which disappears when the clutch is disengaged, I suspected a worn clutch release bearing.

I am about to change the oil in the TVR gearbox, Borg-Warner T5, which, as with the Z1, isn't great when cold. The specified oil is Mobil ATF 220 ..... Auto transmission and PAS fluid. Current thinking is to use Castrol SMX or Redline MTL GL 4, the latter being strongly recommended for road and race / sprint use.

Conclusion? Redline MTL is going into the TVR and, if a noticeable improvement, the Z1 also

TJS
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Re: Z1 Gearbox Oil

Post by Del »

TJS wrote:Conclusion? Redline MTL is going into the TVR and, if a noticeable improvement, the Z1 also
The lower Redline viscosity number of 70W (viscosity of 70 at winter temperature) should give good cold performance.

BMW MTF-LT-2 was very similar but the Redline SAE rating looks to offer an improvement on the cold performance.

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Re: Z1 Gearbox Oil

Post by TJS »

2.5 litres of Redline MTL went into the TVR yesterday afternoon.

A significant improvement in gear change quality and reduced noise from cold and when hot, bear in mind the definition of "hot" in TVR terms is thermo nuclear. The service schedule is 12k miles or 2 years for diff and gearbox oil changes, I will be lucky to cover 2k miles in 2 years.

I would have no problem using it in the Z1 with its extended comparitive gearbox service requirement as per Felix earlier recommendation.

TJS
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Re: Z1 Gearbox Oil

Post by ChrisS »

Does anyone have any further comments following experience in the past four years? I had my Z1's external gear linkage replaced a couple of years ago. That has improved shift quality but it also highlights resistance in the gearbox when the engine is cold, especially in winter.

My regular service garage thought the gearbox needed a rebuild but couldn't store the car easily while the box was away being repaired. When I took the car to a gearbox specialist, he reported that it probably just needs an oil change. That's good news, especially for my wallet.

Is there anything better than the Mobil SHC 630 mentioned in the handbook?

All advice gratefully received!
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Re: Z1 Gearbox Oil

Post by Pat Slade »

Hi all,

I put Redline MTL in my car early last year when I serviced it before the Pyrenees tour. Been really pleased with the result.
Far slicker engagement when the box is cold. With the "original" spec oil the baulking was often bad. At cold start often used to have to get 2nd before any chance of getting 1st. When hot it rattles slightly more than it did with the Mobil "original" oil.
I don't think that any of us abuse our cars enough, or do enough miles,to make much difference in an engineering sense. Many of the E30 boys swear by it!

Pat
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Re: Z1 Gearbox Oil

Post by Jet »

ChrisS wrote:
Is there anything better than the Mobil SHC 630 mentioned in the handbook?

ChrisS
Yes, dont drive with a cold engine and gearbox, always let it sit idling for a few minutes and gently massage the gears as the temperature rises, its usually 1st gear the most problematic, but thats normal, try going to 3,2,1,4,5 as opposed to 1,2,3.... for some reason mine slips into 3rd but not 1st to begin with, but once its warmed up, the gremlins go to sleep.

Definitely Oil change is the first thing to do.
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Re: Z1 Gearbox Oil

Post by felix »

Slow shifting and double clutching helps as well.
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Re: Z1 Gearbox Oil

Post by ChrisS »

Redline MTL has been in for a couple of weeks and I've had the opportunity to try out the shift quality at ambient temperatures from 0 to 10 degrees C. It's certainly much easier to engage reverse and first from cold and the shift quality has generally improved even when the gearbox is warm. All together a good way to spend £40 on the Z1!
Thanks for all the advice.
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Re: Z1 Gearbox Oil

Post by ChrisS »

"Slow shifting and double clutching helps as well." I always shift slowly and synchronise the engine speed on downshifts, though I don't consciously double declutch on upshifts. Just mechanical sympathy really.
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Re: Z1 Gearbox Oil

Post by felix »

ChrisS wrote:"Slow shifting and double clutching helps as well." I always shift slowly and synchronise the engine speed on downshifts, though I don't consciously double declutch on upshifts. Just mechanical sympathy really.
I meant slow shifting and double clutching when the box is cold - not really required when the box is warm/hot. Then a much smaller degree of mechanical sympathy is needed.
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Re: Z1 Gearbox Oil

Post by TJS »

Time to wake up the zettie and replace the engine, gearbox and diff oils.

It's fifteen years since Roger purchased and kindly distributed the Z1 specific Mobil SHC 630 ..(time flies!)

Given it is still only available in 208 and 20 litre drums what is the current small volume gearbox oil of choice ?

Castrol SMX has been rebranded as Castol Transmax Manual Multivehicle (synthetic 75W-90 GL4)

Opie Oils recommend Mobil Automatic Transmission Fluid

https://www.opieoils.co.uk/f/706233/433 ... x-oil.aspx

or is the recently changed Redline MTL 75W-80 GL4 (previously 70W - 80) the way to go ?

Additionally, is the gearbox oil drain plug magnetised ?
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Re: Z1 Gearbox Oil

Post by F.Brossaud »

I have been trying to buy SHC630 last year (in 20l drum) but I was not able to find any ... I am wondering if Mobil is still producting it.

I investigated and we decided to go for Minerva synthetic 85W140 which was the closest to the original SHC630 viscosity and I found the "original feeling". This oil is french brand designed for trucks, heavy duty for extreme pressure (basically same as SHC630)

NO ATF oil, no way !!!
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Re: Z1 Gearbox Oil

Post by TJS »

HI Fred

SHC630 is available in the UK @ £350 for 20 litres. https://www.opieoils.co.uk/basket.aspx

The oil spec no longer shows up on BMW's service info but it seems Redline MTL is the way to go
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