Using Mobil-I in manual tranny

[Arup]

Hi Everyone,

I have a question, it is becoming very hard for me to procure Mobil-I ATF here in India for my ZF transmission, only ATF is recommended as standard fill in ZF manual transmission so I have been using M-1 ATF, recently, Mobil India has decided to take synthetic transmission fluid off the shelf and only sell it at a big premium through MB and BMW dealers.

As an alternative, I was thinking if it would be possible to use Mobil-1 Super Synth 15W-50 instead, it is easily available and should compare favorably to an ATF oil in terms of viscosity and I am sure would have better shear strength.

Thanks for any suggestions.

 

[Matt_S]

15w-50 is going to be much thicker than ATF. ATF is more comparable to a 5w-20. I wouldn't switch it to motor oil of any sort, though. Too many differences between that and transmission fluid. You'd be better off with a good quality ATF changed a little more frequently.

 

[Michael SR]

which ZF transmission is this? like in a 3-series BMW?

and you can't mail-order, right?

-michael

 

[Arup]

Hi Michael,

It is a TX-18 5 speed from ZF used in MB G Wagen of the 80s, that same vehicle is now being manufactured here in India.

Sadly synthetic transmission fluid is the domain of snob dealers and Mobil is feeding on that segment, there is no mail order here unfortunately, years back while living in NY in the 80s, M-1 products especially the transmission and diff fluids weren't available easily so I would order it from Mobil direct in VA.

 

[mechtech]

Like Matt S said, just use regular ATF and change it more often. I would do that in your situation, and never worry about it [plus you get extra flushing of particulate matter this way].

 

[Arup]

So the consensus is that no M-1 in transmission, regular ATF changed frequently is better.

 

[Matt_S]

quote:

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Originally posted by Arup:
So the consensus is that no M-1 in transmission, regular ATF changed frequently is better.

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Exactly.

 

[Arup]

Thank you all, truly appreciate it.

 

[MolaKule]

Sorry to disagree, but Mobil 1 5W20 or 30 would have a higher level of Anti-Wear additives than would any ATF fluid. If you can locate Mobil 1R, that would be even better.

If I couldn't find a synthetic ATF, and if that's what is speced for the transmission, I think I would go with a synthetic MO.

The only question would be is, does the Mobil 1 have the right friction modification for shifting. One would have to experiment to determine that, I.E., try it and see.

 

[tdi-rick]

Arup, what about Castrol Transmax Z ?
Do Castrol import it there ?
It is Castrol's full synthetic ATF that is used in MB and Porsche automatics, and has an excellent reputation here.

It has ZF TE ML-09, 14, extended drain certification.

A PDS in PDF can be found here

Rick.

[ October 27, 2004, 04:50 PM: Message edited by: tdi-rick ]

 

[Arup]

Molakule,

I was waiting for your response on this, couldn't have come at a better time. My understanding is same as yours on M-1, being a synthetic oil, it would have far superior shear strength and thermal stability than an ordinary mineral based ATF. Honda Accord used regular engine oil in their transmission and I have used M-1 with fantastic results there, I also use M-1 with my Honda RC 45 and till today, my gears are in fantastic shape even after high stress racing abuse. As for the friction modifiers, ZF trannies cant use any EP based oils as that would ruin their soft metal synchros.

tdi-rick,

Castrol is quite big in India as they are the oldest oil company here and have the biggest market penetration, sadly they like Mobil only sell the TransmaxZ in barrels to MB, BMW, Toyota etc. who refuse to sell it to the public.

 

[MolaKule]

quote:

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As for the friction modifiers, ZF trannies cant use any EP based oils as that would ruin their soft metal synchros.

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Friction Modifiers and EP additives aren't the same thing, but as you stated, the better film strength and higher shear strength should be better with the synthetic, and the viscosity shouldn't dip below 9 cSt, whereas the mineral ATF's have been known to shear down to around 4.5 cSt in manual trannies.

PCMO's, especially in the low to middle weights, have added friction modifiers.

Let us know how the M1 works out in terms of shifting, etc.

 

[Arup]

What is scary is that mineral based ATF comes out water thin from my transmission and I do a 10,000km change instead of the recommended 20,000km. I am sure M-1 would be much better in this regard. I don't think I can do any severe damage if I switch to M-1.

Will keep you updated.