Hi,

It is nearly impossible to find synthetic ATF here in India, so I am considering using Mobil-I super synth 15W-50 instead. From what I understand, M-1 has much superior shear strength as well as thermal stability than regular mineral based ATF, there leading me to believe that it would be much superior alternative to regular ATF and closer to synthetic transmission fluid. Sadly, my ZF tranny specifies ATF only as lube or else I could use gear lube, regular mineral based ATF shears so easily during summers and it comes out with water thin viscosity during drains, I am really worried about the level of protection offered by regular ATF.

What would be the cons if any of using M-1 in my tranny?

Not sure the ramifications of running motor oil in your manual tranny. If it specs ATF you hve to be careful to not go too thick with certain trannies. The dealership service rep allowed I could run 10w40 motor oil in my F150 maunal tranny (Mazda M5OD), but I went to Mobil One AFT.

They sell Mobil One motor oil, but not Mobil One ATF in India? But Redline ATF would be even better IMO. It has more antiwear and should be as or more sheer stable than Mobil 1.

I now have the Redline D4 synthetic ATF in my F150 manual tranny. I believe they have an Australia website for Redline and maybe you could have it shipped from them.

Thanks for the reply Tall Paul,

Afraid that importing Redline MTL from Australia would be a super expensive proposition. Looks like I have to stick to thin mineral based ATF till Mobil or Caltex takes pity on us poor souls. Synthetic M-1 as well Catex is available here in India and Indian companies also manufacture synthetic tranny fluid, problem is that they are only for OEM fills, not for the general consumer.

Maybe the motor oil would work. You could check with the tranny manufacturer, but I think Mobil One is light on additives (but then so is typical ATF). So maybe your best answer for now is to do frequent fluid changes. If you have the dealership do the change will they put in synthetic?

At one time, Ford's Focus used ATF, motor oil and gear oil in the MTX-75 5-spd transmission depending upon where the car would be exported to. US production used ATF initially but a change to gear oil was made sometime during 2001 because ATF did not do the job. I experienced stiff shifting when the fluid was cold.

After switching from ATF to gear oil, I got much better results. Of course Mobil 1 will be fine but I used SynLube and think it is the best. I also drained the ATF out of my current manual transmission (Ford Ranger) in favor of SynLube gear oil as well. No problems.

The problem is that ZF cant use regular EP based sulfur additive gear oil either in GL4/5 form. Reason is that soft metal synchs used in the tranny would self destruct if etching gear oil is used, synthetic gear oil/ATF or mineral based ATF OTOH don't have high amount of sulfur and are therefore much safer to be used in ZF tranny, M-1 has higher shear strength than any ATF except maybe for the synthetic ATF and carries no etching sulfur additives, therefore logically they look to be the safer and superior bet.

Girkha,
I work for a very large transit agency in the states. After much testing and discussions with ZF we were allowed to use multi weight oil in our ZF HP 590V & 500 Allison V731 trannys. To our amazment were were getting 60k miles between oil changes and it actually ran cooler wich is a problem with this type of ZF.
Currently we use 15w40 Penzoil Long Life it shears down in a few hrs and has saved us hundreds of thousands of dollars a year just in the difference between 15w40 and synthetic not. We have not experienced cold weather start up wear and heat is not a factor any longer
Were expanding our test to include all the ZFs in our fleet. It will be so nice to have only 2 fluids here to use for engine and trans.

Eugene,

Many thanks for your reply, so this means I can give M-1 a try in my ZF tranny, would be much better alternative than the water thin mineral based ATF I have currently in my tranny.I am really worried when I am off roading in 52c weather.