Cheap ATF fluid, worth the risk?

[Martyn_n]

Did you use a new gearbox pan gasket when you changed the filter? There are several problems associated with removing the gear fluid oil pan when changing the internal fluid filter. The first are seized steel bolts in the gearbox alloy casting due to galvanic corrosion---but since you didn't mention any problems I guess that went OK. The other is distortion of the fluid pan mounting flange due to over-tightening the securing bolts. This is a the start of viscious cycle where the bolts need be tightened even further to achieve a seal making the problem worse next time or impossible to achieve a good seal. Only easy solution is a new pan.

MY guess then is you have some sort of pan gasket leak which may be cured by reseating it or tweaking up the bolts slightly but if the pan flange is badly distorted that may not be possible.

ps I take it you tightened up the 2 drain plugs [ pan and torque convertor ] with new washers? Other possibility is you have a leak in one of the pipes/banjo unions that lead /return from the front transmission fluid heat exchanger in the radiator.

I think you have hit the nail on the head with the washers. In my rush to get the job done at the weekend I made the rookie mistake of re-using the washers, i've been chasing replacements this morning. Hope the one that is leaking is the convertor as I have had to leave the car without a drip tray for the next two days and at least there is a chance that the drain is near the top limiting the losses! Don't think I over tightened the sump (was shocked at the torque setting, but stuck to it anyway) so I have not distorted it and it did not leak before. Needless to say I am seriously annoyed with myself.

 

[clever dicky]

Did mine end of last summer no probs. The sticky by Ollie ? i think was very helpfull. Also did the new seals for pin bush housing same time. Got the absolute best proper new oil from a guy on ebay who told me hes a member on here at fantastic price. Think he said his name was MoMo ? cant be sure though.

 

[steptoe]

No one did, the point is that a spec is a minimum, an oil can exceed a spec. I don't know if mb oil exceeds these specs and have never claimed otherwise.

If it exceeds the spec then it'll be a different spec

 

[Aoraki]

No one did, the point is that a spec is a minimum, an oil can exceed a spec. I don't know if mb oil exceeds these specs and have never claimed otherwise.

Wind your neck in, I never said you had!

 

[NOMONEYBUTAMERC]

Never had a problem with Comma ATF . All motor oils meet given specs, and as others have remarked , a spec is a spec. To the best of my knowledge MB do not manufacture / process any oil . They do charge a lot for their symbol on the container though !

 

[Bellow]

All motor oils meet given specs, and as others have remarked , a spec is a spec.

In the lab it passes. Half way through it's life in the engine, gearbox, diff, etc - how's it doing? Still the same? Would it pass the spec tests then? Is your car something on which it's very survival is dependent upon the continuing protection of its oils? Or is it a one shot lab test?