Use ATF that's Mercon V rated in manual???

[Dr. T]

My 6 speed manual transmission specs out using ATF Mercon/Dextron IIe. Would using one that's Mercon V rated work better to provide smoother shifts (especially the 2nd gear synchro crunch when cold)???

 

[Whimsey]

I believe that the Mercon and Mercon V ATF are totally different and use of it would cause problems with your manual transmission. I have a 2002 F-150 with the 5 speed manual transmission which calls for Mercon ATF. It's shifting quality is "rough" to be kind! I asked Ford's service rep's about using a synthetic ATF to help the shifting quality. Even using Ford's own synthetic Mercon ATF. They said no! Even their own synthetic Mercon ATF is not suitable for my manual transmission! It's Ok for an automatic transmission that requires Mercon, but not for the manual transmissions that require Mercon! Ironically I have a '96 Ford Contour with the manual transmission that also requires Mercon and yet Ford recommended I change to a new synthetic ATF, their own "special" offering. I changed to their "gold" fluid and noticed no differecnce in shifting quality. Cold shifting seems to be a bit easier, but that about it. I thought I read of another individual who changed to a synthetic ATF for his manual and it didn't change the shifting quality. Actually overall the shifting quality is not terrible with the Mercon ATF. You just have to shift "carefully", not too high into the rpm's. Probably the best thing is to make sure you change the ATF fluid every 30,000 miles at the minimum.

Whimsey

 

[widman]

From what they told me in my day at the shop I would not do it. There are issues with seal compatability if it has already had the Dexron/mercon product.
Would probably be fine if you were replaceing seals at the same time.
But it shouldn't be necesary.

 

[unDummy]

Use MTL or MTF. I never liked ATF in manual transmissions.

There is no problem with using the Mercon5 in place of Mercon. Its just a synth!

 

[TooSlick]

Dr T,

A sythetic ATF like Mobil 1 should work fine ...this is basically equal to a 0w-20 engine oil in terms of cold flow properties.

I have several customers running synthetic ATF in BMW and Volvo transmissions - no complaints.

Ted

 

[Dr. T]

Yeah, I'm running M-1 ATF synth. right now...just wondering why it wasn't Mercon V rated and if a fluid that was would make an improvement.

 

[TooSlick]

Dr T,

Mobil hasn't bothered testing their synthetic ATF to qualify for Mercon V, although it might well meet this spec with just a minor reformulation.

The other product that works well in these ATF manual transmission applications is Redline MTL. However it won't flow as well as a 0w-20 synthetic ATF.

TS

 

[dickwells]

Tooslick. Got anyone using M-1 in the GM L460E with success? In the new silverado in particular.

 

[jason07-1zzfe]

I really did not like the M1 ATF in the 4L60-E on the 2000 Jimmy. Shifts softer and sloppier/less precise. That was with a 50% change out on the original OE fill. (dropped pan/filter and refill).

I will be using Red Line D4 ATF next. Changing it as soon as weather warms up. (I hate winter!)

 

[unDummy]

Which 6 speed crunches when cold?

Next time go 100% with Mobil1 ATF. Mixing fluids isn't good when making negative comparisons and drawing a conclusion.

Redline MTL is 5w30. It is very close to 0w20. How long is a manual transmission cold anyway?

Neo MTF is even thinner than the 0w20 synth ATF and 5w30. Again, other than Santa Claus's new 6 speed deerless sleigh, I don't see why anyone would need anything thinner than MTL.

Screw the MPG improvement that OEM's got by using super thin gearoils(ATF in manuals).

 

[ssmokn]

I ran Mobil 1 in my 4L60E (Impala SS) for quite some time with no problems. This trans even lived behind a 396 stroker for a while until I pulled it out and replaced it with a "built" performance transmission. When I pulled it out is was running fine.

The new transmission is using Amsoil ATF because the builder uses and likes the stuff. Personally, I would have stuck with Mobil 1 (just easier for me to get) but I didn't want to hear about how I should have stuck with Amsoil if I had a problem later. I also bought a couple of cases of Amsoil ATF for my future transmission fluid changes.

 

[jason07-1zzfe]

quote:

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Originally posted by unDummy:
Next time go 100% with Mobil1 ATF. Mixing fluids isn't good when making negative comparisons and drawing a conclusion.

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Well shouldn't replacing half of the fluid with NEW fluid make it perform better....not worse? And what if it improves when I do a drain/refill with Red Line? Will it then have been caused by some other unknown force because half of the fluid can't possibly have any effect?

 

[unDummy]

I call it the psychological effect. Other forces are right foot location, weather conditions, fluid level, owner expectations, transmission condition............If the transmission is shifting sloppy or less precise, then I would think that there was a mechanical or electronic problem to deal with.

Another thing to consider is ATF mileage usage. If old fluid was saturated and there was varnish/crud/sludge anywhere in the ATF passages, then the new fluid will act like bleach. It will quickly become dirty again. It is important to change ATF regularly. For cars with ATF change intervals over 30k miles, then you should change it again(after about 1-3k miles) to remove anything that the new ATF scrubbed! This is important with partial fluid changes(drain/refills of pan) and less so with thorough pro-flushes.

Fluids sometimes use different additives. I don't care for mixing. Pick one and stick with it. Playing multiple fluids is asking for trouble. It is well known that some have different additives/TAN/TBN/viscosities/viscositycurves...... Mixing two aint all that good.

Some people confuse shift quality with the fluid when it is the actually valve body/ECU/TCU/whatever that is controlling the transmission. Some automakers program the transmissions to slip for smooth seamless shifting. Fluid changes with these transmission require the ECU to be reset so that the vehicle relearns and adapts to how the transmission/user are working. Pretty scary. This is why each automaker is now specifying their OWN type of fluid. They want seamless shifting(i.e. controlled slipping) and the least possible change in variables. I prefer shift kits/VB mods that allow "click" shifting.