Originally posted by todras:
Drom Terry today

...today I opened up a V6 MTX from a customer in
Linden ,Mi,Todd M...99 Contour V6 ,over 100,000 on
it,supect diff(kicking back thru steering wheel,couple
of teeth starting to go on the diff gears),bad 3rd
gear syncro....

This trans was running red ATF....,about 1/3 of the muck on the magnet Vs Petes and the case was very clean,no black stain



This is significant information.

Personally, I will not be using Red Line MTL until there is a better answer to what is going on with their fluid. I would say that it would be a way to err on the side of caution.

I'm sure that a lot of this would have never happened if there was not so much confusion about just what Ford "honey" really is. If Ford would have been more forthcoming about the composition of their fluid or at least about it's specs people would not have been casting about trying to find a reasonable alternative. Along with this is using a fluid that is priced at about $20.00 a quart for an entry level or near entry level car is unconscionable.

Just like engines, manual transmissions will work just fine with a range of viscosity. The fact that the MTX75 was marketed in the US for over 5 years using ATF pretty much means that it was suitable. Longer if you count the Mondeo. It was even considered "lifetime" fill. Then for Ford to replace it with a dedicated fluid with little information as to what it is just muddied the water.

Ford's own spec sheet for "honey" says it is suitable for manual transmissions requiring GL3/4 75W90 gear oil. Now during the course of this thread we learn that it may really be relabeled Castrol SMX-S which Castrol says can be used wherever a 75W85 GL3/4 gear oil is required. That's hardly anything that will pin down just what it is. Also Castrol does not market this product in the US.

Considering that the MTX75 started life using Mercon ATF and then later got moved to something that appears to be a manual trans gear oil in the 75W90 or 75W85 range pretty much indicates an improved manual trans oil that is either as thin as ATF or as thick as 75W90 should work fine.

So what happened to the Red Line?

We don't have a good answer. We don't have a used oil analysis from the trans that failed. We don't even have a used oil analysis of the trans that Terry opened that was rebuild 14,000 miles ago and had only used Red Line MTL.

Yes, we have two virgin oil analysis that show that Ford "honey" and Red Line MTL are not an exact match. But then, a virgin oil analysis of ATF would also not be a match and it worked OK for over 5 years before Ford changed the spec.

I have it from good authority that there is no reason that the best manual transmission fluids cannot be GL rated. What is more important is what was used to gain the GL rating. Some GL additives can be damaging to yellow metals, but not all. If the right additives are used to incresase GL ability, there is no reason that it cannot meet GL5 spec. Just as important is what friction modifiers were used so that on balance the transmission will live and shift properly.

It looks to me that the Red Line MTL in a MTX75 may be bad news. It looks like the anti oxidant additives were depleted and allowed the oil to start breaking down on the trans that Terry opened for inspection. Until I know more, I will not use it.

Does that mean the Ford "honey" is the only answer? I doubt it.

(FLAME SUIT ON)

Jim Johnson 98 SVT 03 Escape Limited