I swapped out the 5600 to MTL about a month ago. I like the improvement in the shifting once it warms up. Notchy third is sill notchy but better.

One thing I noticed right off the bat is an increase in tranny temps.

Before empty running would be around 130-140. Now its' 160-170.

Before running with a 32ft gooseneck cargo trailer loaded to the hilt would be 180-200.

Sunday running a 24 beavertail gooseneck unloaded it was right on the edge of 220. And that was in the rain.

If it was getting that warm unloaded, what's it gonna be like loaded with a skidsteer and implemets.

One other curious item from sunday. When it was at the edge of 220 and I had to downshift to reduce speed coming into a town, the temp would DROP to 170. Not gradual, but drop. Once back into 6th and going down the road it would creep up again. Almost like the coolant temp gauge when the thermostat opens.

Any ideas? Thanks in advance.

 

Yes, this is common. During much testing three years ago we found nothing ran cooler in the tranny than the factory lube. Torco RTF was right there with the factory fill as well. The rest would run hotter and some would rocket the temps up.

Don~

 

Thanks Don!

How were the shifting characteristics with the Torco RTF? Comparable to MTL?

I checked the RTF out on their website. I "assume" that the RTF and 5600 are well compatable? The reason I asked that is that I never heard anyone mention it for 5600 fill.

If I had known that the temps were gonna jack up like that I would of never gone with the MTL.

It's a shame that the good shifting characteristics have come with such a compromise.

Thanks again!

 

I wouldn't worry much about higher trans temps with the MTL. The lube itself is VERY stable even at scary high temps, so unless you're seeing over 260, the lube isn't going to be a problem.

However, lube isn't the only thing affected by high temps. Gears, seals, etc all are affected by them.

That's weird that the MTL gets so warm. Especially in light of the fact that the viscosity specs are similar to the spec lube

Don, any testing with the Royal Purple SynchroMax???

Oh-- and get working on my sticks


Justin

 

The MTL has friction modifiers to improve the shifts, this makes it less "slippery" than the recommended oil and is the cause of your higher temps.

Like Justin said, the oil can handle the heat. I'd limit it to 250 degrees out of concern for seals. A downshift to direct drive (5th) will cool it off rapidly if it starts heating up too much.

 

Thanks Guys!!