I've posted trans temp data before. This year I cracked another pinion in the 901 transmission. In building a new box, I decided to include everything that could make it run cooler. This included cryogenic treatment and REM polishing of all the gears and bearings, a different lube, and a different ring and pinion setup (following the factory setup isn't right!).

It worked. Big time! I have only been out for one event, but we lost over 40 degrees of temp! It ran so much cooler that we almost didn't have to run the pump or the fan.

Time will tell, but hopefully this transmission lasts longer than 2 years and doesn't kill everything in it.

Here is a chart comparing the old temps to what we saw this week.

Click to view attachment

Matt.
What lube?

Did you switch to the Lubrication Engineers 703 Monolec gear oil?
A local customer of mine uses that in his 901 box behind a 350hp carbed six.


edit: company name corrected

Whats "normal operating temp?" I'm scared to know what my temps run at now? I do notice that after about 6 laps at Sebring that 3rd gear is less cooperative then when I first went out.

The lube is Lubrication Engineers 9919. It's $30 a quart and comes in 5 gallon pails. Not cheap, but seems to work! I think a big part is in the REM and setup too. I think the factory manual is off a bit in how it says to set the ring and pinion up.

My old normal operating temp was 225-250 F. I think the new temps will be 180-190 F. The transmission certainly shifts better at 180F. Also, in talking to a retired bearing engineer, he says the bearing races start to lose their hardening at 250. I bet we ran north of 300 before we had the cooler.

Matt - what R&P setup method are you using?

We have the factory tool and then modified their setup instructions a little.