Transmission overheating at idle

[Jeremy Parrett]

My transmission runs really cool with transynd.  Operating temp dropped from 185 to 150 during heavy loads here in Baja Sur.  
Problem is temps climb over 200, if I let the coach idle in gear for 2 minutes, say at a stop light.  
If I idle up out of gear, the temp drops right down to 150.
What could cause this?
I Had the hydraulic oil and filter changed before we left San Diego.

[Gerald Farris]

Jeremy,
The condition that you described is normal for your coach. Sitting still with the transmission in gear will cause fluid heating in the torque converter. If you are going to be idling for and extended time just shift the transmission into neutral to prevent overheating the transmission. Two, three, or even five minutes will do no harm, but extended periods of idling in gear while at a stop should be avoided.

Gerald

[Jeremy Parrett]

Thanks Gerald. I thought maybe the ATF fluid used might be the cause.