While pulling a trailer and tractor this weekend, I noticed something I thought was strange. Trailer and tractor weight is about 9,000 lbs. I was going down the highway in OD at about 70. As I would start to climb a hill, I would watch the RPM's to determine when to downshift. On one hill I thought I would see if the truck would do it automatically. I had the gas pedal on the floor, and as the truck climbed the hill, it just slowed down to about 60. At some point shouldn't this truck automatically shift out of OD? If so, what do I need to look at since mine didn't? I'm no auto tranny pro, so I thought I'd ask you all, or is this normal? As the RPM's dropped the truck also seemed to get "quieter", then the engine noise would return as the truck regained it's speed and momentum. What you think?

 

when is the last time you have had your tranny serviced, fluids bands adjusted?

 

I have a built auto so I have to watch mine. It will hold OD longer than stock and my EGT's will soar while the cruise just keeps pouring on the fuel.

 

Service / band adjustment is happening in 2 days. It's due for a service, and as far as I know the bands have never been adjusted. We'll see.

 

Hmmm, my 02 had a torque converter lock up, so when it was towing and started up hill, the TQ would unlock, the RPM climb and it would still be in OD. If I pushed the loud pedal it might down shift to 3rd. Or I could push the OD lock out on the center if the shift lever.
Do you have an EGT did not see it in your sig. Would get one.

 

Ok, hate to sound dumb here, but need some clarification. Doesn't EGT stand for exhaust gas temp? Isn't that a separate gauge from Transmission temp? To accurately monitor the tranny, do I need both? I've thought about gauges, but all I've done so far is fuel pressure.

 

You should have EGT exhaust temperature gauge installed pre turbo. And a tranny temp gauge. EGT will show if you are working the engine too hard. 1250F is about max continuous you can run EGT. Mine would run 600-700 towing at a steady speed on the flat lands. Uphill it would climb toward 1400F it was time to back off.
Tranny temp would run 180 or so towing in summer time. Working hard it would go up to 220 or so. Backing up will really kick up the tranny temp.
Lot of excellent write up on the gauges and temperatures.
The above is my limited experience and opinion. Others may have other more advice.