V730 temperature question

[Cary and Don]

We decided to be good to our V730.  The pan had a huge dent in the bottom so we pulled the pan and beat the dent out.  That made a lot more room for the oil pick up.  Gave it a nice refill of new Delo 400 15/40. 

Now for the odd part.  The gauge on the transmission temperature had been reading about 10 degrees hotter than the engine temp sitting and idling. Now the Trans temp gauge reads about 210 sitting there in neutral.  The IR gun reads 147 at the temperature sensor even though the gauge says 210. The two used to agree on the temp.  The engine temp was 170 at the same time. We haven't been down the road since installing the temp gauge so we don't have any history there to compare it to. Planning on a test drive tomorrow.

So, what is the normal operating temp?  None of the alarms went off.

Don and Cary
GMC4107
Neoplan AN340

[CraigC]

Don & Cary
The Allison service namual SA1887D;  sump normal operating range 160 - 220,  max. intermittant sump 250
The Allison mechanics tips manual SA1492; converter-out temp. 180-220 ;  160 - 220 sump normal
GMC Coach maintence Manual C-7713 for P8M-4108A & P8M-4905A; normal operating temp 160; max. temp. 275

You mentioned new oil; A local independent Allison repair shop with 30 years experience as a dealership mechanic only recommends 15-40 for us in the hot San Joaquin Valley because it will hold up to higher temperatures.
My experience with 15-40 over Dextron is my temps. run 10 degrees higher. My normal is 180 to 190 trans. temp. outside temp. can be 70 or 110 degrees.
My transmission runs consistantly 10 degrees warmer then the engine temp. My trans is currently only air cooled and does not have a engine water heat exchanger. IMO there is a great interaction of heat between the engine and trans. moving through the common metal surfaces. Tom C stated in a recient post that the greatest heat load is stop and go traffic, I have seen this in LA traffic & road construction trans. temp at 220, normally idling 5 minutes it will drop 20 degrees or more but not in stop and go a few feet at a time.

Look at E Gauge.com they have a trouble shooting section for gauges. If I remember correctly a bad ground can make a gauge read high.
If your sender is in the pan is there a chance the sender has been damaged during you pan restoration? If you did not remove the sender and hammered on the pan.

[Cary and Don]

The sender is on the "out" line on the Torc Converter.  The test drive sent the temp gauge to 235.  The IR gun said 175.  Since the IR gun reads the same as  the engine temp gauge,  we would guess the problem is the oil temp gauge or maybe they gave us the wrong sender for the gauge. It wouldn't be the first wrong thing they did on this dash. We'll run the trouble shooting from E gauge and check the sender to see if it is the right one.

The transmission shifts a lot better and takes off without the lugging it had before.  The pan was squashed up against the interior filter.  Now it has a lot more room for oil pickup

Don and Cary
GMC4107
Neoplan AN340