Well, this is interesting: Bought this truck and pulled my 5er to Mexico and back no issues. In December. Never noticed the temp gauge moving much above the 1/4 mark. Just a bit on the hills. Had the radiator serviced for summer. Tech said a TON of crud came out of the (probably bone stock) radiator. Now, its 100 degrees here in Arizona typically. Was towing my flatbed trailer with the Massey Ferguson 245 (heavy lil' tractor) to NM and gauge went up to the 3/4 mark climbing long grades into Flagstaff and north of Santa Fe. Was at the point where I said to myself, one more tick up and I have to stop. Cools right off down the hills. The shop put a new thermostat in when they serviced it and there's definitely different temp behavior. Old thermo took forever to warm up in winter. New one goes straight to the 1/4 mark on the gauge, then to half after a pull uphill, then 3/4 under load up a steep grade. Also, doing only 40 manually dropped out of 3rd with the auto.
Is this NORMAL summer temp behavior? I hate to watch that gauge climb. Normal? Fan clutch?? Leak? Thanx Gents. H.

 

that's actually within the truck's normal operating temperature range.

 

When the temp gauge gets up to the 3/4 mark pull over shut the engine off and see if the fan clutch is locked up. Mine had some resistance but not a lot and a new clutch keeps my gauge at 1/2 or less even on hot days working the truck.

 

might be worth checking that the new t-stat is Cummins, .... you likely know the generic ones are MUCH cheaper but just don't work worth a hoot in our engines, don't ask me how I know.

 

That sounds within the normal range to me too. Wanna diesel has a pic of the gauge with the "normal" range added with orange lines iirc. Maybe somebody else has it.

 

I bet the load you were pulling is half again as heavy as the fiver. Tractors are heavy - campers are toothpicks and tinfoil!

 

found it!

 

M1 Lover it's normal.

 

Mine operates in the same temp range as yours. Loaded or empty the gauge runs at 1/2 but loaded it will go up to 3/4 or maybe a touch higher. The hills we have are not near what you have. Ask the shop about the T-stat as ppiggppenn said and see if its genuine cummins. I had issues with a generic one, it would run cool then under a load it would heat up quick. But yes check the fan clutch ect for other probs. With the auto maybe add a extra cooler to take some of the heat away from the radiator. Good luck with it.

 

Can you hear your fan Roaring when it is hot or is it running quietly?

Do you happen to have the optional Under Bed Cooler?

I am with Dave, bet your load is heaver than you think it is.

Jim

 

In 105* temp pulling a 15/16000 lb tractor on a 32' g/n my 92 with the auto the temp will get up to the high mark in jimbo486 pic above. But my fan clutch is good and I have 2 big tranny coolers w/fans. I'm guessing the MF245 weighs in around 8/9000lbs max with weights n water. Check your clutch fan, i replaced mine with a off the wall brand and it lasted maybe 2 months, the one i have now came off a spare engine i have but works great. "I looked up your shipping wt. for the 245 and it's anywhere from 3900 to 6150" this should give ya an idea what your up against.

 

- campers are toothpicks and tinfoil! [/QUOTE]

Ha! And when they are rolled over at highway speed, it is spectacular!
Think "Mythbusers" and a Bomb!

 

Hey Gents, THANX for the replies. Good to know that I wasn't asking the Cummins to do anything it couldn't handle. Good advice ALL.
YES, my truck has that mongo under-bed tranny cooler. YES, I'm sure the shop put a Checker thermo in it.
Besides the darned Dodge Dealer, WHERE can I get a gen-yoo-ine Cummins thermostat and fan clutch??? Next question: Is 40 mph up a hill with a big load tops for a stock truck? I dropped it down into 2nd and it seems to govern out at 40 mph. I'm running a brand new fuel filter BTW and have removed the stock muffler..... Hunter

 

Cummins would be a better deal than Dodge.

40 sounds about wound out in 2nd with the stock governor spring.