Is the pump turned up because mine is and if I push it hard on hills it will get warm on me but flat ground is just fine so that makes me think the pump has been turned up.

 

If it's a stockish dodge trans setup it will have 2 or 3 trans coolers. The two it will definitely have are tied into the engine cooling system. There are lots of heating/cooling issues associated with the early Cummins/727 combos in the Dodge. The Gear Vendor makes me suspect it is contributing and this is the config you have. Need to figure out what you have and how it is set up before we go any further.
That would be incorrect
He doesn't even know for sure what trans is in it yet.
The transmission shares the cooling system with the engine is a stock 1st Gen setup. Funny you own one, but don't seem to be aware of that.

 

The engine can run WOT at full load all day long as long as nobody has played with the fueling. More fuel= More heat= Overheating, Meltdown

Depending on what kind of cooling system the trans has I would say they both man & auto could cause an overheating condition.

Manual has no give and loads the engine harder causing it to work harder and produce more heat.

Auto can have no affect unless it has an oil to water cooler like the 1st and 2nd gen Dodge cummins do. The engine's cooling system can only dissipate so much heat from the hot fluid before it starts to rise to match the trans fluid.

It sounds like you have a combination of high egt's and an undersized cooling system. You need to find out if the egt probe is in the manifold or the down pipe, there is a 300 degree difference in location. When you said 900f at 25-30lbs of boost that sounds about right if the probe is in the dp,900f+300=1100f. My '93 will heat up to around 210f-235f up long grades doing the same boost and 1100-1300f in the manifold. I would get a transmission fluid temp gauge and find out where your pyro probe is and go from there.

 

"If it's a stockish dodge trans setup it will have 2 or 3 trans coolers. The two it will definitely have are tied into the engine cooling system. There are lots of heating/cooling issues associated with the early Cummins/727 combos in the Dodge. The Gear Vendor makes me suspect it is contributing and this is the config you have. Need to figure out what you have and how it is set up before we go any further"

I believe this is a chevy repower, not a Dodge

Sure sounds like cooling issue, to small of radiator or bad water pump. I would think even if the tranny is slipping, it shouldn't cause the engine to overheat. If the tranny fluid gets over 300, the tranny will fry cuz the fluid starts to burn. Good luck

 

true, but it is easier to make the Cummins engine and Dodge transmission (TF727) from a donor 1st gen Dodge truck work with a GV unit in a Chevy truck than to build up a chevy trans and adapter and converter to mate up and work with the Cummins motor. I see many converted trucks this way. they already have to build a new drive shaft so modifying a tranny crossmember that will have to be modified anyway to level the motor and make the correct mounting points and driveline geometry is a piece of cake to a builder.

they could have used the dodge radiator or the chevy one. Both IIRC have the built in tranny cooler and can / will add to engine heat. make sure the fan clutch is working, nothing is plugging up the cooling fins in the Rad, and that it has atleast a 3 core radiator. you might could put an Aux cooling fan but it sounds like you don't have room due to other coolers in front of the radiator. this makes me wonder if you have adequate air flow across the core..... is there a fan shroud on the truck? this will make or break the effectiveness of a fan.....

 

How hot is hot? What gauge are you reading the temps from?

I bet its a combonation of a few things... Including a hot tranny.

 

This ^ ^ ^ is why I suspect the trans is driving the problem. But like you said, without some of our questions answered, we are just guessing.

 

Check your fan clutch.

 

I still want to know if the pump is turned up because I think that is whats doing it because my 92 dodge does the same thing and I have put a new clutch fan and thermostat and an extra trans cooler on it but if I hit a grade and push it hard it will climb pretty fast.

 

It's been my experience that extra weight and a 1st gen cooling system in big hills are not the best combinations.
Even an early 2nd gen with a massive aluminum radiator has problems.

I've played the game before.

Used to pull a 40 foot 2-car trailer with 2 fullsize Chryslers through Colorado and it would overheat every time.
I changed radiators, cooler thermostats, hotter thermostats, new clutches, heavier fan clutches, you name it, I tried it. Numerous times.
It was an untouched 1stgen with a 5 speed with 4.10 gears.

The problem is the RPMS are too low to puill the load and cool the engine in a higher gear, gearing down increases the air flow, but slows ground speed and below 45mph, the fan cannot pull enough air for the work the engine is doing.
In the end it always comes down to having to pull over and cool it down.

Strangely enough, the later, higher horsepower (more fuel) trucks seem to have a better time of heavy loads and hard hills, possibly because they make more horsepower more efficiently in the optimum RPM band.
They also have larger, more efficient cooling systems.

Mark.