Well that makes sense, since the engine is a medium duty truck engine.

 

Last truck ran well over 100K with no heat exchanger and no problem. I did run a huge front mounted trans cooler and 5/8" lines. I say if you want to take it off, take it off. If it scares you to remove it then don't. I've never had a problem with the removal of it, just my .02.

 

apwatson50 and wanna beat me to it... i was going to say


...that almost every car i've ever changed a radiator or timing belt on has had the trans cooler in the radiator, and i actually cut one in half to see just how it works, the one i cut open separated and used just a few passes of the whole radiator, i'd say maybe 6 or 7 if there were 30 total. i think its still behind the garage if so i'll pop a picture up here.

 

If your pulling a heavy load in stop and go traffic theirs not much air flow helping you. Removing it is a no-no if you occasionally get in this situation. Lotsa heat builds quickly

 

i do most of my reasoning based upon the statement "that everything was built for a reason"...
...now that being said, some people have really stupid reasons for building things.

 

long story short...........LEAVE IT ALONE.

 

Poor place for the temp sender. It has no way of telling you actual trans temps. Your reading converter out temps. These will always be way higher than trans temps. 200 degrees outlet temps are normal for a stock Dodge slipper converter.

The high temp sending unit is made to trip out around 275 degrees. It resets at 240.

Move that sender to the return line. That will give you an idea if your coolers are working properly. If you see high return temps. Then its time to up grade coolers. This would also be a good way to test out everyones theory of the "useless" tank cooler. Move the sensor location. Run with the tank cooler. Then remove and see if its doing its job.

Dodge also installed it for cold weather warm up of the trans. With good air to air coolers. A trans will not reach operating temps in the winter. Thats just as bad as overheating one. A trans is designed to operate in about the same ranges as the engine. 180 to 200 degrees.

 

have to agree. its not the heat exchanger its the torque converter thats the problem. Before I swapped out to a much,much tighter converter I could not haul 3 chickens in a wheel barrow with out watching my temps climb faster then obamas budget. now after a full performance build its way better I actually hauled a 7300# gooseneck with a 11,000# john deere 210LE on it through rolling hills this summer and never over heated it was still warm but safe .

 

I have wrestled with this issue over and over in my head. I have a tight transmission and a fairly tight converter (it's no DTT, but it's so much better than stock). I tow a smallish fifth wheel (7000 lbs. loaded) around the mountains of Colorado. Going up the long grades over the passes has given me lots to think about!

My observation is that the tranny temp pretty closely follows the engine temp. (My sensor is in the pan of the tranny, a double deep Mag-Hytek.) I've never really solidly been able to determine if the transmission is heating up the engine or if the engine is heating up the transmission. What I'm beginning to conclude is that the transmission lags the engine just a little on a good climb. So maybe, just maybe the engine is throwing heat into the transmission on these long climbs. At any rate, it's sometimes a struggle to keep my temps down on a 10-mile pull up Monarch Pass, or Vail Pass. I have pulled my radiator out to have it rodded out. But the shop I took it to said it was just fine and he wasn't going to touch it (this after I can peer down into the thing and see mineral deposits starting to form). So... Maybe a new radiator would help my issues, I'm not sure. They certainly do work in concert because it DOES take quite a while for them to cool down going down the down side. And this is after I added an under-bed cooler with fan. I find this frustrating.

My injection pump is only mildly turned up. For those of you with turned up pumps and 5-speeds what sort of temps do you see? If you were to keep it full out, by that I mean the pyro right at 1200* or so, for 10 or 20 minutes (or more) would your cooling system be able to disperse enough heat to keep your engine cool? Anybody have experiences with this scenario with an automatic? I know that mine will not!

I also have some suspicion that the exhaust throws some heat into this sytem since it's so close to the heat exchanger. I've got a Banks 3.5" downpipe and exhaust. When I first got the truck the downpipe was actually resting on the transmission fluid pipes routed to the heat exchanger. That certainly can't help. So relocating the heat exchanger may be an option. BC certainly would have some data on this since I think he's done it.

This coming summer I'd like to experimentally bypass the heat exchanger and see what the results are. I'd love to be done with the heat exchanger mostly because a 4" exhaust is really pushing it for space in that area (and I'm working towards a 4" exhaust). At the least, a relo would help this problem. Maybe I need a valved system where I can redirect transmission fluid flow based on conditions and temperature.

So what I'm saying, is that I've watched my gauges pretty closely for lots of miles under on-the-edge temp conditions, and I have no real sense for what removing the heat exchanger might accomplish.

 

Truckerdee
My son has a 91 5spd with a home made twin turbo set up and its putting down 407 hp/900 tq to the ground I know my 90 (inter cooled) 727 3spd is somewhere around 250-275hp/600+-
and there is no way I can come anywhere near keeping up with him if we go over Donner pass I80 I see my temps get hot and I need to back out and im down to 45 to 50 max pulling 7000 his 91 will pull 10000 at 70 up that grade and his temps run just above normal, my EGTs are at 1250 his are 1100 or less. what I personally feel is that with out lock up the autos generate way to much heat from slippage and we would need 2-3 x a bigger radiator then a stick. my trans guy said that he put the tightest T/C he could get in and it has helped tons ,but nothing like full lock up.
I think Im going to try a under bed cooler to and see how much it really helps,I know my father inlaw 92 auto has a GCVW 22450 and as long as he doesnt push it its fine but its bone stock with the trans cooler
Robert

 

That is absolutely correct. Like was mentioned before, the vehicles is designed as a system, and they work together complementary, one taking up the slack for the other whenever possible, so to speak. This is easier to see in the new trucks with tighter converters, bigger radiators and hotter running engines. The trans in our '07 (48RE) normally runs around 30 degrees cooler unloaded and acts as a big heat sink for the engine. You can see this going up a steep grade on a hot day with the torque converter locked (minimal extra heat being generated by the trans). The trans temp gauge steadily rises climbing grades unloaded, while the engine temp only nudges up a little bit. I'm sure the 727 is working in exactly the opposite fashion in the 1st Gen, transferring heat into the engine coolant.
No, absolutely not. As you know, the mountains here in CO provide the ultimate test for this stuff! I can assure you the radiators in these 1st Gens have a sustained heat exchange capacity for no more than about 250hp max. Notice I said "sustained." I have the truck in my sig tuned to run safe EGT at WOT, sustained. The radiator is the limiting factor. Keeping the revs up and boost in the 20-25 range it will warm up to the high side of the temp gauge in about 10 minutes, depending on the load, terrain and ambient temp. I haven't tried to push it any harder than that, but I am sure overheating could easily be achieved if I wasn't careful.

As usual, YMMV.

 

If y'all want to loose the heat from the Exchanger, just install a quarter-turn ball-valve in the engine coolant line. That way you'll still have it when needing the extra heat input/removal.

 

David, Didn't you move yours. If so where and how hard was it.

 

Is there a larger radiator available for our rigs that is plug-and-play? And if so, does it have the tubing in the bottom to accomodate an automatic transmission?

(I realize this would be a poor substitute for a tighter torque converter; I'm simply curious.)

 

only custom made ones, but I have seen second gen radiators installed with some modifications