Bypass cooler? Radiator fitting interchange?

[TheBac]

Mike, two questions:

1) Is it ok to bypass the trans cooler in the radiator tank and just use the trans cooler in front, or will the trans have overheat issues just using the one cooler? (I plan on using yours or the earl's).

2) Are the radiator trans cooler fittings in an 1500 gasser radiator the same as in the 2500 diesel radiator, and if not, can they be interchanged?

Thanks.

 

[dracing70]

I was told it would overheat, thats why i worked so hard to maintain utilizing both coolers with my setup. I had to relocate the front cooler and just found it much easier to change everything to an fittings. I just used 10 an with 7/8-14 o ring on the radiator cooler. U can use jic hydraulic fittings or take apart the beveled washer from the stock fitting and use it with a standard an o ring fitting.

 

[THEFERMANATOR]

The 1500's cooler is DRASTICALLY smaller than the 2500HD's with an ALLISON, even the 2500HD with a 4L80E uses a smaller cooler in it. And you could get away with a external cooler so long as you put a fan on it to keep it cool during slow speed driving when airflow isn't there to keep it cool.

 

[TRUBBS]

i thought the radiator core was to HEAT the trans fluid? to keep the atf at the temp it needs to lockup ect....?

(im probably high in the night and all tho so dont mind me)

 

[lts1ow]

i thought the radiator core was to HEAT the trans fluid? to keep the atf at the temp it needs to lockup ect....?

(im probably high in the night and all tho so dont mind me)

Thats what I always thought, on my race car the trans is usually cooler than the engine temp.

 

[Mike L.]

The radiator heat exchanger is there for both the above mentioned reasons. Below 30 mph there is no airflow so the trans will run very hot. The heat exchanger in the rd will do the initial heat knockdown and the external cooler will do the rest. Preheating the fluid is necessary in cold climates and the heat exchanger handles that problem as well.
If you decide to only run the outside cooler you will have to run a big fan on it and have it activate on startup. If you use a thermostat it may not keep up with the heat as the electric fans don't play catch-up very well. I tested this stuff out in the desert years ago. I first used a thermostat to activate at 180F. ( they are not accurate ) In 100F heat, when the thermostat kicked the fan on; the temps never came down enough to satisfy me. My next test was to activate the toggle switch overide on start up, and the temps stayed cool.

 

[TheBac]

I suspected as much. Thanks for the info.

 

[TheBac]

The 1500's cooler is DRASTICALLY smaller than the 2500HD's with an ALLISON, even the 2500HD with a 4L80E uses a smaller cooler in it. And you could get away with a external cooler so long as you put a fan on it to keep it cool during slow speed driving when airflow isn't there to keep it cool.

Are you 100% sure of this for the 99-up trucks? I ask because I compared the two radiators, same year, 1500 LS to 2500 Dmax....it looks like the tank sizes have the same widths/depths (albeit the Dmax is 2" taller) and the two trans heat exchangers are both 7 plate, 11-1/2". It looks as though the fittings can be interchanged, too, as they use the same 3/8NPT threads?
Dmax: http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=NRS2986_0237460145
LS:http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=NRS2819_0352013394
Even if the gasser radiator h/e is not as efficient as the Dmax (due to core size?), couldnt I still get away with using it, plus using a fan/cooler setup in front to offset any inefficiency?
Remember, this isnt for a DD truck. Its for my 1/2 ton racer swap.

I do appreciate the help, as always.

 

[sweetdiesel]

if its not for a daily driver just use a w/a trans cooler.

chisled makes them and for the price u wont beat it getting any other cooler

 

[THEFERMANATOR]

Are you 100% sure of this for the 99-up trucks? I ask because I compared the two radiators, same year, 1500 LS to 2500 Dmax....it looks like the tank sizes have the same widths/depths (albeit the Dmax is 2" taller) and the two trans heat exchangers are both 7 plate, 11-1/2". It looks as though the fittings can be interchanged, too, as they use the same 3/8NPT threads?
Dmax: http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=NRS2986_0237460145
LS:http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=NRS2819_0352013394
Even if the gasser radiator h/e is not as efficient as the Dmax (due to core size?), couldnt I still get away with using it, plus using a fan/cooler setup in front to offset any inefficiency?
Remember, this isnt for a DD truck. Its for my 1/2 ton racer swap.

I do appreciate the help, as always.

The trucks with an ALLISON use -10 7/8"X14(5/8") threads from 03+, all of the gassers I have seen use the much smaller 3/8" lines.