buggy trans temp worries

Fordman47201 · Mar 1, 2015

im running a C6 behind my 418 Windsor in my 4 seat buggy , the trans has all the normal buggy upgrades valve body and good internals with a 10" 2200 stall . i am running -8 lines to a large derale cooler with fan that's sitting where its all fresh air no obstructions. i have noticed that it runs hot when im just cruising around trail riding i always make sure im out of the stall speed but am having trouble figuring it out. my only thought is the -8 lines and the large cooler may not be letting the fluid stay in the cooler long enough to cool the fluid . any info or past experience is much appreciated. i love wheeling with the kids but im trying to avoid premature failure .

Chilkat · Mar 1, 2015

What is your definition of hot? I've got a turbo'd 2rz/AW4/D300 1800 stall I think and just put a factory Toyota trans cooler fan on my Tru-Cool trans cooler. The fan runs off the thermostat switch in the radiator. I ran for a while this winter without it and it worked great, but I put the fan on to keep it good this summer and for added insurance. The trans is stock except for the shifters from RAdesigns

Do you have a trans temp gauge or is your fluid smelling burnt or what tells you that you are over heating the trans? I am interested in a higher stall converter in the future like a 2200 RPM like your using.

Fordman47201 · Mar 1, 2015

sorry its running a well over 200 degrees more when its just cruising with traffic. theres no performance issues but i worry about it wearing out too soon. . i am running a set of autometer gauges on everything . i have been told to try to restrict the return side of the cooler to slow the fluid down to let it cool but i figured id ask on here to see if anyone had any experience.

TBItoy · Mar 1, 2015

Re:

Does it have a fan on the cooler?

Chilkat · Mar 1, 2015

Re:

TBItoy said:
Does it have a fan on the cooler?

He say's he's got one

Craig_c · Mar 1, 2015

Inlet fitting on the bottom of the cooler?

I have the same cooler and line size on my Dodge, and it has issues keeping it cool when I'm using the convertor a lot. I Need to do some playing with it to see if I can make it cool better.

TBItoy · Mar 1, 2015

Re: Re:

Chilkat said:
He say's he's got one

I read the post twice and missed it both times! Ha

Maybe check the temps with a IR temp gun to confirm the temps, and see what the inlet/outlet temps are.

Chilkat · Mar 1, 2015

Re: Re:

TBItoy said:
I read the post twice and missed it both times! Ha

Maybe check the temps with a IR temp gun to confirm the temps, and see what the inlet/outlet temps are.

Yeah, seems like more cowbell for the fan on the trans cooler. I don't see how restricting the flow is going to solve any cooling issue. More flow is more better IMO. Gotta get a fan that pushes enough air through that cooler which will take the heat away from your heat ex-changer. Decreasing flow will decrease cooling efficiency. You want the heat out of the transmission as fast as possible, but need the cooler to decrease the fluid temperature faster, seems like more CFM on your fan would be a good start.

I can relate this to my tow pig. I can tow a load @ 60 MPH with the trans staying at about 160 and as soon as I slow down (less air flow through the cooler) it will raise 10 degrees or so for a bit until I speed back up and get some more air flowing through the cooler.

Craig_c · Mar 1, 2015

If the fluid isn't spending enough time in the cooler it can have all the fan in the world but won't pull enough heat out of the fluid.

onepieceatatime · Mar 1, 2015

Re:

Mine 700r4 was getting hot at Harlan this year trying to climb to the top of the mountain because I had it in too high of a gear and it was lugging it. Dropped a gear and it did just fine.

Chilkat · Mar 1, 2015

Seems to me if your putting hot fluid through a cooler and it isn't cooling the fluid then a different cooler might be in order. Check out Tru-Cool. It is quite different than the Derale cooler as the fluid flows through the fins in the Tru-cool where as the Derale's look like the have only a couple of passes with the typical cooling fins.

I only run the tru-cool because my Trans builder told me about the difference between the Tru-Cool and some of the other coolers on the market. His opinion is all I needed because he has a great reputation when it comes to auto transmission knowledge.

*edit* And my trans builder warrantied his work with the cooler even after I told him about the 12k loads I was pulling over the passes in my 93 dodge D250.

TBItoy · Mar 1, 2015

Re:

Also, where is your temp sending unit?

You could be picking up residual exhaust heat and not getting a true fluid temp reading.

Chilkat · Mar 1, 2015

Look @ your fluid, see if it smells burnt or discolored

crawlin85cj · Mar 1, 2015

The fan is moving air from front to back of the vehicle, correct? I have seen fans wired to spin the wrong direction and stall the airflow at the cooler which would be most recognized at cruising speeds.

For what it's worth I run -8 lines through a -10 cooler without an issue. I don't like to see my trans above 180 and it only moves off 160 when pushed hard.

2010 Jim's Garage 4429
2012 Jim's Garage YJ
2013 Wide Open Design WFO

Fordman47201 · Mar 2, 2015

ive checked fan direction and its pulling from the front and pushing it to the rear. ill probable take a temp gun with me Saturday to see what it looks like at different spots. thanks for all the help everybody.

paradisepwoffrd · Mar 2, 2015

Re: Re: buggy trans temp worries

Chilkat said:
Seems to me if your putting hot fluid through a cooler and it isn't cooling the fluid then a different cooler might be in order. Check out Tru-Cool. It is quite different than the Derale cooler as the fluid flows through the fins in the Tru-cool where as the Derale's look like the have only a couple of passes with the typical cooling fins.

I only run the tru-cool because my Trans builder told me about the difference between the Tru-Cool and some of the other coolers on the market. His opinion is all I needed because he has a great reputation when it comes to auto transmission knowledge.

*edit* And my trans builder warrantied his work with the cooler even after I told him about the 12k loads I was pulling over the passes in my 93 dodge D250.

Idk about tru-cool but a plate style cooler is much more efficient than a tube & fin.

paradisepwoffrd · Mar 2, 2015

Re: Re: buggy trans temp worries

Craig_c said:
If the fluid isn't spending enough time in the cooler it can have all the fan in the world but won't pull enough heat out of the fluid.

This isn't correct. To make a system more efficient you increase the fluid and air flow. If you feel toy need more time in the cooler, you need to increase the surface area of the cooler not slow down the fluid.

I suggest taking a read over billvista's cooling bible. While it is for engines, the same physics apply to all fluids.