Auxiliary Transmission Coolers

[Richyrich]

hopefully you guys don’t mind me jumping on this thread . Only relevant one I could find.
is that a transmission cooler behind the grill there?
is the fact it is slanted a bad thing?

I might buy this jeep next week and have not seen in person. Want to make sure it’s not a problem and my knowledge of these is only what I’ve read on this thread. THANKS.

 

[toximus]

is that a transmission cooler behind the grill there?

Yes.

is the fact it is slanted a bad thing?

It's probably not mounted securely and shifted around.

 

[Richyrich]

Yes.



It's probably not mounted securely and shifted around.

Thanks for the quick reply. That knowledge will definitely help me when buying.

 

[Crunchy]

Im thinking about adding this PSC setup. Has anybody tried this? Just curious how much extra temp drop you see with that setup?

 

[Eddie Greenlee]

When you say monitor the trans temp, would that be with a bung into the pan? I've been debating mounting a sensor in the pan vs on the return line after the cooling system, or maybe both with a toggle switch.

As for where to mount the cooler, my understanding is that the best place is after the radiator going back into the trans. If there's heat soak then the aux cooler will help take care of that, and if it's winter then you want the radiator there to warm up the fluid to operating temp. The aux cooler has a bypass for when the fluid is already cool so in winter it shouldn't over-cool during warm up.

What aux cooler has a bypass for when temps are already cooled to a certain temp ??

 

[Eddie Greenlee]

You want to know how hot the transmission is. Not how hot the cooled or heated fluid is, how hot the trans is.

So exactly where do you place your temp sensor to measure how hot the trans is ?

 

[Eddie Greenlee]

There is no aftermarket radiator that is regularly recommended by anyone with any experience. Personally I'll stick with the tried and proven Mopar which outcools anything we're aware of that sells for a reasonable cost. The OE Mopar radiator has sufficient excess cooling capacity to keep the engine cool in the hottest desert conditions, something few aftermarket radiators can match.

Jerry, are there aux coolers out there that bypass the fluid if the fluid is already cooled enough to run the automatic transmission at the right temps ??

 

[mrblaine]

What aux cooler has a bypass for when temps are already cooled to a certain temp ??

I think I have seen a cooler before that had it built in but most do this instead.
https://www.summitracing.com/parts/...MI2YH6uLCF8AIV4SCtBh3dnwO4EAQYBSABEgIYk_D_BwE

 

[Eddie Greenlee]

I think I have seen a cooler before that had it built in but most do this instead.
https://www.summitracing.com/parts/...MI2YH6uLCF8AIV4SCtBh3dnwO4EAQYBSABEgIYk_D_BwE

Well that’s pretty cool. Hopefully it’s not just another maintenance part.
have you ever used one?

 

[mrblaine]

Well that’s pretty cool. Hopefully it’s not just another maintenance part.
have you ever used one?

No need, they are for areas where it gets cold and the trans needs to be warmed up to operating temp.

 

[MountaineerTom]

What aux cooler has a bypass for when temps are already cooled to a certain temp ??

I have this B&M cooler . B&M 70264. In their description, it says this:

"The unit monitors resistance to flow by allowing a controlled amount of ATF to pass through a self-regulating orifice. Controlled by viscosity, thicker ATF is returned directly to lube through two bypass openings in the stacked plate core, while thinner ATF is directed through the core to cool as operating temperatures increase."

I think this might be what your saying.

 

[Eddie Greenlee]

I have this B&M cooler . B&M 70264. In their description, it says this:

"The unit monitors resistance to flow by allowing a controlled amount of ATF to pass through a self-regulating orifice. Controlled by viscosity, thicker ATF is returned directly to lube through two bypass openings in the stacked plate core, while thinner ATF is directed through the core to cool as operating temperatures increase."

I think this might be what your saying.

That great ! That two great ways! Thanks

 

[mrblaine]

That great ! That two great ways! Thanks

Just how cold does it get in Mississippi?

 

[Eddie Greenlee]

Just how cold does it get in Mississippi?

Well nothing like up north but Nov - feb it can be anywhere between the teens to 60. Ya never know. So compared to up north not very cold. We just have humidity and that makes it feel really cold at times

 

[Eddie Greenlee]

I guess I’m really more worried about the heat.

 

[Rusty762]

I have been running the Derale unit with fan that Jerry has, its mounted under the rear of the tub and kicks on at 185 which happens on any kind of grade. I have seen consistent tranny temps in the 240-250 range. The bung is in the pan, might try the autometer gauge Blaine listed just in case the gauge I have is defective which I doubt. I think there is not enough airflow with the current location and since I am running a PSC hydro assist have been looking at the dual PSC setup. Does anyone have feedback on this setup?

https://www.polyperformance.com/psc...CKnjgzbrk-WMuL9ICXLtYHA9hgiI9a5saAlLYEALw_wcB

 

[Rusty762]

Im thinking about adding this PSC setup. Has anybody tried this? Just curious how much extra temp drop you see with that setup?

View attachment 224970

Did you ever get any feedback on this setup? I am leaning this way as I have the PSC hydro setup and the Derale finned cooler which sits dead center of the radiator. The Derale unit for TJ's with a fan is so far under the frame it gets no air flow.

 

[Moglocker]

Did you ever get any feedback on this setup? I am leaning this way as I have the PSC hydro setup and the Derale finned cooler which sits dead center of the radiator. The Derale unit for TJ's with a fan is so far under the frame it gets no air flow.

Isn’t that why it has its own fan?

 

[pagrey]

I have seen consistent tranny temps in the 240-250 range.

240 is overheat shift schedule on the 42RLE, something doesn't sound right. With a cooler your pan temperatures shouldn't be that high. Are you sure your lines aren't kinked or blocked?

 

[Irun]

Did you ever get any feedback on this setup? I am leaning this way as I have the PSC hydro setup and the Derale finned cooler which sits dead center of the radiator. The Derale unit for TJ's with a fan is so far under the frame it gets no air flow.

I've run the B&M cooler @MountaineerTom posted in three Jeeps now with great luck. Before I installed the cooler I had transmission temperatures consistently north of 220° when wheeling. After, the highest temperatures I've seen were around 186° on a long slow (4:1) steep hill climb. It is paired with a single pass Derale, for cooling power steering fluid.

https://www.summitracing.com/parts/bmm-70264