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Discussion Starter · #1 ·
All, just wanted to post my transmission cooler install. I think it's just unique enough to not be a duplicate post of commonly installed transmission coolers for the TBSS.

I used a Tru-Cool 40K, an Improved Racing ENV-170 thermostatic fluid filter with 165-degree thermostat, a Wix 51622 filter, a bunch of AN fittings, and 3/8 braided hose. The setup bypasses the factory transmission cooler entirely. It's overkill, unnecessary, difficult to install, too darn expensive relative to virtually every other option, and I installed plenty of additional leak-points/points-of-potential-failure. I know, well aware. It's not the best or worst idea, just what I wanted to do on my car and I'm posting it as an FYI.

A few notes.:
I did trim some plastic to clear the cooler lines and I had to get a little crafty bending the hood latch support bar to fit the cooler as high as I could get it. To bend the latch support, I used a bending brake in my 20-ton H-frame press.

The thermostat does what it's supposed to, with the exception some fluid is always traveling through the cooler by design, the fluid doesn't start primarily flowing through the cooler until the temperature at the thermostat gets into the low-160s then the fluid doesn't get above about 170-degrees. I haven't yet pulled a heavy load up a steep grade but I'm safely betting the cooler will be fine.

The OBD-II transmission temperature sensor via an AeroForce Interceptor reads about 25-degrees warmer than the pan temperature. I haven't explained this one yet, but the 170-degree reference above is from the pan, not the OBD-II port.

There is a chance that I will loop the factory "cooler" back into the mix because it takes 12-14 miles to warm the fluid past 160-degrees and most of my trips don't last that long, and I think my fluid is too-cool-too-often. The factory "cooler" performs a warming function after the engine coolant thermostat opens and would help get transmission temperature up to 160-degrees faster then the transmission cooler should still be plenty big enough to keep the return fluid below or around 170-degrees like I have today.

If I had to do it again, I probably wouldn't have used hard line above the cooler and I would run braided hose for everything forward of the splice to the factory hardlines. I would also not use unions where I could have waited for and bought braided-hose-to-male AN flare fittings . The original design was largely hard line then I changed course mid-project.

There is a boat-load of discussion surrounding the perfect transmission temperature and what you do and don't need for a transmission cooler, this thread isn't intended to spark mass debate.

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Splice to factory hard lines immediately forward the front passenger axle shaft.
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Looks great!

As you said definitely overkill and lot of potential points of failure / leaks.

Two thumbs up for out of the box creativity.
 

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Discussion Starter · #4 ·
Thank you. Will do on the follow-up. My guess is there will not be much of anything notable unless the transmission explodes, then that filter will save me from debris getting into the cooler—which I never want to have to remove… ha.
 

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Is the cooler not mounted more or less flush to the radiator? I'd think that kind of proximity you could get some level of heat transmission to warm it up some?
 

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Discussion Starter · #6 ·
The cooler is spaced off the air conditioning condenser ~1/4”, not directly off the radiator. Even if I was getting proximity heat transfer, with my fluid thermostat, the cooler is largely bypassed, 95%+ IIRC, until the transmission fluid temp increases enough to open the thermostat and redirect fluid to the cooler versus looping back to the transmission.

I need a fluid heat source between the transmission output line and my thermostat/filter. The factory heat source is the “cooler” integrated into the radiator which becomes part of the game after the coolant thermostat opens.

After dealing with the winter thus far, I’m sure in the spring I’ll reroute my cooler lines to loop the factory cooler back in. I’ll roll the dice I don’t end up with a coolant leak into the factory cooler because I have to baby it wayyyyy too long waiting for the fluid to warm up enough to drive with any sort of enthusiasm.
 

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Ah, that's a fair point. Maybe run a small cooler attached to the radiator that bypasses the thermostat?

Or, skip the thermostat all together, sounds like it's causing more trouble than anything.
 

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Discussion Starter · #8 ·
I don’t think we’re on the same page yet. The 165-degree transmission thermostat is there to bypass the 40k cooler until fluid gets warm enough to need to be cooled. If I bypassed my transmission thermostat, I’d go from having a temporary problem of needing 12+ miles to warm the fluid enough to I’d never get warm enough, especially in the winter.

The issue is not the transmission thermostat. The issue is the fluid is too cool for too long before it gets warm enough to need to flow through the 40k cooler. One reason it takes so long to warm up is I no longer have the factory radiator cooler heating the trans fluid after the coolant thermostat opens.
 

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No I get that, but what I was thinking is you might pick up more heat by at least running the fluid through the engine bay and near the radiator than just keeping it all stuck in the transmission basically. Spit balling more than anything, just thinking if you could get the fluid into the engine bay you could warm it up a little faster. Maybe some sort of micro cooler near the exhaust to warm everything up? Big enough to add some heat when cold, but small enough to not be noticed when the larger cooler kicks in.

I've been thinking I'd bypass my radiator trans cooler when I add my external trans cooler, and so I'm thinking out loud for myself too, lol.
 

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How much was just the cooler kit with barbed brass fittings and mounting hardware? I see that type cooler on Amazon lately for about $69 & free shipping for generic brands. I bought all the ACDelco steel lines but I'm thinking of using aircraft fittings and braided stainless hose instead. Thanks.
 
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