Best Trans coolers out there??

[Yo Hoot]

Seems my trans is running on the warm side and causing drivability problems.



Once she gets over 235 deg it starts upshifting early and locking up.



What are the best aftermarket coolers out there?

 

[cerberusiam]

You should not be running thise kinds of temps unless you are way over the gross weight, or, running in some extreme conditions. The factory cooler is pretty good IF you don't have another problem.



You have checked flow into and out of the cooler? Removed the check ball from the cooler line? Checked for debris between the coolers?

 

[Bernie]

Removed the check ball from the cooler line?

I'm going to be doing some trans upgrades myself. Where is that check ball? How do I identify it?

 

[Yo Hoot]

I put 65,000 miles on my stock trans with no problems. Ever since the aftermarket worked trans was installed I have temp issues. Is this common?

Should we remove the check ball?

 

[cerberusiam]

I put 65,000 miles on my stock trans with no problems. Ever since the aftermarket worked trans was installed I have temp issues. Is this common?



Should we remove the check ball?

Couple of questions; where is your temp probe? Are you seeing these temps cruisng in lockup or ??? Are the temps the same loaded and unloaded? Are you sure the TC is locking?



An aftermarket TC will kick the tempos up faster in fluid coupling but once you ar ein lockup they should come right back down. I am seeing 180-190 cruising loade dand unloaded in 100 degree heat. I can easily push it to 230 if I mess around power braking or slow speed towing but they come right back down in lockup.



Here is a pic of the check ball and its location on driver side of truck at the front of the engine bay.



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[Yo Hoot]

I don't have a gauge on the trans but I used a IR gun on the pan when it started acting up. I was getting 200-205 on the hottest spots. I was told by someone else that they got 237 on the scan tool when their pan IR'd 200.
Temps do come down after lockup but not enough to stop the weird upshifting. Once in a while it will cool down enough to shift normally.

With the stock trans I never had any drivability issues so I never thought about adding a trans temp gauge.

With the new trans the heat went up and the strange shift behavior over 230 degrees cropped up.

I guess it's time to order a temp gauge.

What really bugs me is why the thing upshifts and locks so soon at 230? Nothing documented says it's supposed to act that way.

We changed out the temp sensor, the shift position switch and the whole valve body. No difference. We think it's the TC.

The check valve is untouched, stock. Should I check it? Keep in mind there were no trans failures on this truck so I don't think debris is a issue.

What is it about a TC design that might make it generate excessive heat? On the other hand, what might be the issue with my trans cooling system that causes it to not cool enough? I had a bug screen on the front of the radiator but it made no difference after removing it. The whole radiator cooling stackup is clean.

 

[cerberusiam]

The check valve is untouched, stock. Should I check it? Keep in mind there were no trans failures on this truck so I don't think debris is a issue.



What is it about a TC design that might make it generate excessive heat? On the other hand, what might be the issue with my trans cooling system that causes it to not cool enough?

The check ball is there to keep drain back from happening when the truck sits. It is also a flow restriction and a garbage trap. If you have a custom VB it more than likely will charge the TC in park and circualte the fluid so the check ball is now not needed.



The cooler return is used in the shafts and drums for lube and cooling then into the pan. Its either coming bacl too hot or there is a problem in the trans that is causing too much heat.



If the TC is too tight or not put together quite right it could cause too much fluid shear and drive the temps up. If the temps drop back close to normal when you are cruising in lockup then I think the TC may be the culprit.



The funny shifting could just be the viscosity dropping enough the fluid is easier to push, or, it could be the ECU saying "things are warm lets get into lockup". I have heard others reporting the same thing on stock transmissions so its not particular to yours.



If it was me, I would start taking temp readings in the hot cooler line, the return line, and the pan and see if there is anything obvious. I would remove the cooler line check ball just to eliminate a possibility of partial plugging.



Thats my . 02, good luck.

 

[Yo Hoot]

Thanks for the advice. I installed a fan powered trans cooler today. It has the same big lines with full dia fittings so I don't think there is much of a flow restriction. It's a flat plate cooler with great flow characteristics.



After the test drive it did take a lot longer for it to start the premature upshift/lockup but it finally did happen. It doesn't do it as abruptly and it goes a way sooner if I stop and put it in park.



Next I'm installing a temp gauge and a double deep pan.



How do you remove the check ball? Does it fall out when you unscrew the fitting or is there more to this?

 

[cerberusiam]

How do you remove the check ball? Does it fall out when you unscrew the fitting or is there more to this?

Yes, the ball fitted in the fitting that comes out of the line. Take a drill and punch and destroy the ball to get it out of the fitting.

 

[Yo Hoot]

I drilled it out today. There also is a flow restrictor in there. That came out too. I am willing to bet the flow restrictor is there to slow the fluid down some going through the trans cooler so more heat can be pulled off on the way through. Removing it could be a bad thing.

BUT>>>>>>

I took it for a test drive. Temps dropped 15 degrees and didn't spike.

I installed a fan powered aux trans cooler yesterday. That helped some but not entirely. Some have said an aux cooler adds restriction. This one has full 1/2 bore fittings, large hose and volumous flat plate design so I do not believe it adds much restriction at all.

It held the heat back better than without it but I still got the heat spike, it just took longer to get there and went away sooner.

This morning I did the check valve (drainback valve) and took it for the same ride that I know make the trans hot and causes it to shift goofy.

Looks like it's holding cool now. I can't say for sure cause it's only one day. I'll see haow it goes but I'm definitely getting to the point where heat is not going to be an issue.

I'm thinking from an engineering point of view that the flow restriction in the front cooler cause by the valve may be holding fluid in the converter too long which cause it to soak up too much heat before leaving the trans. By providing more flow, the heat is being drawn out of the trans at a lower temp an is able to be cooled easier.

Also by removing restriction up front at the stock cooler it should negate any restrictions added by the rear aux cooler.

 

[Ducman82]

what is the point of removing the check ball? why is it there?

 

[TCDiesel]

The factory system should Not be tamper with, It is designed to Cool in the summer Heat as well as warm in the winter Months. I would check the return line with a inferred temp gun, follow it as far as possible back to the trans, if the temperature starts to rise as you get closer to the trans housing than you have some type of internal Problem, Pump, some type of restriction, etc.

 

[Yo Hoot]

Geeze isn't that the same as saying don't mess with the stock transmission?

 

[TCDiesel]

Hmmm,I have yet to see a aftermarket system ( Auxiliary Primary Cooling/Heating) that is combination road and off road use that is superior to the Factory setup, I have install many and seen hundreds more Built transmissions from many Builders that improve the life and operation of the unit. When cold temperatures arrive by tampering with the bypass back to the Primary cooler/heater the trans may not shift properly.

 

[Yo Hoot]

There is a separate thermostatically controlled bypass valve in the top of the cooler. I did not tamper with that valve. We aren't talking about changing entire systems here. We are talking about tweeks that make enough difference to make the trans run cooler but still have the heating portion of the system intact.

 

[cerberusiam]

what is the point of removing the check ball? why is it there?

The check ball is there to prevent converter drain back and the infamous "put it in gear and no go" when the truck sits for a bit.



Stock the converter does not charge and circulate fluid in park you need to get fluid circulating before the truck will move some times. Most aftermaket VB's and shift kits fix this so they are superfluous with modified pieces.



As is, I suspect, the flow restrictor. These 2 combined with the increased line pressures and tighter converter dump too much hot fluid back into the trans instead of letting it circulate and cool. With the increased pressure the addition of a secondary cooler should NOT impact the flow. I would not advise the extra cooler with stock pressures but higher line pressures I believe can drive moderate sized add on cooler if needed.



The flow restrictor may also have something to do with the recirc capabilites of the fluid to fluid cooler when the fluid is cold but loosing that should not be a problem as the tighter converter and higher pressures are going to provide more heat faster.



Yo Hoot, glad its looking like you found a solution.

 

[Yo Hoot]

Thank you cerberusiam! You really helped me out here.

 

[TCDiesel]

I guess I should ask? are we talking about the thermostat or drain back Valve? In Pic 1 is the Thermostat.

 

[TCDiesel]

Ok, My mistake Sorry for the confusion.

 

[Yo Hoot]

No problem and I agree it's good to leave the thermostat alone. I couldn't find a picture of the drainback valve in the service manual. They talk about it but that's about it.