Trans Cooler added but took no Fluid

I have a 2021 and added a trans cooler using the OEM Thermostat Puck, OEM hard lines and Hayden Cooler.

I added 2 quarts of WS and started the truck shifting through gears while waiting for trans pan temp to reach temp for level checking. Left the pin in the thermostat puck while all this was going on. Pulled the check plug at 105 and all but about 1/4 of the 2 quarts drained out before I got a trickle. Made no sense to me.

Left the pin in and started test driving and temps for TC and Pan stayed below 190 for many miles with hill climbs.

A few weeks later I noticed some strange behavior in shift to 2nd gear where it felt like it would stumble and then come back.

Talked with my tuner and he did not see any strange behavior in fueling.

Today I plugged the OBD Fusion back in and monitored trans temps on my drive home from work. Pan temp never went above 185 but I would see my TC temp jump as high as 224. 40 degree delta between the two temps seems off to me.

Waiting for everything to cool off and going to try and add oil and re-do the level check.

Anyone ever seen where the trans didn't take as much oil as expected after adding a cooler? Did it just need more time to push the air out if the empty cooler and lines???

Is it normal to see periodic temp delta of 40+ degrees between TC and Pan?

 

Also wanted to mention I did a drain and fill on trans a few weeks before I added the cooler and the level check went as expected so I have to believe I was not overfilled before I added the cooler kit.

 

How many miles on it?

 

55K. Did the drain and fill at 53K. Added the cooler a couple thousand miles later.

Also added supercharger about 10K ago.

Very rarely tow a motorcycle trailer or have a dirtbike on a hitch rack so does not really get pushed that hard

 

Curious about the level on the 2nd check.

 

I know many recommend adding an extra half to full quart past the trickle level, including IPT transmissions.

 

I've seen 40 degree split between the two with GCS system mainly towing up hill and torque converter not locked. I've never had a stumble or recall how much came out after cooler installation. I just figured check at correct temp and trickle it was good to go.

 

What's the capacity of you cooler? If it's only half a quart then that might have been correct. Also what's your definition of a trickle? To me is as soon as the fluid starts does the side of the pan rather than down in a straight line. Btw you can crack the check plug at 99°. The range is 99-111

 

Me too. Takes forever for the trans to cool down

 

I have started to read the same and my Tuner also says these trans like to be a little on the full side.

 

Very smart question asking about volume capacity. I have a Hayden 689 but not seeing those specs shown. Will keep digging. I also plug it up as soon as the outflow starts to wick along the side of the pan but still flowing.

 

Man, this is why I love this forum. Can always count on quick and helpful responses and questions I hadn't considered.

As soon as the trans temp cools to where I can actually start it for a minute and run through the gears, I will be checking it again. Plan to just add a 1/2-1 qt and do the level check and maybe I'll use the other 1/2 to do a small overfill.

Thanks again

 

Truck sitting for 4 hours. Just added a quart and connected to OBD only to find it's still 120F.

 

Ok, i waited until it was around 85 and started her up. Banged through gears till I saw 99 and then jumped under to pull the check plug. Same deal...pretty much the entire quart came back out before the drain slowed. Plugged everything up and added a 1/2 quart.

I'll continue to check trans temps but it still bothered me that the TC temp would spike super quick and then dump back down just as quick, while the trans temp stayed pretty stable. Maybe that's just how it behaves???

 

A few things to ask.

1) recently added a supercharger: what is your driving style? Are you making 0-60 passes at every stop light? That'll do harsh things to a transmission with a power adder.

2) 40* splits isn't far off if you are constantly in/out of TC lock. I can see this being done in hills, while towing outside of 4th, or goosing the throttle to hear the SC sing.

3) you have mentioned your tuner a few times. Fueling looks fine, but based on what? Do you have logging capabilities that you can keep running while driving and then save and note the time of the shudder?

4) there is a fluid degradation reset process if you are swapping out more than 50% of your fluid at one time. Have you tried that? It's done via tech stream.

https://www.tundras.com/threads/20k-and-atf-degradation-65-000.133087/#post-3380275

5) you can also look up/monitor your value via your choice of monitoring tool. It's under the Toyota PID package.

6) you can also try to disconnect your battery for 30 minutes or so in hopes of resetting the computer, though I'm not sure how much it will help.

I'm sharing all of these things since you seem to have tackled the fluid level part.

 

That's completely normal. The TC out measurement is just checking that bit of fluid exiting the torque converter before it goes to the cooler. It will get hot very quickly due to the TC being unlocked and the speed differences between the stators caused by the load. Once the TC locks and/or the stators get close to the same speed, the temp drops quickly. The reason the pan temp doesn't react to quickly is you are measuring quite a bit of fluid. It takes some time for that heat to make it to the pan... but also remember the fluid leaving the TC is headed to the cooler first, so it's cooled before it hits the pan.

This is why i just monitor pan temp, the TC out temp can very greatly based off load and lock-up. You really only need to monitor it to compare it to the pan temp to monitor lock-up. When the two temps match or come within ~2F of eachother, you are in lock-up. Or you just use a different PID to say if lock-up is on or off.

 

1. No, not racing light to light. Over taking people on the highway or in traffic. Only full pulls from a stop have really only being for logging purposes for the tuner. For the most part most of the supercharger load is when I'm doing my 1000ft climb to my house at the end of my commute.

2. This is not me. I live in Silicon Valley and in shit traffic most of the time until I get to the mountains on my way home.

3. I can log with VF Tuner and laptop on my console and easily start and stop the logging since the behavior is pretty predictable. That said, I think the issue is in the tune because I reverted back to my last tune from previous tuner that never had this condition and it went away. Either way, the 2nd gear stutter is definitely in the tune.

4. I have only done one spill and fill at 50K miles. Only other fluid was just adding for the cooler and that spewed out.

5. This is what I'm using to live monitor Trans and TC temps on my truck display through Apple Car Play. TC values definitely jump quickly on acceleration and decelaration with downshifts but quickly restore. I'm just shocked at how quickly it will jump 40 degrees and jump right back down again after I remove the load.

6. I am constantly loading and changing tune files so I think that triggers ECU resets. But, I also recently replaced my Battery so that caused the reset as well.

Thanks for the response and all the info

 

Orientation of the cooler can be a problem depending on the design. Sometimes a big air bubble gets trapped inside them when the orientation doesn't allow for proper flow.

 

Thanks, this is helpful

 

I am using a Hayden 689 and Mounting Plate from Jmunk here on the forum that several have used. But I can honestly say I didn't really pay much attention to whether the outlet is on the top or bottom because it seems like a topic several have asked about but there is no general consensus that I saw that says one way is better that the other.

 

When you change ECU files you should also be wiping the ECT (electronically controlled transmission) when doing so the tranny has to relearn all the shift points- when you flash the ecu does the transmission shift really weird for the first drive? That’ll be it relearning, if you’ve never wiped the ECT it wouldn’t be a bad idea on your next flash

 

I just put that cooler on my brothers 19, I didn’t realize someone made a bracket till after I made my custom bracket for him, I was pissed lol

 

Fluid in at the top, gravity aids flow

 

I'll trace lines from the thermostat and check when I get a chance but it seems like my pan temps are staying very stable.

i think I might just be overreacting to the TC temp volatility that seems to be the norm

 

Now I had always thought fluid in at bottom, and back to the trans from top to help eliminate any trapped air.

 

What about if you have the inlet and outlet of the cooler angled to the bottom?

 

Now I had always thought fluid in at bottom, and back to the trans from top to help eliminate any trapped air. Also, what are the torque values for the fill and drain on the tranny?

 

Bubbles are only a problem with inlet and outlet at the bottom. Don't have FSM with me for torque values, sorry.

 

same

 

Not worth me switching imho. Thanks 2mchfun.