3rd gen Transmission Cooler Upgrade

Not sure but hotter fluid is less viscous therefore less friction and maybe better mpg? Also could potentially reduce sludge buildup with less viscous fluid?

 

To be on the safe side, add another cooler.

 

This is a cheap and easy upgrade. Adding it doesn't affect anything but the warranty for this system if you are still under warranty. Long hills will build heat no matter what. My system with the cooler still gets up to 230F in the pan but it take a longer. It cools down a lot faster once the converter locks, as well.

 

Toyota has the trans thermostat to open in the 190 to 192 degree range, so I don't think that 230 degree up hill is excessive. I read that the idiot light doesn't come on until 302 degrees. Now that is excessive heat. I have read over 200 without towing anything or the thermo pinned open. Just normal driving.

 

I have decided to add a second cooler. I am going with the 28,000 GVW tru cool model. I am going to tow my TT up Wolfcreek Pass (11,000 ft) near Durango CO, in a couple of weeks and just don't want to take a chance. I found out that aftermarket add ons won't effect the warranty unless they caused the failure.

 

I've got a weird experience here, and I'm hoping somebody might have some insight or could point out something obvious I missed (don't think I did though).
Basically, I'm seeing higher temps after installing the secondary cooler & changing fluid. Details below.

After looking around at options, I ended up just going with the same cooler and fan that the OP used. Installed it just fine, with the fan as a puller, but NOT wired up yet. I did a fluid change to Valvoline Max Life at the same time, going through 4 drain and refill cycles.

• I installed the cooler in-line after the stock one, inlet on top, outlet on bottom.
• Confirmed it's flowing correctly based on warmer inlet line vs outlet line.
• Had the thermostat pinned throughout the process, but it's un-pinned now (and always ran it un-pinned previously).
• Have confirmed fluid level is good twice since the install.
• On my daily commute (~40 miles one-way, 90%+ highway) my pan temp now tends to equalize right around 200 after say 35 of those miles, whereas it would be more like 194-195 territory before.

Obviously, I still have the fan to try out, but regardless, it doesn't make sense that temps went up.
Air in the lines somewhere? Wouldn't the pump eliminate that issue?
I can't imagine the Max Life runs hotter than WS, right?

 

Good point on the fan, and I might try that out of curiosity, BUT while that may be affecting the cooler's efficiency, it absolutely doesn't explain higher temps than before.
And if settled at 200, the thermostat should be fully open already, but the temps aren't coming down from there like I'd expect.

 

Yeah even w a fan not hooked up, it should still see the stock cooling temps. Doesn't quite compute w me either. Out of curiosity, why did you switch oils?

 

Price/availability.
Multiple experts have confirmed it's fully compatible, despite what Toyota may say to get people to buy their own WS.

 

This is strange. I wouldn't suspect the fluid is running hotter and even if it was the thermostat should compensate.
The fan shouldn't be making a difference since it's really only providing more cooling area even if it doesn't have optimal flow. Actually the only time I ever use my fan is on long hills when I'm going slow pulling a trailer or when I'm in 4lo for extended periods.

Is the cooler too close to or touching the radiator/ac condenser? That could potentially cause heat buildup.

Maybe thermostat malfunction? Depress the the thermostat plunger a few times and make sure its seated correctly. Are you using an inline filter? Maybe it's not flowing properly?

 

I'm definitely switching to another fluid when I hit 60k

 

I just ordered a new magnafine inline filter. I've had the plastic wix filter for about 20k miles now. I'll cut it open and post up some pics of what I find.

 

Hoses aren't kinked / nothing restricting flow? Curious indeed.

 

Right, those are the same reasons I installed the fan. Didn't expect to ever need it under normal conditions.

Plenty of spacing from the radiator & condenser, no filter. I'll double check on the thermo plunger again, but highly doubt that's it...

 

Not that I can see. If nothing changes, I may pull the new lines and cooler to run some air through and verify.

 

Bummer man. Hope you get it sorted!

 

Confirmed no blockages in the new portion of the system.
I decided to put the factory hose back in and bypass the new cooler for a couple days to help narrow down the cause.

 

Keep us posted!

 

Just ordered a Tru Cool 4490 to hopefully fix my Temp issue. I had a warning light and the truck shut off on a trail in 4Lo on a relatively cool day (65f).

Picked up an OBD scanner and Torque Pro & see my daily driving temps are about 195-205 for the pan & Converter. At one point the converter hit 230 I'm 4lo going up a small incline.

I want to pin the thermostat open before I install the new cooler too see the difference, but any downside to leaving it open the whole time?

Also any other reason you guys can think of that she's running so hot? I never see 175 or less

 

195 is pretty normal as that is right around where the thermostat opens. I have upgraded my cooler as well, but would love to find a solution to drop the thermostat opening temp to around 175.