4L60e running at 200-210F at operating temp.

[stutaeng]

My brother had his 700R4 fail a little after his radiator cooler failed and mixed water in his tranmission. After the rebuild he bypassed it. I can understand why a guy would bypass it.

It does happen, but pretty rare on these trucks as far as I know.

I run the radiator coolers on my trucks.

There are some vehicle that this radiator cooler failure is super common to fail. The second generation 4Runners come to mind (strawberry milkshake I think they call it?) but pretty sure there are others as well.

If I recall from basic thermodynamics theory, the heat exchange rate is MUCH better from a liquid than from air, so that explains a lot. Heck, that explains why our engines aren't air cooled! LOL

 

[R422b]

ok heres a damn good question,

how are you ever guna tell if your rad starts leaking coolant into your transmission?

When it doesn't go in to gear anymore. [emoji1787]

Talking about GMT400s using Tapatalk
"Is this before or after you fired the parts cannon at it?" - Supercharged111

 

[R422b]

My brother had his 700R4 fail a little after his radiator cooler failed and mixed water in his tranmission. After the rebuild he bypassed it. I can understand why a guy would bypass it.

It does happen, but pretty rare on these trucks as far as I know.

I run the radiator coolers on my trucks.

There are some vehicle that this radiator cooler failure is super common to fail. The second generation 4Runners come to mind (strawberry milkshake I think they call it?) but pretty sure there are others as well.

If I recall from basic thermodynamics theory, the heat exchange rate is MUCH better from a liquid than from air, so that explains a lot. Heck, that explains why our engines aren't air cooled! LOL

I bought a transmission from bowtie overdrives in California and they don't give a warranty unless there is a radiator heat exchanger in the system.

Talking about GMT400s using Tapatalk
"Is this before or after you fired the parts cannon at it?" - Supercharged111

 

[df2x4]

My brother had his 700R4 fail a little after his radiator cooler failed and mixed water in his tranmission. After the rebuild he bypassed it. I can understand why a guy would bypass it.

It does happen, but pretty rare on these trucks as far as I know.

I run the radiator coolers on my trucks.

X2. I'm team radiator cooler but I understand why some people don't trust them. Both of my '97s run the rad cooler and an external cooler, and I upgraded the external on my red truck to a TruCool M7B.

The only thing I would suggest is that if you're considering bypassing the radiator cooler, I would put the biggest nastiest standalone external cooler you can fit on there. Like a TruCool 40K (LPD4739).

https://www.amazon.com/Tru-Cool-LPD4739-4739-Pressure-Transmission/dp/B00803CTDA

 

[thegawd]

I had just replaced the tranny and it only had 20000 kms on it. brand new fluid. and no signs of coolant at all in the fluid. it was found only by a fluid anylsis.

so how do you tell if you coolant is mixing with your fluid?

you guys are making me wish I had a transmission temp gauge. this is not available with a scanner is it?

 

[stutaeng]

Just get one that plugs into the pressure test port. That's what the OP did...

Pick one up from local auto parts store or Amazon.

 

[zetros]

X2. I'm team radiator cooler but I understand why some people don't trust them. Both of my '97s run the rad cooler and an external cooler, and I upgraded the external on my red truck to a TruCool M7B.

The only thing I would suggest is that if you're considering bypassing the radiator cooler, I would put the biggest nastiest standalone external cooler you can fit on there. Like a TruCool 40K (LPD4739).

https://www.amazon.com/Tru-Cool-LPD4739-4739-Pressure-Transmission/dp/B00803CTDA

This is what I did. The cooler I have is technically overkill for my application but since I was bypassing the stock one I went one size up. The Hayden 679's radiator is 11x11 inches, which is pretty beefy imo

 

[zetros]

I had just replaced the tranny and it only had 20000 kms on it. brand new fluid. and no signs of coolant at all in the fluid. it was found only by a fluid anylsis.

so how do you tell if you coolant is mixing with your fluid?

you guys are making me wish I had a transmission temp gauge. this is not available with a scanner is it?

I wish it was available through and OBDII scanner, but my bluetooth one that hooks up to my phone didn't have any option close to it. That being said, doing a clean install of a gauge like I did took just a few hours of my time.

 

[R422b]

That being said, doing a clean install of a gauge like I did took just a few hours of my time.

Mine took me 2 days but I wanted the backlight to dim with the radio lights so I had to pull the gauge cluster and radio and sort out the wiring which on my O2 took me a while to figure out.
Everything is in wire loom and every connection is soldered and sealed with shrink tubing.
Talking about GMT400s using Tapatalk
"Is this before or after you fired the parts cannon at it?" - Supercharged111

 

[L31MaxExpress]

This is what I did. The cooler I have is technically overkill for my application but since I was bypassing the stock one I went one size up. The Hayden 679's radiator is 11x11 inches, which is pretty beefy imo

Its actually far from being big enough for your application. Will work on a lightly loaded van, but work it hard uphill with 5K behind it and you will smoke that 4L60E from burned fluid in no time. Will probably overheat it just running the van up a mountain as well.

My Express van had a trucool 40K on it but I found it overkill with the radiator cooler in place. Backed down to a M7B after the radiator cooler. The M7B is 2x the thickness of the 679 with 2x the cooling fin surface area and a better design than the tube and fin.