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

[L31MaxExpress]

Hi guys, just got a transmission temperature gauge installed on my '97 Express conversion van to..... monitor my transmission's temperature. (The probe itself is threaded into the pressure test port)

As far as I can tell 210F seems a tad hot although within range, but I do not know for sure, hence my posting. Apologies if this is a silly question.

I took it for a drive after getting the gauge working and took it for a 40 minute drive down the road going about 35-45 in the relatively hilly terrain of the Atlanta outskirts. I did push it a bit up hills just to give it a bit of a stress test, but it looks it only went as high as 210F and no higher. I'd say it spent most of the time in 3rd of 4th. Not towing anything either, just me and another person.

What do y'all think?

Thanks

My guess is your van was built with 3.42s. You are probably spending alot of time in 4th and unlocked converter. Given you have a high top, gear swap would be good. 4.10s minimum and preferably 4.56s. My 97 with a low-top got within 1 mpg running 80-85 mph in 3rd as it did in 4th. Trans ran much cooler when it was able to lock he converter. One might think that higher rpm = worse fuel mileage, but rpm is only part of the equation.

 

[alpinecrick]

Hi guys, just got a transmission temperature gauge installed on my '97 Express conversion van to..... monitor my transmission's temperature. (The probe itself is threaded into the pressure test port)

As far as I can tell 210F seems a tad hot although within range, but I do not know for sure, hence my posting. Apologies if this is a silly question.

I took it for a drive after getting the gauge working and took it for a 40 minute drive down the road going about 35-45 in the relatively hilly terrain of the Atlanta outskirts. I did push it a bit up hills just to give it a bit of a stress test, but it looks it only went as high as 210F and no higher. I'd say it spent most of the time in 3rd of 4th. Not towing anything either, just me and another person.

What do y'all think?

Thanks

That seems pretty high. I would say there is something else going on. What does the engine coolant temp gauge run at normally? The radiators in the vans are smallish in my opinion, and if the engine cooling system is not in tip top shape it seems it can affect trans temps.

I have a 96 (5.0) and 97 (5.7) G1500 cargo vans and their everyday payload is maxed out. Neither one has the external cooler, but of course they have the standard auxiliary cooler/heat exchanger in the radiator.

I borrowed a good infrared temp gun one time and measured trans temps on my pickups and vans. After running the van home on a very hot summer day and leaving the engine idling I measured temps on the outlet and inlet lines of the trans going to and from the auxiliary cooler. The warmest I saw was about 200 on the outlet side, 165-170 on the inlet.

Virtually all trans temp sensors installed in the test port of 4L60E's I have seen reported on the internet run 160-165 degrees. That seems awful cool compared to what I read with the temp gun. If you're seeing 210 from the test port sensor that does seem very warm.

The caveat is, I'd like to know what the optimum, and acceptable temp range--and where it's measured at-- for these trans are supposed to be.

 

[alpinecrick]

I also want to add that if the rad/ac condensor/whatever else might be up in here have never been cleaned of the 25 years of road grime, leaves, bees and butterflies you might want to do that as it will absolutely stop air flow. you will be very suprised how much crap will accumulate up in here.

Al

Glad you mentioned that. I went on a radiator cleaning and fin straightening binge last summer, and some parts of the radiators and condensers were pretty well plugged, especially on the vans. It did make a small difference in indicated engine coolant temps on my dash gauge.

Also, keeping the fluid BRIGHT RED (not red, not dark red, not brown, not black) will contribute to the lifespan of trans as much as the biggest badazz cooler one cares to install. Clean fluid is "hungry" fluid--hungry to absorb heat and hangry to suspend particles in the trans. Dirty fluid is not.

One member last year discovered on his Suburban somebody had disconnected the lines to the auxiliary cooler and was running direct to the external cooler, and his trans temps were getting hot when pulling his boat.

That auxiliary cooler is important.......

 

[zetros]

Hi friends, after a 2 hour round trip to the Georgia Summit Racing warehouse (With ABBA songs on loop for good luck) and some trips to and from the local auto parts store I have installed the Hayden 679 transmission fluid cooler kit in my van (shoutout to my old man for another pair of hands). I decided to bypass the stock system entirely just to cut out the possibility of having coolant mixed with my ATF if any wackiness happens to the main radiator. I also believe in this radiator to be strong and independent.

Here are some pictures of the install:

You must be registered for see images attach

You must be registered for see images attach

While perhaps not the cleanest at the moment, I do intend to clean it up a bit more tomorrow, it works great and no leaks even after the drive. I'll have to look at the trans fluid level, but correct me if I am wrong, but I believe most of the fluid had to have drained back into the pan prior to working on it today.

Now, as far as the temperatures go, to test it I had driven the van in similar conditions tonight with the cooler and a few nights ago without the cooler but with the temperature gauge. It was approximately 10 miles I want to say, with the first 5 being relatively flat roads going 45-55. The second half was a hilly backroad going about the same speed. Both nights were within a few degrees of eachother, with tonight being 74 degrees.

Without the cooler, as I have said, it ran consistently at 210 and even went as high as 220 degrees:

You must be registered for see images attach

However, with the cooler, it now runs at a cold 150 degrees and only got up to 160 degrees in very similar conditions:

You must be registered for see images attach

As you can probably tell, I am a happy man. The transmission still shifts great, and I no longer am against giving the 350 the beans to pass or get up to speed and don't feel the floor above the tranny getting warm as before.

Thanks for the information as always. Y'all are good folks.

 

[zetros]

That seems pretty high. I would say there is something else going on. What does the engine coolant temp gauge run at normally? The radiators in the vans are smallish in my opinion, and if the engine cooling system is not in tip top shape it seems it can affect trans temps.

I have a 96 (5.0) and 97 (5.7) G1500 cargo vans and their everyday payload is maxed out. Neither one has the external cooler, but of course they have the standard auxiliary cooler/heat exchanger in the radiator.

I borrowed a good infrared temp gun one time and measured trans temps on my pickups and vans. After running the van home on a very hot summer day and leaving the engine idling I measured temps on the outlet and inlet lines of the trans going to and from the auxiliary cooler. The warmest I saw was about 200 on the outlet side, 165-170 on the inlet.

Virtually all trans temp sensors installed in the test port of 4L60E's I have seen reported on the internet run 160-165 degrees. That seems awful cool compared to what I read with the temp gun. If you're seeing 210 from the test port sensor that does seem very warm.

The caveat is, I'd like to know what the optimum, and acceptable temp range--and where it's measured at-- for these trans are supposed to be.

The engine coolant temp gauge always runs between the first mark and the 210 degree mark, and sometimes moves up to the 210 degree mark. I think it may be due for a new thermostat when I get the Dexcool flushed out.

 

[zetros]

My guess is your van was built with 3.42s. You are probably spending alot of time in 4th and unlocked converter. Given you have a high top, gear swap would be good. 4.10s minimum and preferably 4.56s. My 97 with a low-top got within 1 mpg running 80-85 mph in 3rd as it did in 4th. Trans ran much cooler when it was able to lock he converter. One might think that higher rpm = worse fuel mileage, but rpm is only part of the equation.

That is entirely possible too. I would like to get 4.10s one way or another, and in limited slip flavor if that is applicable.

Oh, and fuel economy is not a concern regardless. I get 10 MPG no matter what, and I doubt a steeper rear end would change much lol

 

[L31MaxExpress]

Hi friends, after a 2 hour round trip to the Georgia Summit Racing warehouse (With ABBA songs on loop for good luck) and some trips to and from the local auto parts store I have installed the Hayden 679 transmission fluid cooler kit in my van (shoutout to my old man for another pair of hands). I decided to bypass the stock system entirely just to cut out the possibility of having coolant mixed with my ATF if any wackiness happens to the main radiator. I also believe in this radiator to be strong and independent.

Here are some pictures of the install:

You must be registered for see images attach

You must be registered for see images attach

While perhaps not the cleanest at the moment, I do intend to clean it up a bit more tomorrow, it works great and no leaks even after the drive. I'll have to look at the trans fluid level, but correct me if I am wrong, but I believe most of the fluid had to have drained back into the pan prior to working on it today.

Now, as far as the temperatures go, to test it I had driven the van in similar conditions tonight with the cooler and a few nights ago without the cooler but with the temperature gauge. It was approximately 10 miles I want to say, with the first 5 being relatively flat roads going 45-55. The second half was a hilly backroad going about the same speed. Both nights were within a few degrees of eachother, with tonight being 74 degrees.

Without the cooler, as I have said, it ran consistently at 210 and even went as high as 220 degrees:

You must be registered for see images attach

However, with the cooler, it now runs at a cold 150 degrees and only got up to 160 degrees in very similar conditions:

You must be registered for see images attach

As you can probably tell, I am a happy man. The transmission still shifts great, and I no longer am against giving the 350 the beans to pass or get up to speed and don't feel the floor above the tranny getting warm as before.

Thanks for the information as always. Y'all are good folks.

If you ever tow, might rethink that cooler arrangement. Radiator into the auxiliary gives best cooling capacity.

Also swap the fan clutch and fan blade. 11 bladed plastic fan for a 99 Tahoe fits and cools alot better than the cheesy 5 bladed steel fan.

Always got about 11-12 in town and 18-19 on the road in my 97 when it had the 350.

 

[L31MaxExpress]

That is entirely possible too. I would like to get 4.10s one way or another, and in limited slip flavor if that is applicable.

Oh, and fuel economy is not a concern regardless. I get 10 MPG no matter what, and I doubt a steeper rear end would change much lol

4.10 would not be deep enough for me for that van. If you run at 70 currently with a 3.42 it would be turning around 2000 rpm in OD. 3rd would put you about 3K. Unlocked converter in 4th would have you around 2,300 rpm. Jump to 4.56 with lockup actually holding lockup would be 2,600 rpm in 4th and it would jump to 3,600 in 3rd. I had a PWM valve sticking in my 97 for a while and would get a P1870 code if driving in overdrive on the highway for a while. Drove everywhere in 3rd for close to a year. Still netted ~17 mpg on a road trip buzzing the 350 at 3,200 rpm @ 75.

 

[alpinecrick]

Sigh........

 

[thegawd]

I was one who had probably 2 transmissions fail because of coolant infiltrating the internal radiators trans cooler. my rad did not leak and had no bad signs. the coolant didn't have any milky residue or anything and the tranny fluid had no signs of coolant in it. but I gernaded a tranny in 20 000 kms and it failed in multiple ways.

the problem was only found by a fluid anylsis while having the tranny rebuilt a stage 3 HD. since it's been 6-7 years and I do occasionally pull heavy loads for a couple hour trips I can say I have not had a single problem. also the company who suggested this since I couldn't afford a new rad said they do do this all the time without problems and it does not affect their warranty. every race truck has this bypassed is also what he said since this shop is a race shop first. so I almost see that oem rad configuration as an eventually timebomb that's guna eventually go off and I dont trust it. i mean it cost me 2 trannys!

so I personally wont ever trust that internal cooler again.

Al