Should I install a transmission cooler?

[Hardwarz]

I'm hard on transmissions. The tahoe is the first light truck that I've owned in YEARS. I have a 99 Tahoe, 4 door 4x4 with the 350 Vortec. I actually baby the engine because of fuel prices.

I tow on occasions. Almost always under 1000 lbs and only once a month or less.

Do I have to worry about putting in a transmission cooler? Also, what's the best way to change the transmission fluid. I'm use to having drain plugs, this one, I don't want to drop the pan if I can help it.

Also, what transmission do I have? If I have to drop the pan, I'm just going to go to Summit Racing and pick up a pan with a drain plug and heat fins.

Hardwarz

 

[Mike97]

I installed a transmission cooler on my 97 Tahoe. I rarely tow anything, but I have had two transmissions die in other Chevy trucks I've owned. I figure better safe than sorry. Since the biggest killer of automatic transmissions is heat, it won't hurt to install a cooler. And it only took me a couple hours to do it.

If you want to change the transmission fluid, you will have to drop the pan. The filter is in the pan, and you need to change that when changing the fluid. But simply draining out what is in the pan only changes 20 to 30 percent of the fluid. Most of it is still in the transmission and torque converter. To completely change the fluid, you need to flush out the old fluid while adding new. This is best performed by a shop with the equipment to do it.

Your transmission is probably a 4L60E. If you are lucky it is a 4L80E, but I don't think they put those in any Tahoe's. This website describes Chevy transmissions and how to identify yours. http://www.nastyz28.com/chevy-transmission-identification.php

 

[Rollin Thunder]

according to the link, that over drive was an the 4l80e and not on the 4l60e, so if you have over drive you most likely have the 4l80e but im not sure, i might have read the link wrong.

 

[Mike97]

No, the 4L60E is also an overdrive transmission. Basically an electronically controlled 700R4 with overdrive. The 4L80E is an electronic version of the TH400 with overdrive. Chevy pul the 4L60E in all their 1/2 ton trucks and some of their 3/4 ton trucks. The 4L80E was installed in 3/4 and 1 ton trucks.

 

[Rollin Thunder]

i mis read the link th, i didn't think they put the 80 on half ton.

 

[Hardwarz]

No, the 4L60E is also an overdrive transmission. Basically an electronically controlled 700R4 with overdrive. The 4L80E is an electronic version of the TH400 with overdrive. Chevy pul the 4L60E in all their 1/2 ton trucks and some of their 3/4 ton trucks. The 4L80E was installed in 3/4 and 1 ton trucks.

so, if the 4L60E is basically a electronically controlled 700R4, I can get a 700R4 pan for the Tahoe, correct? (Or are there several bolt patterns for pans I have to worry about?)

Hardwarz

 

[Hardwarz]

I installed a transmission cooler on my 97 Tahoe. I rarely tow anything, but I have had two transmissions die in other Chevy trucks I've owned. I figure better safe than sorry. Since the biggest killer of automatic transmissions is heat, it won't hurt to install a cooler. And it only took me a couple hours to do it.

If you want to change the transmission fluid, you will have to drop the pan. The filter is in the pan, and you need to change that when changing the fluid. But simply draining out what is in the pan only changes 20 to 30 percent of the fluid. Most of it is still in the transmission and torque converter. To completely change the fluid, you need to flush out the old fluid while adding new. This is best performed by a shop with the equipment to do it.

Your transmission is probably a 4L60E. If you are lucky it is a 4L80E, but I don't think they put those in any Tahoe's. This website describes Chevy transmissions and how to identify yours. http://www.nastyz28.com/chevy-transmission-identification.php

On my old Intrepid, I added a transmission cooler. I put it inline with the stock transmission cooler/heater. Did you do the same thing during your install?

Also, on the 'trepid, we usually disconnected the hose that goes to the cooler, start the car, and with the brake on, put it in drive. The pump would put out all the old transmission oil. Once that was done, we'd put in the new fluid. Would this work with the Tahoe?

Also, would an external filter system be useful on the Tahoe?

Hardwarz

 

[Mike97]

On my old Intrepid, I added a transmission cooler. I put it inline with the stock transmission cooler/heater. Did you do the same thing during your install?

Also, on the 'trepid, we usually disconnected the hose that goes to the cooler, start the car, and with the brake on, put it in drive. The pump would put out all the old transmission oil. Once that was done, we'd put in the new fluid. Would this work with the Tahoe?

Also, would an external filter system be useful on the Tahoe?

Hardwarz

No, I replaced the stock transmission cooler with a bigger unit. But you can install it in line with the stocker if you want. I just didn't have the room for both coolers.

I wouldn't recommend pumping out the fluid unless you can figure out a way to replenish it as it's being pumped out. That is exactly what some shops do when flushing transmissions, but they add fluid at the same rate that it is being pumped out. I wouldn't run it low on fluid because it is not good to run the pump dry.

I don't know anything about using an external filter system for an automatic transmission. But you would still want to replace the one in the pan. The fluid has to go through it before going to the pump. If it gets too plugged, your pump will be starved of fluid and burn out. You can't run without it unless you fabricate some kind of pickup tube to replace it, because without it the fluid will not be picked up and the pump will not be able to pump any oil. There is really no easy way around dropping the pan, but a drain plug will definitely help. I installed one in my tranny pan on my old pickup. Make filter changes a lot less messy.

 

[2000 Z71 Tahoe]

i dont see why a transmission cooler wouldnt be a bad idea. i have been thinking about installing one myself.

as far as draining it you do have to drop the pan. but the best thing to do would be to take it to your chevy dealer and have them flush the transmission.

Aaron

 

[Hardwarz]

I'm a Mobile 1 fan, so a dealer fluid exchange will be pricy. Plus, a lot of the local shops around town use multi-manufacturer ATF fluid. I have found out that there are big differences between the multi-manufacturer transmission fluid and the specific fluids for each car manufacturer. I'm not willing to use the generic ones.

Hardwarz

 

[Mike97]

so, if the 4L60E is basically a electronically controlled 700R4, I can get a 700R4 pan for the Tahoe, correct? (Or are there several bolt patterns for pans I have to worry about?)

Hardwarz

Sorry, I missed that question. I'm not sure if it would fit. Why would you want to do that? The 700R4 does not have a drain plug either. You can drill your pan and put an aftermarket drain plug in it. I did that on an older pickup I owned. I just checked it for leaks whenever I was under there for engine oil changes.

 

[Mike97]

I'm a Mobile 1 fan, so a dealer fluid exchange will be pricy. Plus, a lot of the local shops around town use multi-manufacturer ATF fluid. I have found out that there are big differences between the multi-manufacturer transmission fluid and the specific fluids for each car manufacturer. I'm not willing to use the generic ones.

Hardwarz

In the shop I used to work, we had some customers that would bring in their own oil for oil changes. We would use their oil, and charge them less for the oil change. If you have a shop you trust, bring in what ever kind of fluid/oil you want them to use. If you don't trust that the shop will actually use it, then you need to find another shop. You should even get a break on the price of the service.

 

[jwpotts0413]

definitely get a tranny cooler!!! it is the cheapest insurance you can buy

but! be sure you route the coolant lines away from heat and anything that can rub through them. i had one added when i got my tranny rebuilt and the coolant lines were routed improperly. this caused them to wear through and all the coolant leaked out. subsequently my tranny burned up 3rd and 4th gear. luckily they fixed it under warranty.

also, you can get an aftermarket tranny oil pan with a built-in magnetic drain plug from ebay or summit racing. my good friend owns a tranny shop so i never saw the need to invest in one. i will wrench on my ride any time but will gladly let someone else do it when the cost is less then the pain in my ass!