ATF for 2002 Tahoe, 4L60E, mild towing

[RDY4WAR]

Originally Posted by Gasbuggy
I thought 3.23 was the lowest numerical gear offered?

FYI, the stock 00-06 1500 gauge cluster will support the trans temp gauge that came standard in the 2500 Suburban. The information is already there from the computer. It's a fairly easy upgrade. I did it on my 02 Yukon XL. In cooler weather, towing 6k with 3 people in the car, the trans didn't get above its normal operating temp.


Thanks for the info.

The code on the sticker in the glove box is GU4 which means 3.08. Doing the math from the RPM, MPH, trans gear, and tire height confirms that as well.

 

[dlundblad]

Good looking truck. Mom and dad had Z71's Tahoes of that vintage. Mom's was that color actually.

 

[SteveSRT8]

Originally Posted by Snagglefoot
I've seen a guy do that with bad results. The rad cooler is still very effective. I would use them both.



Me too. Keep the original cooler setup, it's not known for failure if the coolant is kept clean. Vital for warm up in cold weather.

 

[MolaKule]

Originally Posted by RDY4WAR


I actually like the 3.08 gears. It gets 19.5-20.5 mpg (not while towing) on long drives out of state with the family cruising in overdrive under 2000 rpm. I have no issue leaving it in 3rd gear for towing duty cause like I mentioned, even in 1:1 third gear, I'm still under 2500 rpm cruising down the highway. I keep it in tow mode while towing which increases the line pressure and holds lower gears longer. The converter still locks out in 3rd and 4th gear in tow mode.

I'm not afraid of the miles. The truck is solid. I just want to make sure it stays solid. I plan to keep it until the wheels fall off. It's in excellent condition for being 17 years old.


If that's the gear ratio I would also change the differential fluid every 30k miles with a good 75W110.

 

[RDY4WAR]

Originally Posted by MolaKule
Originally Posted by RDY4WAR


I actually like the 3.08 gears. It gets 19.5-20.5 mpg (not while towing) on long drives out of state with the family cruising in overdrive under 2000 rpm. I have no issue leaving it in 3rd gear for towing duty cause like I mentioned, even in 1:1 third gear, I'm still under 2500 rpm cruising down the highway. I keep it in tow mode while towing which increases the line pressure and holds lower gears longer. The converter still locks out in 3rd and 4th gear in tow mode.

I'm not afraid of the miles. The truck is solid. I just want to make sure it stays solid. I plan to keep it until the wheels fall off. It's in excellent condition for being 17 years old.


If that's the gear ratio I would also change the differential fluid every 30k miles with a good 75W110.


I have a stock of Amsoil Severe Gear 75w-140 that I use in the track car. Would that work?

 

[Rat407]

I tow a 20' enclosed trailer with my 2002 Silverado, 5.3 same transmission as you. I have been running AMSOIL's ATL transmission fluid in it since the ATL came out and before that AMSOIL's ATF. My transmission temperatures hang around 170° F on the interstate. Trailer weights around 5k lbs. I keep it in 3rd to keep it from hunting gears and I have a 3:73 rear gear. I also have 186k on the original power train. No issues. The main thing is to keep an eye on your transmission temp. I'm lucky and the factory setup keeps things cool. This is even when towing in the heat of summer here in eastern NC which can get up to high 90's low 100's at times.

I did install a 2002 Denali gauge cluster back when I got the truck so that I would have a factory transmission temperature gauge. Easy to install and it is plug and play since the temp probe is already there, you just need the cluster with a temperature gauge.

I also just run AMSOIL's Severe gear 75w-90 and change it out every 100k. No issues with it either per UOA.

 

[4WD]

If you want to go back to early Dex versions … compare specs on Mobil 1 ATF …
For the money that pan costs … a remote filter and $10 drain plug kit is less money and well spent
(toss nylon washer for copper) … then flip the pan volume and filter in 20 minutes …

 

[Chris142]

Originally Posted by RDY4WAR
Originally Posted by Chris142
Bummer about the 3.08 gears. That trans will be struggling for sure. I recommend dex6 in it. It definitely needs a better cooler. Keep in mind that most if not all of these trucks pump the fluid from the bottom of the cooler and out the top! So when you put on a cooler check the flow direction.


Noted. Thanks.

I actually like the 3.08 gears. It gets 19.5-20.5 mpg (not while towing) on long drives out of state with the family cruising in overdrive under 2000 rpm. I have no issue leaving it in 3rd gear for towing duty cause like I mentioned, even in 1:1 third gear, I'm still under 2500 rpm cruising down the highway. I keep it in tow mode while towing which increases the line pressure and holds lower gears longer. The converter still locks out in 3rd and 4th gear in tow mode.

I'm not afraid of the miles. The truck is solid. I just want to make sure it stays solid. I plan to keep it until the wheels fall off. It's in excellent condition for being 17 years old.

Ours has 3.42 gears. It looks exactly like yours with the exception of a few parking lot dings my wife put on it. Ours gets about 17mph on the hwy.

 

[clinebarger]

GU5 is the RPO for 3.23:1 gears, GU4 is for 3.08:1.

I've never seen a build sheet or a SPID list either of these ratios on a GMT800 Tahoe/Yukon, Do you mind posting a picture of the SPID sticker??

 

[mattwithcats]

So your options are...

Tranny oil cooler, comes as a kit.

Deeper transmission pan. You need to look and see what pan is on, because GM was killing the Firebird, and a lot of shallow pans were left over, and they used them wherever they could...
Aftermarket pans are available even deeper, remember to use the deep tranny filter...

7 Gauge cluster... original was 6.

Delvac ATF is at Summit Racing cheap...

 

[nascarnation]

Originally Posted by mattwithcats
For a transmission that uses Dexron III, I suggest a TES 295 fluid...

https://www.allisontransmission.com/parts-service/approved-fluids/on-highway-fluids



Wisdom
75000 miles in NYC Sanitation >>> forever in consumer use.

 

[umungus1122]

Originally Posted by Chris142
Originally Posted by RDY4WAR
Originally Posted by Chris142
Bummer about the 3.08 gears. That trans will be struggling for sure. I recommend dex6 in it. It definitely needs a better cooler. Keep in mind that most if not all of these trucks pump the fluid from the bottom of the cooler and out the top! So when you put on a cooler check the flow direction.


Noted. Thanks.

I actually like the 3.08 gears. It gets 19.5-20.5 mpg (not while towing) on long drives out of state with the family cruising in overdrive under 2000 rpm. I have no issue leaving it in 3rd gear for towing duty cause like I mentioned, even in 1:1 third gear, I'm still under 2500 rpm cruising down the highway. I keep it in tow mode while towing which increases the line pressure and holds lower gears longer. The converter still locks out in 3rd and 4th gear in tow mode.

I'm not afraid of the miles. The truck is solid. I just want to make sure it stays solid. I plan to keep it until the wheels fall off. It's in excellent condition for being 17 years old.

Ours has 3.42 gears. It looks exactly like yours with the exception of a few parking lot dings my wife put on it. Ours gets about 17mph on the hwy.
Wow, 17mpg on the highway? What is your avg. speed? I get 22-25mpg on the highway at 55-65 with 3.08 gears and tbi 305 with a weight of around 5000 including load.