Transmission Fluid Change

[AE1M]

What it is the opinion about changing transmission fluid in a truck not used in "extreme" conditions?  Daily driver, hauling stuff when needed, etc,,.  Have a 2016 HC just hitting 60K miles.   Having no issues and want to keep it like that.  It would be done on a regular service visit (dont give me crap, I am physically unable to get under the truck and do this).

 

Bob

 

[diyer2]

Change it. Give me a reason not to.

[rav3]

OK, here's my opinion. (keep in mind, others may not agree, but you asked) I do a "drain & fill" every 30k miles, no filter change. I do not crawl under the truck, I suck the old fluid out the fill tube, approx 5 qts & refill with full synthetic Dexron VI, as I have the 6L80 6 speed transmission. I don't know what you have (6 or 8 speed) I believe the 8 speed takes a different fluid. This method is quick & easy, rather than fighting the exhaust pipe that is under the pan. I also did the "transmission thermostat bypass" mod just to keep the temp of the fluid lower. I bought my truck as a used Certified from Chevy dealer with 30k on it. I've actually done this 'drain & fill' at least 2-3 times to make the overall change effect better/more complete. The filters are very porous & do not filter out the small crap, just the big stuff & I have never seen a clogged filter even at 150k. Most small stuff will settle to the bottom of the pain & surface tension will keep most of it there, which is non magnetic. the magnets take care of the steel particles. Just look at a pulled pan. Anyway, that's what I do. 

[KARNUT]

Iv usually half the recommended. You used to be able to go by the smell test. I would either go through the fill tube or drop the line. Seems their doing away with the tube. And now there’s thermostat in the line. So you have to go under. I’ve never done a flush, just drain and fill. Usually repeat a week apart to be more compleat. 

Edited July 6, 2021 by KARNUT

[Grumpy Bear]

14 hours ago, AE1M said:

What it is the opinion about changing transmission fluid in a truck not used in "extreme" conditions?  Daily driver, hauling stuff when needed, etc,,.  Have a 2016 HC just hitting 60K miles.   Having no issues and want to keep it like that.  It would be done on a regular service visit (dont give me crap, I am physically unable to get under the truck and do this).

 

Bob

 

 

IMHO Bob there is no such thing as 'normal' conditions. All service is extreme. Ever since GM put thermostats on transmissions. Did my first drop, filter and fill at 50K and the OEM fluid was done. I've since done the pill flip, done an 8 quart pan with a drain plug and several drop and fills. Every 25 K I do 8 quarts. 

[16LT4]

I'll be doing this on my '17 6 speed today in anticipation of a trip NY-Key Largo next week.  Not going to pull the pan for filter, though; just remove the drain plug in the stock pan, drain out the fluid, and then pour in the ~6 quarts of new Redline D6 with a half bottle of Lubegard Red.  The fluid change is a 10-15 minute ordeal.  The fluid was last changed about 14k miles ago.  I recently "flipped the pill" so even with the short OCI, the fluid has been heated.

 

In my manual on the 6L45, GM lists the ATF replacement at 45k, or as little as 15k miles under "Extreme" conditions; I'm assuming the same holds true for the 6L90.  That transmission runs about 20*F cooler than the 6L90, too.  It is interesting that the manual specifically calls out "stop and go" driving" as extreme.  I'm not familiar with the 8 speed.  So, I agree with the above posters; there's no viable reason not to change the fluid, other than risk of fluid contamination.

Edited July 7, 2021 by 16LT4

[Grumpy Bear]

On 7/6/2021 at 7:52 AM, diyer2 said:

Change it. Give me a reason not to.

 

I can't

 

[Black02Silverado]

Yes change it out. 

 

I do a full ATF fluid exchange out on my new vehicles at 10k miles and switch it over to AMSOIL fluids.  Then at 50k I drop the pan and replace the filter and top off the fluid.  Next 50k I just drain the pan and top off with fresh fluid.

 

I did go a little extra on my 2002.  Got busy and just plain forgot and dropped the pan and fluid change at 100k miles on the fluid.  I did send off a sample and it came back good. 

 

Take care of you transmission like you do the engine and life will be good.

[16LT4]

9 hours ago, 16LT4 said:

I'll be doing this on my '17 6 speed today in anticipation of a trip NY-Key Largo next week.  Not going to pull the pan for filter, though; just remove the drain plug in the stock pan, drain out the fluid, and then pour in the ~6 quarts of new Redline D6 with a half bottle of Lubegard Red.  The fluid change is a 10-15 minute ordeal.  The fluid was last changed about 14k miles ago.  I recently "flipped the pill" so even with the short OCI, the fluid has been heated.

 

In my manual on the 6L45, GM lists the ATF replacement at 45k, or as little as 15k miles under "Extreme" conditions; I'm assuming the same holds true for the 6L90.  That transmission runs about 20*F cooler than the 6L90, too.  It is interesting that the manual specifically calls out "stop and go" driving" as extreme.  I'm not familiar with the 8 speed.  So, I agree with the above posters; there's no viable reason not to change the fluid, other than risk of fluid contamination.

Despite the mileage, the fluid came out darker than expected. I also replaced the drain plug as its gasket was flattened and hardened. It took 5 quarts of Redline D6 and a 10 Oz bottle of Lubegard red; I wouldn’t run a transmission without that.

[AE1M]

Dealer told me they don’t drop pan anymore, they have a machine that takes 1hr to flush.  I like that better.  Had it done.

[Grumpy Bear]

23 minutes ago, AE1M said:

Dealer told me they don’t drop pan anymore, they have a machine that takes 1hr to flush.  I like that better.  Had it done.

 

I found out about a year ago that the filter for six speed in the Terrain requires transmission disassembly to replace. 

 

[AE1M]

28 minutes ago, 16LT4 said:

Despite the mileage, the fluid came out darker than expected. I also replaced the drain plug as its gasket was flattened and hardened. It took 5 quarts of Redline D6 and a 10 Oz bottle of Lubegard red; I wouldn’t run a transmission without that.

You have a drain plug on your tranny?

[16LT4]

1 hour ago, AE1M said:

You have a drain plug on your tranny?

 Yes. Hence my drain and fill taking 45 minutes less than yours, and in the comfort of my driveway.
 

 

Edited July 8, 2021 by 16LT4

[elcamino]

The market for Transmission repair is forecast to reach $259.8 million by 2025.   OE lubes often are equal to the performance quality of the cheapest aftermarket oils. It does mean just because GM installed it its the best lube, it only means its good enough for GM.  Look at all the problems with the ATF on the 8speeds.  

[Grumpy Bear]

11 hours ago, elcamino said:

The market for Transmission repair is forecast to reach $259.8 million by 2025.   OE lubes often are equal to the performance quality of the cheapest aftermarket oils. It doesn't mean just because GM installed it its the best lube, it only means its good enough for GM.  Look at all the problems with the ATF on the 8speeds.  

 

Can I get an "Amen"?