I recently heard about how prone the torque converters are know to fail on most the full size gm suv and trucks. I’m curious to know if there is anything you can do to prolong the life of the transmission? We have 85000kms on our 2017 yukon, I’m sure we are due for a transmission oil and filter change at the very least
Torque converter issues
- Thread starter chartersj
- Start date
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other than changing the fluid and filter very often then you would need to upgrade some internal parts before it fails
@Doubeleive completely agree. I do every 40 to 50k on my 2017 8 speed. Don't even really have to drop the pan. Just have it flushed and keep the fluid clean. I talked to an old timer who's done transmissions for YEARS and he said the filter change really isn't necessary as long as the fluid is kept clean. It's more of a safeguard for big shit that fails and the will hopefully save the small stuff. I've had the filter changed twice and I'm due for another service at 130k. Gonna just flush it and move one.
I do mine annually so less than 20k miles, in fact I do all fluids annually except the rear diff & transfer case those i do every 2-3 years
What transmission do you have (6 or 8 speed)?
Fluid and filter every 24-36k for daily drivers; 12-18k for heavy duty, towing, working beyond the scope of private party ownership patterns.
Failing to change the filters in these six and/or eight speed units can result in increased contamination, them getting partially restricted resulting in inconsistent oil pickup and slippage at WOT.
The six speeds (6L45, 50, 80, 90) are also prone to pump wear on the working surfaces as well as wear in the pressure regulator valve. Keeping up with fluid changes mitigates the associated risks and helps prolong the life of these units.
The eight speeds (8L45/90) have a TSB for TC shudder and harsh 1-2 upshift, primarily due to use of wrong fluid used. Per the link, flushing the trans with mobile 1 synthetic (or presumably any quality full synthetic fluid) helps.
The solenoids (or techm) in between types of transmissions are also very sensitive to contamination, moreso than earlier units like the 4L60e.
Address pattern failures by installing updated parts and performing requisite procedures on overhaul.
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Ours is a 5.3 6 speed. Is this a diy job or better off letting a shop do the flush and filter?
You can do it yourself if you’re reasonably handy though its best to have a helper with you. There’s instructions out on the net for DYI trans flushes. Since you have less than 100k on the vehicle, most shops should be willing to do the flush (many wont once milage tops 100k).
If you are also planning to replace the TECHM then I’d take it to a shop or GM dealer so they can do the flushing as well as acquire, install it and flash/run the adaptive learn on the new TECHM so it controls the trans properly.
Never heard of changing the techm. What exactly is that for?
The GM six speeds all use a transmission control module known as a “TECHM” and it’s responsible for commanding and controlling the trans. It consists of a bunch of solenoids and pressure switches as well as an internal mode switch together in all-in-one unit that informs the pcm which range has been selected on the shifter (Park, Reverse, Neutral, Drive, etc) and then controls shifting, line pressure and other vital functions while the vehicle is running and moving.
Here’s a quick overview.
So the techm needs to be replaced every once in a while or the new ones are different then the stock ones? Sorry for all the questions and appreciate all the insight !!
