Improve Transmission Longevity

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Nap73

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Hey guys what’s up.

I’ve got an 04 Yukon XL SLT with 185k. Had it for a few Months now. My transmission shifts and feels fine. I was wondering if there are steps I can take to keep it that way. I’ve heard about installing a corvette servo,upgraded trans cooler, tuner etc . Does anyone have any input as to what if anything can be done to extend the life of the transmission. I’d appreciate any suggestions.

Thanks
 

SnowDrifter

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Regular maintenance is key

Don't do any of the half ass mods like turning up the pressure valve. You'll shred your valve body

There's a TSB about installing a second magnet in the pan

Upgrade factory cooler. Trucool 40k is what I used. HPT has an install kit that's about as close to plug and play as you can get.

Bypass the factory radiator loop if you can, install a t-stat in the transmission. The radiator loop is just a heater if you're in stop and go or working with the trans. Goal is to keep temps low. I spoke with a few builders, they all told me the lower the better. Mine runs between 110 and 120. Higher than that and I flip on my radiator fans. I don't have an oil thermostat on it but it'll be on my to-do list if/when I need to replace my radiator

Corvette servo - better holding power. While you're in there, look into a pin set. Move to a longer pin if needed, there's a few YT tutorials on how to measure tolerances for the second gear band

Drive with a light foot. The v8 in these trucks has the 4l60 at its limits. Keep the torque off it
 

Doubeleive

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I put a B&M deep pan on mine that holds a extra 2qt's and the trucool 40k. before that mine would be easy 180-205, now it runs 100-135 (winter), summer around 145 so it gave it real nice drop in temps. I also have the filter and fluid changed "annually".
 
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Nap73

Nap73

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Regular maintenance is key

Don't do any of the half ass mods like turning up the pressure valve. You'll shred your valve body

There's a TSB about installing a second magnet in the pan

Upgrade factory cooler. Trucool 40k is what I used. HPT has an install kit that's about as close to plug and play as you can get.

Bypass the factory radiator loop if you can, install a t-stat in the transmission. The radiator loop is just a heater if you're in stop and go or working with the trans. Goal is to keep temps low. I spoke with a few builders, they all told me the lower the better. Mine runs between 110 and 120. Higher than that and I flip on my radiator fans. I don't have an oil thermostat on it but it'll be on my to-do list if/when I need to replace my radiator

Corvette servo - better holding power. While you're in there, look into a pin set. Move to a longer pin if needed, there's a few YT tutorials on how to measure tolerances for the second gear band

Drive with a light foot. The v8 in these trucks has the 4l60 at its limits. Keep the torque off it


I’m not doing any crazy mods. Just inquiring what others have done to help the weak transmission issue.

What would a second magnet do ?

I’ve been looking at upgrading the cooler. Thanks for the make and model. I’ll be adding this very soon.

How would I bypass the radiator loop? Are there any tutorials on this

The corvette servo is something else I’m definitely doing. What is the advantage of the longer pin?

It’s a 3rd car for me and definitely more fun to drive than any of the newer suvs I have. I’d really rather not have to “drive with a light foot” by no means am I looking to beat on it. But I’d like to be able to not have to take it easy. Short of a new trans built to address the weak points what else could I do ?

Anything else that can reasonably be done would be appreciated.

Thanks
 
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Nap73

Nap73

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I put a B&M deep pan on mine that holds a extra 2qt's and the trucool 40k. before that mine would be easy 180-205, now it runs 100-135 (winter), summer around 145 so it gave it real nice drop in temps. I also have the filter and fluid changed "annually".


You think the deeper pan makes a real difference? Or is it the upgraded cooler keeping it that much cooler.

Thanks
 
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Nap73

Nap73

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IMO filter change, flush, and an additional cooler would be the big 3 and the easiest to do.

I have no idea what the other owners have done regarding the trans. So I’m a little hesitant to do this. But I’m definitely going to. You see no downsides to this ?


Thanks
 

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