How many miles did you get out of your original Transmission?

[petethepug]

When you take care of your stuff, it pays you back.

2001 Yukon 355K miles and still going.

 

[ktpinnacle]

When you take care of your stuff, it pays you back.

Truth. I think that the transmission cooling with the trailing package I added when I ordered the rig helped, especially driving through the desert. Minimal trailering and I've babied it for the last 8 years or so. No summer desert runs. Same engine as well, for the same reasons.

 

[swathdiver]

99 Yukon 150k og trans no fuid changes
07 Tahoe 187k 1 fluid change
15 Yukon 6 SPD, HMD, 6L-80 93k TBD. Kinda sad to hear how fragile the new trans are as the older ones have provided me with years of good service despite not being on top of preventive maintenance.

It's not the transmission, it's the thermostat they put on the transmission that keeps it too hot. That and the torque converter's skin is too thin. When it gets hot and flexes, the clutch material goes through the transmission wrecking the pump at minimum.

 

[Marky Dissod]

Truth. The transmission cooling with the trailing package I added when I ordered the rig helped ...

Fixed it for you.

It's not the transmission, it's the thermostat they put on the transmission that keeps it too hot.

Even if Dexron6 is well superior to Dexron3, they'll both still perform better and last longer @ 212F
than @ 230F.

That and the torque converter's skin is too thin.
When it gets hot and flexes, the clutch material goes through the transmission wrecking the pump at minimum.

Is a 6L90E torque converter a feasible maintenance upgrade here, or is the aftermarket a better bang for the buck?

 

[NickTransmissions]

Is a 6L90E torque converter a feasible maintenance upgrade here, or is the aftermarket a better bang for the buck?

Depends on who/what you have access to but most competent converter builders will build a much better JMBX (gm code for the 6L80 converter) for $120-150. Add a bunch for a billet cover.

Every transmission type that I have ever worked on runs optimally and lives the longest when temps are kept between 150-190, all other things like keeping up with service intervals, held equal. Dex6 will handle heat better than 3 to a point but heat always "wins" in the end.

For my part, I got nearly 200k out of my 03 Tahoe's original 4L60E before the rear gear train decided to start eating itself on a trip back home from Cali 5 years ago...

 

[the 18th letter]

It's not the transmission, it's the thermostat they put on the transmission that keeps it too hot. That and the torque converter's skin is too thin. When it gets hot and flexes, the clutch material goes through the transmission wrecking the pump at minimum.

I've read as much.

 

[swathdiver]

Is a 6L90E torque converter a feasible maintenance upgrade here, or is the aftermarket a better bang for the buck?

Well, I don't hear about them in having problems in the same way of the JMBX's clutch. They are about 15 pounds heavier and use 6 lugs instead of 3 to bolt to the flex plate.

 

[donjetman]

187k miles on my 2007 6L80 so far.
Changed the torque converter as preventative mx at 130k miles while I was doing the engine rear main seal 4+ yrs ago.
Installed a Precision# P4646 (gopnh.com) converter - $218. Its stronger and for a truck 6L90.
I dump and fill the 6 qts that will come out of the pan every 25k miles and change the filter too every 50k.
I don't tow or hotrod it. I drive conservatively.
Its still going strong.

 

[johns2008]

i got 306000 on my tranny 2008 xl. just need to pinch off two A/C lines to the rear so i can charge up the system , can i cap them in the engine compartment?

 

[bobsburban]

Mine made it 272,000 before eating itself for lunch. Installed a Jasper; we shall see.