Towing

[swathdiver]

That’s climbing up still in tow haul mode correct? If so,does that effect engine braking on the way down since you’re now in the M drive?

Engine braking is disabled while in manual mode. Just shift out of it on the fly if you need to.

Keep in mind that the fluid wears out very quickly the hotter it gets over time. I reckon that your transmission thermostat is still in place, change the fluid before the trip and "flip the pill" as the guys have mentioned. If the fluid is not very old and sees maximum temps on the trip, consider changing it soon afterwards.

 

[Fless]

Don't sweat the transmission temps. You will see 230-240ºF on a few occasions pulling up some big passes (e.g. Togwotee Pass), but don't worry - the fluid is good to 265, according to GM powertrain engineers, with up to 275 okay for short bursts.

I had to look up that pass since I hadn't heard of it. Turns out my Hoe pulled an 18-ft camper over that on my way home from Glacier NP in 2019. Stayed overnight at a FS campground (Falls, I think it was) about 1/3 of the way from the pass to Dubois, WY.

 

[Bigpoppa62]

Engine braking is disabled while in manual mode. Just shift out of it on the fly if you need to.

Keep in mind that the fluid wears out very quickly the hotter it gets over time. I reckon that your transmission thermostat is still in place, change the fluid before the trip and "flip the pill" as the guys have mentioned. If the fluid is not very old and sees maximum temps on the trip, consider changing it soon afterwards.

Thanks, I read that engine braking was disabled in M mode. I’ve never used the M gears and was confused on when and how to use them.

 

[swathdiver]

Thanks, I read that engine braking was disabled in M mode. I’ve never used the M gears and was confused on when and how to use them.

I was pulling a boat and trailer the other day, about 6,000 pounds and climbed up and then down a pretty steep and tall bridge over a waterway, the Cruise Grade Braking did a great job of maintaining speed on the way down and the trailer did not have brakes. Had the cruise set to 45 mph and dropped it to 40 mph as that is the speed limit at the bottom and the truck slowed down going down the grade.

 

[avalonandl]

Trans cooler upgrade is a must. Which gear ratio do you have?

 

[TerryKing]

Hi Everyone,
QUOTE" The 'pill' is a thermostat that prevents the transmission fluid from flowing through the external cooler circuit until it reaches something like 195ºF. That's a problem when towing heavy because by the time the fluid heats up enough to start flowing through the cooler, you're well on your way to a fluid temperature spike."

Can someone please point to How-To??

My 2012 Tahoe 5.3 6L60 seems to always have a smooth increase in transmission temp from start, through normal driving, through uphill tow 5000 lb trailer. I run M5 towing. Max temp 210F but usually about 175F. Normal driving transmission temp usually 100F above outside temp. So I never see a warm up to 195 at all.

So: Do I have a "Pill" at all???

Thanks! Regards, Terry

 

[swathdiver]

Hi Everyone,
QUOTE" The 'pill' is a thermostat that prevents the transmission fluid from flowing through the external cooler circuit until it reaches something like 195ºF. That's a problem when towing heavy because by the time the fluid heats up enough to start flowing through the cooler, you're well on your way to a fluid temperature spike."

Can someone please point to How-To??

My 2012 Tahoe 5.3 6L60 seems to always have a smooth increase in transmission temp from start, through normal driving, through uphill tow 5000 lb trailer. I run M5 towing. Max temp 210F but usually about 175F. Normal driving transmission temp usually 100F above outside temp. So I never see a warm up to 195 at all.

So: Do I have a "Pill" at all???

Thanks! Regards, Terry

Hi Terry, yours does not, that's for the generation afterwards.

Your temps look good to me and normal. Does yours have the external transmission cooler (KNP) and engine oil cooler (KC4)? Does she have 3.08 (GU4) or 3.42 (GU6) gears?

 

[TerryKing]

Does yours have the external transmission cooler (KNP) and engine oil cooler (KC4)? Does she have 3.08 (GU4) or 3.42 (GU6) gears?

THANKS!! Yes I have those 2 cooler codes and GU6 rear..

We just drove/towed about 6000 miles to and from northern Florida and Vermont. Probably the 8th year of that. Before the trip I:

- Dropped trans pan and replaced filter (looked good) at 80,000 (Transmission miles: it was replaced then for probable converter failure: constant hunting. Decided to go for trans also then).. ACDelco GM Original Equipment 10-9244 Dexron VI Full Synthetic fluid. Same for transfer case.
- Changed front and rear differential with Lucas Oil SAE 75W-90 Synthetic
- Changed engine oil / filter Mobil1 5W30 and Mobil 1 M1-113A Extended Performance Oil Filter every 4000-5000 miles
- Usually pump out and replace 5 quarts of transmission fluid through dipstick tube every 5000 miles. Looks/smells good.

When running, once a day right after a long run, I read temperatures with an IR gun. Typical values:
- Wheel bearing center hubs 100 to 140 (Right front always 20 degrees higher)
- Rear differential 165 (I am fussy as lost one in my old Yukon years ago!)
- Trailer bearings hub (all new this year) 85-90

So, yeah I am a little compulsive, but I need to keep this rig running. Tahoe has 240,000 miles total. I will look for / start thread and just how to decide when this engine HAS to be rebuilt / changed. Runs fine now; idle and running oil pressures are 20 and 35 and haven't changed in 150,000 miles.
Any comments / suggestions welcome!

Regards, Terry

 

[swathdiver]

THANKS!! Yes I have those 2 cooler codes and GU6 rear..

We just drove/towed about 6000 miles to and from northern Florida and Vermont. Probably the 8th year of that. Before the trip I:

- Dropped trans pan and replaced filter (looked good) at 80,000 (Transmission miles: it was replaced then for probable converter failure: constant hunting. Decided to go for trans also then).. ACDelco GM Original Equipment 10-9244 Dexron VI Full Synthetic fluid. Same for transfer case.
- Changed front and rear differential with Lucas Oil SAE 75W-90 Synthetic
- Changed engine oil / filter Mobil1 5W30 and Mobil 1 M1-113A Extended Performance Oil Filter every 4000-5000 miles
- Usually pump out and replace 5 quarts of transmission fluid through dipstick tube every 5000 miles. Looks/smells good.

When running, once a day right after a long run, I read temperatures with an IR gun. Typical values:
- Wheel bearing center hubs 100 to 140 (Right front always 20 degrees higher)
- Rear differential 165 (I am fussy as lost one in my old Yukon years ago!)
- Trailer bearings hub (all new this year) 85-90

So, yeah I am a little compulsive, but I need to keep this rig running. Tahoe has 240,000 miles total. I will look for / start thread and just how to decide when this engine HAS to be rebuilt / changed. Runs fine now; idle and running oil pressures are 20 and 35 and haven't changed in 150,000 miles.
Any comments / suggestions welcome!

Regards, Terry

Good, yours is configured for towing 8,200 pounds. As for the oil and filter used, I noticed on mine that that filter lowered my oil pressure 2-3 psi. The oil let my motor rattle more on start up compared with ACDelco oil.

Keep an eye on the hot hub and when you do replace it, make sure the new spindle nut gets torqued to 177 foot pounds. 35mm for stock, 36 mm for Dorman spindle nut. (5177 or 615-095 or 11609826)