I have a 2007 Denali with 215,000. Towing my boat in the tow mode, transmission is not shifting, at 55mph @3700rpm. This only happens when the tow switch is on. looking for any advise, thank you
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towing issue
- Thread starter Skibum
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I have a 2007 Denali with 215,000. Towing my boat in the tow mode, transmission is not shifting, at 55mph @3700rpm. This only happens when the tow switch is on. looking for any advise, thank you
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Without the boat, does it shift all the way up and down normally (albeit at higher rpms with each gear)?
My 2007 holds lower gears for longer in tow/haul mode than my 2012 does. How heavy is your boat?I have a 2007 Denali with 215,000. Towing my boat in the tow mode, transmission is not shifting, at 55mph @3700rpm. This only happens when the tow switch is on. looking for any advise, thank you
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yes, it shifts just fine!
I not sure, its a 2003 ski Nautique 210, 20ft with tandem trailer, maybe 3000 to 4500lbs
My guess is that at 55, you're right at the threshold of the next upshift. Try taking it to 60 or 65 and see if that's enough. Like I say, my 2007 Denali holds lower gears for longer than I'd like when in tow/haul mode. And, with a trailer that light you don't really need to use tow/haul mode.
Looking at the specs for that boat, I would guess it is closer to 5500 lbs combined boat and trailer. That still shouldn’t be a major problem for your Denali.
I agree with @Geotrash, maybe try it without tow mode and see if the shift points are more where you want them.
I agree with wsteele.. I bet that boat/trailer combo is over 5000 lbs...
And you are probably right between the gears... You'll have to slow down just
a hair or speed up a few mph and see if it will upshift.
On my 6L80 4th gear revs just a little too much for my liking, but 5th gear
tends to lug just a bit while towing my 9000 lb camper
So I had "thought" about changing to 3.73 Gears so I could use 5th gear,
but with it being AWD, that's too expensive $$$ to justify.
So I just drive about 60-62 in 4th gear. To use 5th I've gotta be about 67-68 mph
And you are probably right between the gears... You'll have to slow down just
a hair or speed up a few mph and see if it will upshift.
On my 6L80 4th gear revs just a little too much for my liking, but 5th gear
tends to lug just a bit while towing my 9000 lb camper
So I had "thought" about changing to 3.73 Gears so I could use 5th gear,
but with it being AWD, that's too expensive $$$ to justify.
So I just drive about 60-62 in 4th gear. To use 5th I've gotta be about 67-68 mph
gooffeyguy
Tom
9000 lb
Try towing in 3rd gear not in Tow/Haul mode and see if you like it better or not.
