Dumb mistake when towing. Sierra

sierra75 · October 10, 2016

I have a new Sierra with about 800 miles on it.

Had to tow my boat late this weekend, and flat out forgot to put in Tow / Haul mode.

Got out of vehicle and it smelled of hot brakes. Towed about 45 miles.

As I didn't put in tow mode, I don't know what Transmission temp was, but all other gauge readings were fine.

I obviously, won't make this boneheaded error again (and never have on any other vehicle).

My main concern is what got hot and could I have damaged the tranny, axle, etc.?

It wouldn't be so bad if a person didn't know better!!!

redwngr · October 10, 2016

Something else is going on to cause the smell, other than not putting it in tow/haul.

Any chance there is something burning off hat exhaust, rather than a brake smell?

Perhaps overspray from under coat, or an oil leak?

Diver6 · October 10, 2016

You wouldn't have hurt anything, just the new truck smell burning off, the tranny might have gotten a little warmer then if it was in tow/haul mode but that's all it affects, just different shift points it does nothing to the brakes or cooling. Don't know if you have grade braking or not but it might affect that as well I haven't figured that out totally yet on mine. I wouldn't worry you didn't go far. There is a tranny temp gauge in your DIC but you have to turn on the setting in your settings.

newdude · October 10, 2016

I guess I'd be most "concerned" about the brakes (pulsation, fade, etc.). Engine, trans, axles, etc. should be okay. Per GM on tow/haul:

In general, tow/haul mode maintains lower gears longer and increases shift pressures. It is designed to be most effective when the vehicle and trailer combined weight is at least 75% of the vehicle's Gross Combined Weight Rating (GCWR). Operation of tow/haul in a lightly loaded or non-loaded vehicle will not cause damage

45 miles? Should be fine. How heavy was the boat? If the trans got really hot, there would have been a warning message on the DIC as well.

Diver6 · October 10, 2016

Sorry posting problems, I'm new!

MikeNH · October 10, 2016

Tow/haul won't do much for the brakes. It sounds like the boat trailer brakes weren't working (assuming they have any).

NoProblem · October 10, 2016

If you're going to wreck the tranny, best to do it now while it will be replaced for free.

Donstar · October 10, 2016

How heavy was the trailer? My guess you would have the same smells if you used tow/haul mode. Take it back to your dealership to have your concerns answered. You should not be having strange smells at 800 miles. When I had trailers i often forgot to use tow/haul mode. (I was usually reminded by frequent shifting on hills)

LongrangeLauber · October 10, 2016

I had strange smells for the first 2k miles, I think it was just stuff cooking off the exhaust and block, if he smelled brakes it's probably cause he had to use the truck brakes more because he either didn't have trailer brakes or they weren't working properly or he didn't have a controller to have them work properly lol

To answer your question, you didn't ruin anything not using tow haul mode

CRApex · October 10, 2016

Any chance one of your trailer brakes is grabbing a bit too much?

sierra75 · October 10, 2016

The smell came from the truck itself. Boat and Trailer are probably 6700 lbs combined. Boat is 5200 on its own. Again, no warning and engine temp, oil pressure, etc, were all good. Smelled like a hot brake. I've noticed I'm not the only one posting something like this. My guess is it was the brakes and that they are just new.

cbrsilv15 · October 10, 2016

Tow haul button won't do anything for the brakes. It just makes your shifts a little firmer and winds out the gears longer. Youre good.

dave07 · October 10, 2016

Tow Haul WILL help your brakes. When in tow/haul mode the engine will downshift more aggressively and "engine brake" when going down a grade to help save your actual brakes.

StinkyCheese · October 10, 2016

If you lock out gears or manually downshift when towing you don't have really need tow haul. Dad and grandfather never really used it much when we used to tow our travel trailers. I use tow haul more in traffic empty than I do towing but I do light load towing. If you smell something then it's definitely not from not using tow haul.

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Donstar · October 10, 2016

It could be your brakes if your truck is doing more than its share of the stopping power on a 6700 lb. trailer. Any trailer over 2000 lbs should have properly functioning brakes. However, get the smell checked out by your dealer for peace of mind. It is not normal to have a burning brake smell in a properly functioning vehicle and trailer combo.