Burning rubber smell in tow mode

I just bought a used 2021 Tundra 5.7 with 15,000 miles on it. When i tow my 26 foot camper in Tow mode a get a burning rubber smell. If I tow the camper with Tow mode turned OFF the smell goes away. Any thoughts on what it may be.

 

Obviously when in tow mode the improved throttle response and shift pattern is burning up your tires.

 

I stopped and checked the tires, the smell is not coming from them.

 

Probably just the smell of 250f transmission fluid…

 

I'd get a transmission cooler on it if towing a 26' trailer. Genuine Cooling has 10% off using tundra10 code before 12pm 3-27. Just ordered one for my 2020.

 

Good idea, but the truck has a tow package that should include a transmission cooler or something else to compensate for overheating

 

It *should*, but Toyota cheaped out on the transmission coolers a few years before yours. My '07 has a dedicated front mount transmission cooler from the factory, this is what folks are recommending you consider upgrading to.

 

Thanks, good to know. However as I said in my original post: while towing, if I turn off tow mode the smell goes away. I turn it back on and the smell comes back.

 

Are you towing in Tow/haul mode and the transmission in S4? The tow/haul button remaps the throttle response and transmission shift points. I think that's it. Not sur what the rubber smell would be.

 

When I'm in tow mode I leave the transmission in D.

 

Noooooooooooo. Need to put the trans in S4 when towing heavy loads.

 

Staying in S4+TH is also no perceivable difference in gas milage versus staying in D+TH from what I have seen.

Anecdotal story time:

I just made a trip from MN to TX pulling an empty 12x6 enclosed trailer. Interstate most of the way with strong cross wind the whole way, 65-70mph.

Started in D+TH through the first tank. Avg 10.5 mpg.

Second tank was S5+TH,switching as needed to S4 on the grades. Avg 10.4

Third was S4+TH. AVG 10.3

Averaged were hand calculated miles ÷ gallons. Though the computer was only a few tenths higher.

Again anecdotal. More data is needed, but I was shocked to say the least. I would have thought S4 would have sucked down more gas running at 3k plus RPM.

 

I'm seeing the similar results towing my 23" travel trailer. Only noticable difference is trans temps as shown on a Scangauge.

 

Here is a copy of the manual which will have this and a host of other useful information.

https://assets.sia.toyota.com/publi...*MTcxMTU3NzQ4MS4yLjEuMTcxMTU3NzUxNC4yNy4wLjA.

 

I'm in tow/haul/S mode 24/7. Just prefer how it runs and shifts vs. normal mode, which to me feels like everything is being choked off. Plus I can choose gears depending on the driving conditions.

For example in smaller rolling hills with say a speed limit of 45mph and light traffic. The trans will continuously lock/unlock or shift in and out of 5th and 6th.
In tow/haul mode and S5 it will hold that gear through the whole section.