So my first tow with new rig and trans got a little warm.
So here was my situation: Truck:2017 F350 4x4 CCLB 6.7psd 3:55gears truck all stock w/1200mi
Trailer: 34' toybox 14,400lbs
Trans in tow/haul mode, and i just let it do its thing. steady uphill pull running 60-65mph. 80 deg. outside.

guessing entire trip hills varied between 2-4% grade over the 200mi. journey with a short grade of 6% at the end but that's not where it ran warm.

trans temps varied between 218-225 with a brief peak at 235 which scared me

My 2016 6.2 f350 never ran above 215 mostly stayed around 210 but could never pull 5th or 6th gear.

so with the new diesel it pulled 6th gear most of the time. does this cause the extra heat or do i need the dealer to check it??

Thanks ahead for your input.

 

That peak of 235 is high...my temp reads from 215 to low 220's when towing. Not pulling any height's in Louisiana other then bridges!! Same trailer weight but 4.10 gearing...temp outside was in the 80's. Friday I'll pull it again but now our temps are in the 90's and humid as hell!! I'd have the dealer check the truck out to be on the safe side.

 

My opinion on this is that the 6.7L diesel can pull in low RPM's all day long but those low engine RPM's aren't good for the transmission. I base all this on my experience with my 1/2 ton truck so it may not be a good comparison.

Towing in overdrive (5th gear) in my 1/2 ton is going to cause the transmission temperature to go high when I hit a hill/mountain. I need to be in 3rd gear to keep the engine RPM's up, which allows for more fluid to flow through the transmission.

I have yet to tow my toy hauler into the Colorado mountains - that will happen this weekend. If I see the transmission temperatures start to get above 220° F then I'm going to start locking out upper gears.

 

Seems a little high to me.....last summer up in Utah, going west on I-70 out of Green River pulling my Raptor it was 108*F that day, and I don't remember the trans going over 220. Engine oil temp got up around 248, but even that for the conditions was not bad.
But that hill was enough to make the Beast downshift to 4th gear if I remember right......so that could be why my trans temp was lower.

 

When pulling my fiver in the mountains I see 228 all the time. Couple of threads on here about the temps and most seeing the same temps. Don't think I have seen anyone with 235 yet, but could be wrong. What did your oil and coolant get to? My oil runs 244 and coolant 223.

 

Coolant stayed right at 220 +or-
I don't remember oil temps but it didn't seem at all high.

 

Eazmo, I live in SW Colorado and tow an 11k toy hauler. I see trans temps of 235 all the time. I too was wondering if it is bad but the temperature never seems to go above 235 and the fan usually kicks into high gear when I reach this temperature bringing it down to around 228. It never has thrown an alarm yet so I figure it is fine.

 

I had transmission temp get up to 220F going through the mountains in PA towing a 12,500lb 5th wheel. Outside temp was about 85F. I also noticed the transmission gauge displayed a digital readout of the temp when it hit 210F. It displayed the digital readout above the gauge, similar to the DTE readout above the fuel level. Most of the time, the transmission temp was right at 205F.

 

I made a trip through Pa over the weekend and my 6.2l CC was running 202-205 with no trailer

 

We just returned from a weekend run from western NC to northern VA (via I40, I77, I81, and I66) and back (via I66, I81, and I26). Lightly loaded and not towing, our truck's trans temp gently cycled between 194 and 203F as the trans thermostat did its job.

HTH,
Jim / crewzer