[DurmaxPowderHound]

Just for fun. Feel free to include any roads that travel along steep grades. Here is my list.

Stevens Pass, WA
Snoqualmie Pass, WA
Manastash Ridge, WA
Deadman Pass (Cabbage Hill), OR
Teton Pass, WY
Targhee Pass, WY/MT
Homestake Pass, MT
Lookout Pass, ID/MT
Fourth of July Pass, ID
Sea to Sky Highway, BC
Cayoosh Pass (Duffey Lake Road), BC
Rogers Pass, BC
Kicking Horse Pass, BC/AB

All of the above passes have been with my Forest River R Pod, which with a typical load is about 3000 +/- pounds. Many of them have been in wintertime with snow and ice on the roadways. I was typically able to hold 60-65 MPH on most of the Interstate Highway passes, save of course for adverse conditions and any curvy parts that required me to go slower. The passes that really worked my truck were a tossup between Teton Pass and Cayoosh Pass since both are very steep (10% + grades) and curvy. Thank goodness for the exhaust brake going down those stretches!

The picture below as taken at the summit of Teton.

 

[bigoilbob]

Just for fun. Feel free to include any roads that travel along steep grades. Here is my list.

Stevens Pass, WA
Snoqualmie Pass, WA
Manastash Ridge, WA
Deadman Pass (Cabbage Hill), OR
Teton Pass, WY
Targhee Pass, WY/MT
Homestake Pass, MT
Lookout Pass, ID/MT
Fourth of July Pass, ID
Sea to Sky Highway, BC
Cayoosh Pass (Duffey Lake Road), BC
Rogers Pass, BC
Kicking Horse Pass, BC/AB

All of the above passes have been with my Forest River R Pod, which with a typical load is about 3000 +/- pounds. Many of them have been in wintertime with snow and ice on the roadways. I was typically able to hold 60-65 MPH on most of the Interstate Highway passes, save of course for adverse conditions and any curvy parts that required me to go slower. The passes that really worked my truck were a tossup between Teton Pass and Cayoosh Pass since both are very steep (10% + grades) and curvy. Thank goodness for the exhaust brake going down those stretches!

The picture below as taken at the summit of Teton.

View attachment 8139

We've been on ~1/3 of these roads, towing an Escape 5.0 TA. Mostly in winter/spring. We go 60 or less, always. Locked hubs in high a couple of times and REALLY slowed down when roads got glazed. Max trans temp ~220F. And we also thank goodness for that exhaust brake system. Emphasis on "system". It works so seamlessly. Our EGR failed at Sioux St. Marie and we were willing to wait on one and border hop for 4 days, to avoid driving without the jake brake. Once you use it to tow heavy, you never go back....

 

[DurmaxPowderHound]

We've been on ~1/3 of these roads, towing an Escape 5.0 TA. Mostly in winter/spring. We go 60 or less, always. Locked hubs in high a couple of times and REALLY slowed down when roads got glazed. Max trans temp ~220F. And we also thank goodness for that exhaust brake system. Emphasis on "system". It works so seamlessly. Our EGR failed at Sioux St. Marie and we were willing to wait on one and border hop for 4 days, to avoid driving without the jake brake. Once you use it to tow heavy, you never go back....

I'm curious where you have the transmission temperature readout. It's not a standard gauge on my truck, which is a 2016.

 

[terryjm1]

4300 feet elevation climb in 16 miles pulling a 6500 pound articulating boom. Max trans temp 219 at 45 mph. Alamogordo, NM to Cloundcroft, NM.

 

[bigoilbob]

I'm curious where you have the transmission temperature readout. It's not a standard gauge on my truck, which is a 2016.

On my 2018 CCLB Z71, it's on my driver information scroll down. Let me think. I get:

Average fuel economy
Instant fuel economy
Distance left until dry
Speed
Percentage of oil life left
Percentage of fuel filter life left
Tire pressure (read out for all 4)
Oil pressure
DEF level (ok, or 30% or less left)
Transmission temperature

Not necessarily in that order, and I might be forgetting something. I can also toggle between metric and US, for Canada. Then, I get those strange terra newtons per square furlong units for oil pressure and leagues/cubic kilometer for mileage. I over toggle on trips, especially towing. Need to work on that......

 

[bigoilbob]

4300 feet elevation climb in 16 miles pulling a 6500 pound articulating boom. Max trans temp 219 at 45 mph. Alamogordo, NM to Cloundcroft, NM.

Per others in this forum, I think you're good. Crowd wisdom seems to suggest that anything under 240-250F is ok. Any new IMHO's or corrections to mine, about yours, folks....?

 

[terryjm1]

4300 feet elevation climb in 16 miles pulling a 6500 pound articulating boom. Max trans temp 219 at 45 mph. Alamogordo, NM to Cloundcroft, NM.

I should add outdoor temp was about 90 degrees and fell to about 70 by the time I got to the top of the mountain.

 

[kramerica5000]

I just pulled my Black Series HQ12 camper (about 4800lbs) from Moab (4500ft) to Warner Lake Campground in the La Sals (9400ft). Tranny hit 240º. The exhaust brake was a lifesaver on the way down. Just had to tap my brakes for the corners.

 

[bigoilbob]

I just pulled my Black Series HQ12 camper (about 4800lbs) from Moab (4500ft) to Warner Lake Campground in the La Sals (9400ft). Tranny hit 240º. The exhaust brake was a lifesaver on the way down. Just had to tap my brakes for the corners.

View attachment 8211

240 trans temp is the highest I've seen in the forum. You like the exhaust brake on the way down (me too), but were you in trailer tow mode on the way up? We've dropped down to 40-45 m/h for over 20 minutes on STEEP hills with a GCVW of over 10,500#, AC on, in summer, heavy foot feed (or equivalent with cruise on), and never got above 217-220F on our 2018 Z71 CCLB. What year is your truck and are there any differences in trans cooling over the years?

Separately to all, after over a year on the forum Spacey Casey finally looked right and found a "like" button. If I commented on your post but didn't "like" it, it wasn't because I didn't like it....

 

[kramerica5000]

240 trans temp is the highest I've seen in the forum. You like the exhaust brake on the way down (me too), but were you in trailer tow mode on the way up? We've dropped down to 40-45 m/h for over 20 minutes on STEEP hills with a GCVW of over 10,500#, AC on, in summer, heavy foot feed (or equivalent with cruise on), and never got above 217-220F on our 2018 Z71 CCLB. What year is your truck and are there any differences in trans cooling over the years?

Separately to all, after over a year on the forum Spacey Casey finally looked right and found a "like" button. If I commented on your post but didn't "like" it, it wasn't because I didn't like it....

It's a stock 2017. I've read of a few people hitting similar temps, even 250. Apparently up to 250 is fine and at 270 you'll get reduced power & a warning to pull over and let it cool down. AFAIK nothing has changed with the cooling.

https://www.coloradofans.com/forums...l-transmission-running-temps.html#post4960041

I always use tow/haul mode when towing. My speeds were pretty low and there were a lot of hairpin corners to accelerate out of and the whole climb probably took the better part of an hour. For most of if I was in the 220-230 range.

 

[norcaltoy]

Pulled a 6k flat bed with a vehicle on it over the Siskiyou Summit at the CA/OR border. Held 55mph up the hi and exhaust brake held me at same speed on the way down. Peaks at 4300 elevation. Saw 235° trans temp on the way up the hill. I have seen 240 trans temp at a different time.

 

[bigoilbob]

Pulled a 6k flat bed with a vehicle on it over the Siskiyou Summit at the CA/OR border. Held 55mph up the hi and exhaust brake held me at same speed on the way down. Peaks at 4300 elevation. Saw 235° trans temp on the way up the hill. I have seen 240 trans temp at a different time.

Thanks norcaltoy. You are the second reporter of higher trans temps that I've seen here. Do you remember the range of ambient temps going up? And I'll ask you the same ? I asked kramerica5000. Were you in trailer towing mode going UP the hill?

And for the both of you, do you think you were locked up?*

Asking because I'm going LONG. 20 years or more. If I can use driving practices that are not too radical to stay below 220, I would like to do so. This, even though other posters say that the temps you experienced are not trans life reducing.

Thx again....

*This begs a more general question to the forum. I have been thru my manual and watched the forum for this, but in trailer towing mode, does the trans lock up in whatever gear it finds itself? I'm sure it unlocks as a last ditch effort to keep going in low, but other than that, which gears lock up when, when we switch the truck to trailer tow mode? Not trying to duck research - I really have looked...

 

[norcaltoy]

Thanks norcaltoy. You are the second reporter of higher trans temps that I've seen here. Do you remember the range of ambient temps going up? And I'll ask you the same ? I asked kramerica5000. Were you in trailer towing mode going UP the hill?

And for the both of you, do you think you were locked up?*

Asking because I'm going LONG. 20 years or more. If I can use driving practices that are not too radical to stay below 220, I would like to do so. This, even though other posters say that the temps you experienced are not trans life reducing.

Thx again....

While towing the 6k trailer I was in tow haul mode. Ambient temp would have been low 70s

The day that I saw 240 I actually wasn't towing. I was out for a drive on some gravel backroads cruising 15-25mph, ambient temp would have been in the 80s. The drive was in the mountains and the converter was likely not able to lock for any significant amount of time resulting in the high temps. From memory I think I switched between tow haul being on and off to see if it made any difference in trans temps. I probably should have put it in manual mode and selected a gear myself

 

[bigoilbob]

norcaltoy

"I probably should have put it in manual mode and selected a gear myself."

Maybe, maybe not Sounds to me like your driving was just fine. My 220 was from slowly backing a heavy trailer up a tortuous hill in low 4wd. If I had not gotten to where I wanted to be in time it would have kept going up.

Thanks for writing back.

 

[norcaltoy]

norcaltoy

"I probably should have put it in manual mode and selected a gear myself."

Maybe, maybe not Sounds to me like your driving was just fine. My 220 was from slowly backing a heavy trailer up a tortuous hill in low 4wd. If I had not gotten to where I wanted to be in time it would have kept going up.

Thanks for writing back.

I think I in both our cases, a lack of airflow over the radiator/trans cooler was probably a contributing factor. On other vehicles I've owned, adding a small external trans cooler with a fan on it made a significant difference in trans temps. I haven't seen too much info from anyone on the forums who has added an extra cooler but it shouldbt be too difficult to find a spot

 

[bigoilbob]

I think I in both our cases, a lack of airflow over the radiator/trans cooler was probably a contributing factor. On other vehicles I've owned, adding a small external trans cooler with a fan on it made a significant difference in trans temps. I haven't seen too much info from anyone on the forums who has added an extra cooler but it shouldbt be too difficult to find a spot

No expert,and feel free to school me, but i thought that our trans coolers only exchanged heat between radiator fluid and trans fluid. After getting to running temp, my engine temp has never moved enough to see - almost eerie. I think my solution will be to watch trans temp when I think I should, and back off when it gets to my arbitrarily - with no data to back me up - 220 degF.

 

[PowderMonkey]

Lizard Head Pass CO, my gutless fj couldn’t hardly make that pass happen, it was a good rig but nothing like the DMAX!!

 

[bigoilbob]

PowderMonkey, off thread, but how did you get your Casita up so high? When we bought ours we got the lift kit, but this is large. Looks like a Casita body on a different frame. It's up so high, does it sway? As you know, they tow well. We towed ours with either our '95 K2500, 350 X Cab short bed with 3.73 gears and trailer tow pack, our our 2004 208 HP Volvo XC90. Heavy hitch weight, but the XC90 had that auto level suspension and pumped up on the road.

 

[PowderMonkey]

PowderMonkey, off thread, but how did you get your Casita up so high? When we bought ours we got the lift kit, but this is large. Looks like a Casita body on a different frame. It's up so high, does it sway? As you know, they tow well. We towed ours with either our '95 K2500, 350 X Cab short bed with 3.73 gears and trailer tow pack, our our 2004 208 HP Volvo XC90. Heavy hitch weight, but the XC90 had that auto level suspension and pumped up on the road.

PowderMonkey, off thread, but how did you get your Casita up so high? When we bought ours we got the lift kit, but this is large. Looks like a Casita body on a different frame. It's up so high, does it sway? As you know, they tow well. We towed ours with either our '95 K2500, 350 X Cab short bed with 3.73 gears and trailer tow pack, our our 2004 208 HP Volvo XC90. Heavy hitch weight, but the XC90 had that auto level suspension and pumped up on the road.

No man, no frame alterations or anything like that. There’s a company out of Texas called (Jim’s orbital machine shop) they have a lift and a shock kit for the Casita. I also put 31” BFGs on it. It sits about 6” than normal, it’s great because I can take it through the worst terrain it handles it just fine. Also when I’m towing I don’t have to ever look back.

 

[PowderMonkey]

All you guys out there going up and down these passes are any of you getting a high pitched whine from your turbos when your working the truck and getting it hot?