Transmission Overheated on my Ford E350 Chassis Shasta

time2roll wrote:

Johnny Dearborn wrote:
I was in second gear going up the Whitney Portal grade. Idling was actually the thing that set it off overheating. Once I stopped moving, it began to overheat and the fluid came pouring out.

What I should have done was keep driving as fast as I could even if it was around the campground. Unfortunately, at Whitney Portal, once you get to the top, there's no place to really go but down. I did the Lee Vining Canyon/Tioga Pass grade twice earlier that week without any problems. There at least there was enough time for the engine to cool down once I got to the top of the grade.

That Whiney Portal is a fairly long and steep climb. I wonder if you were lugging the driveline a bit when in second. If you have a tachometer I think you are looking for 3500 to 4200 rpm when you encounter such a grade. Possibly you would have been better to be in low gear at maybe 3500 rpm and 25 mph when climbing (estimated numbers).

More rpm means more air through the radiator, more air through the auxiliary cooler, more fluid flow, less heat from the torque converter.

Yes as you reached the top the fluid was already about boiling and as soon as you started to idle you had less cooling and the existing heat pushed the fluid over. If you do need to idle maybe keep the rpm up a bit in neutral/park for a couple minutes. (1400/1800 rpm)

I recommend the synthetic fluid for additional heat resistance.

FYI I read the grade steadily increases to 9% for the last 5 miles.

Beware of Nine Mile Canyon road to the south (395) just out of Pearsonville is a solid 9 miles of 10%. And if you detour to Death Valley there are several areas of long 8%/9% grades not to mention summer heat. Stopping immediately at the summit of Whitney Portal is a killer and hard to compare.

Thanks for the insight and tips. I'll look into a synthetic fluid. At least now I know about the issue so I can avoid it in the future. I'm also carrying extra fluid now so if I lose some, I won't be dead in the water.

Johnny Dearborn wrote:
I was in second gear going up the Whitney Portal grade. Idling was actually the thing that set it off overheating. Once I stopped moving, it began to overheat and the fluid came pouring out.

What I should have done was keep driving as fast as I could even if it was around the campground. Unfortunately, at Whitney Portal, once you get to the top, there's no place to really go but down. I did the Lee Vining Canyon/Tioga Pass grade twice earlier that week without any problems. There at least there was enough time for the engine to cool down once I got to the top of the grade.

That Whiney Portal is a fairly long and steep climb. I wonder if you were lugging the driveline a bit when in second. If you have a tachometer I think you are looking for 3500 to 4200 rpm when you encounter such a grade. Possibly you would have been better to be in low gear at maybe 3500 rpm and 25 mph when climbing (estimated numbers).

More rpm means more air through the radiator, more air through the auxiliary cooler, more fluid flow, less heat from the torque converter.

Yes as you reached the top the fluid was already about boiling and as soon as you started to idle you had less cooling and the existing heat pushed the fluid over. If you do need to idle maybe keep the rpm up a bit in neutral/park for a couple minutes. (1400/1800 rpm)

I recommend the synthetic fluid for additional heat resistance.

FYI I read the grade steadily increases to 9% for the last 5 miles.

Beware of Nine Mile Canyon road to the south (395) just out of Pearsonville is a solid 9 miles of 10%. And if you detour to Death Valley there are several areas of long 8%/9% grades not to mention summer heat. Stopping immediately at the summit of Whitney Portal is a killer and hard to compare.

jimx200 wrote:

Olddud wrote:

jimx200 wrote:
We're you on Old Priest Grade? If so, it's a real steep haul up and I have seen cars and trucks off to the side with overheating problems. HD transmission coolers really help. Good luck

He may be referring to Whitney Portal, which is paved to the top, at least it was 45 years ago when I was out there. Darn I'm Old, but not a Priest.

Whitney Portal road is not that steep IMO, but anything is possible to overheat. You are way overdue for a visit! I climbed Mt Whitney back in the late 70's when we had no restrictions or permit needed. Thanks to social media, they trail and surrounding areas for base camping are clogged. Was there last year for some hiking and photography and even midweek there were lots of people.

Yes, I was heading up Whitney Portal. I let the RV sit while I hiked up to Mt. Whitney then dealt with the transmission once I got back. Wasn't going to let the mechanical issues get in the way of a good hike. Managed to get to the top in under five hours. Was quite proud of myself.

time2roll wrote:

If you were in low gear the torque converter was not locked and was building a lot of heat. If you do this again let it idle in neutral 5 or 8 minutes at the top before you shut it off. OK to pull off half way up and let it idle and cool a bit.

I was in second gear going up the Whitney Portal grade. Idling was actually the thing that set it off overheating. Once I stopped moving, it began to overheat and the fluid came pouring out.

What I should have done was keep driving as fast as I could even if it was around the campground. Unfortunately, at Whitney Portal, once you get to the top, there's no place to really go but down. I did the Lee Vining Canyon/Tioga Pass grade twice earlier that week without any problems. There at least there was enough time for the engine to cool down once I got to the top of the grade.

Sonora Pass gets to 26% grades in some places. Not knowing the area a family member suggested I use it to get from Sonora to Bridgeport.
A quick search and comments were made concerning the danger involved with a 30 ft mh.one man said it took 5 years off his life. He was at 10 mph with the pedal floored.
I used the Tioga Pass instead and that was exciting enough.

Olddud wrote:

jimx200 wrote:
We're you on Old Priest Grade? If so, it's a real steep haul up and I have seen cars and trucks off to the side with overheating problems. HD transmission coolers really help. Good luck

He may be referring to Whitney Portal, which is paved to the top, at least it was 45 years ago when I was out there. Darn I'm Old, but not a Priest.

Whitney Portal road is not that steep IMO, but anything is possible to overheat. You are way overdue for a visit! I climbed Mt Whitney back in the late 70's when we had no restrictions or permit needed. Thanks to social media, they trail and surrounding areas for base camping are clogged. Was there last year for some hiking and photography and even midweek there were lots of people.

Found this quote on a older post here on RV.net: "Old Priest Grade is one of the steepest paved roads in Tuolumne County, and some hill-climbing bicyclists believe it’s one of the steepest in the Golden State. Duke York, deputy director for Tuolumne County roads and engineering, said the road is 1.97 miles from bottom to top, with grade steepness up to 18 percent, and the steepest stretch might be closer to 20 percent." per Union-Democrat, a Sonora, CA newspaper.

Also turn off air conditioner to lower heat hitting engine radiator .

I recommend swapping the fluid to Mobil 1 synthetic. Did the engine temperature gauge move? Possible the engine was running at the top of normal due to a worn fan clutch contributing to the transmission heat.

If you were in low gear the torque converter was not locked and was building a lot of heat. If you do this again let it idle in neutral 5 or 8 minutes at the top before you shut it off. OK to pull off half way up and let it idle and cool a bit.

Did u go up it in low gear, or drive?

klutchdust wrote:
A friend has owned a transmission shop for 30 years. He advised me to NEVER flush your transmission, regardless of what the new gimmick suggests. Drop the pan and filter and change the fluid.
He has numerous stories concerning customers who have had a major transmission problem and their first statement is, "i had it flushed" recently.

Flushing causes issues. Particles are released and get into sensitive valving systems
So for the "peace of mind" folks ,do yourself a favor and research before you flush.

And yes, look at the fluid and change when the color changes OR smells burnt.

You have a good friend! Do the scheduled maintenance, and, use the correct fluid. It's that simple folks!

Chum lee