I was towing a 10,000 lbs camper with my 2002 F250 (7.3 PowerStroke) from Washington DC to Townsend TN (we went to the Great Smokey Mountain National Park).

We had been driving for a while (about six hours), and all was fine. June 28, 2010. It was pretty hot outside.

Half-way up the mountain leading to the National Park, the gauge for Trans Temp was dangerously close to yellow. I am pretty sure I was in 2nd gear, going about 25 to 35 mpg behind someone going very slowly. I can't imagine RPMs were over 2000.

I pulled over and rested about 15 minutes with the hood up. When preparing to leave, I latched the hood, but didn't close it all the way.

Starting out, trans temp was normal but quickly and immediately shot up into the yellow area of the gauge.

So I put the transmission in "D" (it had been in "2") AND turned off the Overdrive Off switch (on the end of the gear shift) - this allowed the truck to go into OverDrive if it had wanted to, which it didn't.

As soon as I did this, I watched the needle on the Trans Temp gauge go right back to normal.

First chance I had to check trans fluid on level ground showed it was perfect.

I subsequently drove 9 continuous hours home (after vacation) without any issues.

I've had the truck since it was brand, spanking new and have never had a problem with trans temp. But, I only began towing about 2 years ago.

I am running 38" tires. (I haven't had the speedometer recalibrated, so technically, the vehicle is traveling faster than it thinks - isn't speedometer reading taken from the trans?)

Just wondering what I should do. Have the vehicle checked out? But for what?

Any advice would be appreciated.

 

It probably heated up because of the poor air flow at low speed combined with slippage in the low gears. You did the right thing by pulling over and letting it cool down. It would have been best to leave the engine running while it cooled.

Probably no long term harm done. How does the fluid look and smell?

To prevent it from happening again, you need to add additional transmission cooling capacity. Either an external cooler, or consider upgrading to the 6 liter style trans cooler.

 

Could not hurt to have the tranny checked out, but I think it was just being overworked with a heavy load at slow speed. BTW, ever find yourself in the area again and need help shoot me a PM. I am in North Knoxville, about twenty minutes from where you were at. Would be happy to go out and lend a helping hand to a fellow Ford guy.

 

Note to self: keep engine running next time after stopping. Makes sense now that I think about it.

Mr TennesseeMustangPerf: That's very generous! Thank you. We loved TN. We'll be back.

Here's a pix of our rig taken at Cades Cove campground, TN. It's an AWESOME place.

 

Any time, glad to do it.
Yes, it is very beautiful! Great pic, I think I know right where that was taken... if I am not mistaken, you were just coming out of the Cove and are pointed at the rest stop/information center, right?

By the way, nice looking rig you have there!

 

Did you regear after putting on 38" tires? Running that big of a tire and stock gearing (probably 3.73) will put the most stress on the transmission.

 

How many miles has it been on your truck since a tranny service?

 

That's slot B57 in Cades Cove.

Nope, I didn't regear.

I don't think the tranny's been serviced in the 75k miles I've been driving the vehicle. I may have to check my records - I think the fluid was flushed around 35k miles.

 

Id say go get the fluid and filter changed. Its been a long time and towing a trailer muchless thru the mountains will make it need to be changed sooner.

Cant hurt even if its not 100% due yet if you plan on keeping the truck for a while longer.

 

Quick follow-up: I added an additional cooler. Also changed the fluid and filter.

We'll be towing thru the mountains of Western Maryland in early September, 2010. I better not see the temp rise this time.

 

The speedometer pickup is in the rear differential, not the transmission. You can get it reprogrammed to the correct speed for the larger tires.

Mike

 

Well I am in Frederick. If you travel up I68 toward Cumberland/Frostburg area, there are some long grades.

Best to let that trans gear down as it needs to and keep the rpms up.