1999 f 250

Yosty

Member
Hi All
I own 2011 3410E Bighorn fifth wheel unit GVW 14500 DRY 11398 I weighed my truck and trailer with the trailer loaded except for food clothes and the Misses and weighed 20640 I am estimating a GCW of 21000 when all said and done. My truck is a 7.3 with the 3.73 rear and the 4R100 Trans. I use a Edge Evoluion CTS Power level 1 I had my truck weighed at 7500. Here's my problem I tow the trailer with no problem & stop with no problems my trans temp is fetween 175 7 179 TOWING ON THE OPEN RD. I dip very little when I hook up which I think I can fix with air bags. When I have to stop and go traffic my trans temp goes up to 185-189 my concern is my trans I had the trans remanufactured and up graded a year ago and added a extra cooler coil. the GCW for the truck is 20000 so I am 1000 over approxitmately. Is there any body out there with trans problem with the 4R100 and towing a little more than recommended? Thanks in advance for any help
 

MCTalley

Well-known member
When you say you added an extra cooler coil, is that just another small trans cooler inline with the stock trans cooler? The conventional wisdom for 7.3s with the 4R100 is to replace the stock cooler with one from a 6.0 Ford. Much larger and more efficient. Plus, it apparently bolts in pretty easily. We started out with an F350 dually 7.3 and had our tranny custom rebuilt. The rebuilder always replaced the stock cooler with the 6.0 cooler as part of his package. I would look into that.
 

beck-mark

Member
I just got rid of my 2001 because of transmission issues and the fact the I was right at max on GVW but over by about 1500 on the pin weight, not to mention firewood, propane tank, and wood blocks and boards for leveling. I would guess you are in the neighborhood of being overweight by close to 2k on your payload. I had to rebuild the transmission 2 times and that was before I upgraded camper to be where I was at so yes transmission problems but with being under gvw by a good 5k to 7k. And yes I had upgraded my transmission cooler before lost the first transmission and it was no easy task. the 6.0 cooler does fit in the same spot but to get it out and put new one in takes removing most of the front end of the vehicle.
 
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BBslider001

Active Member
I wouldn't worry about those temps at all. That is normal for these trucks. If you saw that going down the road, I might be concerned, but yes, it's normal. Just drive it and be happy! I wouldn't waste the money on a 6.0 cooler. You won't see too much difference from running what you have now.
 

Shortest Straw

Caught In A Mosh
I had my trans rebuilt about 2 years ago by a guy who builds race transmissions. It is a night and day difference over the stock one. We all know that heat can kill a transmission but the heat that you are experiencing does not worry me a bit. Some of the slow climbs here in the mountains brings my temps up around 220 on occasion. Much of that has to do with slow pulls and not being able to go fast enough to lock the torque converter up which generates a lot of heat. I do find on hot days that the heat from the pavement in stop and go traffic will raise the trans temp sometimes by 20 degrees. I also installed a mag hightec 7 quart larger transmission pan. It takes longer for the temps to rise and they also decrease quicker when it does get hot.
 

whp4262

Well-known member
Yosty, I would agree with BBslider001 and Ghettomedic your tranny temps are pretty normal and not something I would be concerned about.


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