7.3L Power Stroke Engine and DrivetrainDiscussion of the 7.3L Power Stroke diesel engine and drivetrain in the 1999-Up Super Duty trucks and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 7.3L Power Stroke engine.
I pulled my 11,500 lb toy hauler up a 2 mile long steep windy dirt road at an average speed of 15 mph to get to a campground. When I arrived at the campground, I back up a steep hill to get the toyhauler into the campsite. While I was backing up, a bunch of transmission fluid came out of the transmission. I turned off the engine and waited awhile to let it cool, then I replaced 1 1/2 gallons of transmission fluid to fill it up again. A few minutes later, the ranger came and said that there was a forest fire approaching the campground, and everyone had to evacuate immediately. So I pulled the toyhauler back down the windy 2 mile dirt road, and to another campground about 15 miles away. The transmission worked perfectly all the way to the next campground.
Does this mean that my transmission is ruined, or is it fine since it worked perfectly on the 15 mile trip to the next campground?
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2001 F350 XLT 4X4, shift on the fly, 38 gal fuel tank, running boards, sliding rear window, black, crew cab, long bed, 4.10, automatic transmission, 11,500 gvwr, 20,000 gcwr, 7500 gvw, dual rear wheels, 7.3l turbo diesel, completely stock, 114,00 miles when purchased, now has 125,000 miles, repairs so far: starter, batteries, cps.
2005 Nomad Rampage toyhauler made by Skyline. 11,500lb gvwr.
Well, it overheated due to both slow speed climb under load AND backing up under load. You really need to get a trans temp gauge to be safe when towing. Your truck *should* have the trans cooler in the radiator as well as the air cooler for the fluid, so it's hard to tell how hot you actually got. If you don't have the cooler in the radiator, you prolly got very hot.
FYI : When the trans overheats, DO NOT shut it off. Let it idle, or even better, put it in park or neutral and high idle it. That'll cool the fluid much faster than sutting the truck off.
Best bet is to change your fluid and hope for the best. It's hard to tell for sure when damage is done. You may well just have fried the fluid and the trans is fine.
Best of luck!
Note : Plan on budgeting for the 6.0 trans cooler (mine will be goig in anytime). People swear by it. it's over 3 times larger than the air cooler our trucks came with and helps with the temps a ton.
Uphill reverse with a heavy load on an already hot 4R100 can be a killer. Its best to let it cool down after a long slow pull before attempting it. I had my 02 do that a couple times on me (puke fluid) and wished I would have had a decent tranny temp gauge. I never had any problems with it for the year I owned it after that though. But as already suggested, a good cooler and temp guage is the best way to protect your trans.
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2004 F-350 Lariat, Supercab 4X4 FX4, DRW
Dark Toreador Red/Silver, 6.0L, Torqueshift Auto, ESOF, 4.10 LS, Camper Package, Dual Alternators. Build Date 6-8-04, Eng 5-28-04, Lance 9.5 Ft Camper.
Thank you for your valuable comments. I'll order the 6.0 transmission cooler and a set of gauges right away, and change the transmission fluid, and hopefully, I was lucky and didn't damage it too much.
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2001 F350 XLT 4X4, shift on the fly, 38 gal fuel tank, running boards, sliding rear window, black, crew cab, long bed, 4.10, automatic transmission, 11,500 gvwr, 20,000 gcwr, 7500 gvw, dual rear wheels, 7.3l turbo diesel, completely stock, 114,00 miles when purchased, now has 125,000 miles, repairs so far: starter, batteries, cps.
2005 Nomad Rampage toyhauler made by Skyline. 11,500lb gvwr.
An alternative that would obviate all of the above reply's would have been for you to put your transmission in 4x4 "" LOW RANGE"" while backing up.....
I SERIOUSLY doubt , if you would have encountered your problem....[provided you have a 4x4]
An alternative that would obviate all of the above reply's would have been for you to put your transmission in 4x4 "" LOW RANGE"" while backing up.....
I SERIOUSLY doubt , if you would have encountered your problem....[provided you have a 4x4]
Yes, I do have 4X4. Are you saying that the transmission will not overheat while backing if it is in 4X4 low range? If that is true, then that is certainly a valuable thing to know. Thanks for that information.
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2001 F350 XLT 4X4, shift on the fly, 38 gal fuel tank, running boards, sliding rear window, black, crew cab, long bed, 4.10, automatic transmission, 11,500 gvwr, 20,000 gcwr, 7500 gvw, dual rear wheels, 7.3l turbo diesel, completely stock, 114,00 miles when purchased, now has 125,000 miles, repairs so far: starter, batteries, cps.
2005 Nomad Rampage toyhauler made by Skyline. 11,500lb gvwr.
Yes, 4WD low that will help the backup worries as it locks your torque converter. However, you should still let it cool after long rages under load before you attempt more. The gauge is the only way to know when you're near your limits.
Buy a trans temp and egt gauge at least, and a boost too if you can. I just got done about 2 hours ago with the install of my 6.0 cooler. Not the easiest install due to room issues, but not horrible. My Excursion also has a blocker beam underneath that was quite fun to remove...
Anyway, with that 31 row cooler, most say 30-50 degrees cooler in your trans. I asked a lot about adding the Oil to Water (OTW) cooler, which is the one that goes through the radiator. All the trucks have Oil to Air (OTA) coolers. During normal flatland towing in high heat (90s) 195 was pretty common. Then on grades she would go up to prolly 210-215 and stay there until back to flatland. It's truly pathetic how small the stock OTA cooler is in these trucks - 9 rows vs 31. Sheesh.
Anyway, MANY said that the 6.0 cooler alone is enough when coupled with the OEM fan (even w/o the OTA cooler). I'll be pulling through the mountains this summer for 2 weeks, so we shall see.
I never had problems with mine until I got into stop and go traffic in a grade with my camper on the truck, and once on a 10 mph crawl to the top of Mt Washington unloaded (prolly a 25% grade). Both times I stopped when she hit 230 degrees and let it idle. Here's hoping I don't have to worry about those numbers ever again.
I pull a 15k 5ver fulltime. Whenever I'm in slow (25mph less) traffic for any length of time, OR, if going uphill slowly, dirt or asphalt, OR, backing into a site, I ALWAYS go to 4 wheel low, unlocked hubs.
I have never overheated with my stock setup.
But then what do I know, only got 209,000 on my orig stock 4R100.
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'01 PSD F350/SC Lariat 6x6 Hercules
"Save the Planet. Its the only one with Chocolate"
I pull a 15k 5ver fulltime. Whenever I'm in slow (25mph less) traffic for any length of time, OR, if going uphill slowly, dirt or asphalt, OR, backing into a site, I ALWAYS go to 4 wheel low, unlocked hubs.
I have never overheated with my stock setup.
But then what do I know, only got 209,000 on my orig stock 4R100.
I thought that the hubs locked automatically with 4 on the fly. Do you have to unlock them?
I actually had the truck in 4 wheel low while I was climbing the windy dirt road at 15 mph for 2 miles, but at the campground, the road was paved; so I put it back into 2 wheel drive just before I backed up, and then the fluid came out. I guess that was one of my mistakes. I should have let it cool, then left it in 4 wheel drive low.
Is it alright to be in 4 wheel drive low on pavement?
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2001 F350 XLT 4X4, shift on the fly, 38 gal fuel tank, running boards, sliding rear window, black, crew cab, long bed, 4.10, automatic transmission, 11,500 gvwr, 20,000 gcwr, 7500 gvw, dual rear wheels, 7.3l turbo diesel, completely stock, 114,00 miles when purchased, now has 125,000 miles, repairs so far: starter, batteries, cps.
2005 Nomad Rampage toyhauler made by Skyline. 11,500lb gvwr.
Driving in 4x4 with the front hubs engaged, puts a lot of stress on the drive line because of binding, the wheels want to turn at different speeds, but the transfer case keeps the front wheels turning at a consistent offset compared to the rear wheels. However, the driveline can probably deal with this better than the transmission, especially in reverse where the gear ratio on the 4R100 is actually higher than in first gear. (in soft ground, you will notice it take higher engine rpm to start moving in reverse gear than in first gear if you are on the level)
Read the posts on 2 wheel drive low, it is easy to do if you have installed manual hubs, like I have, but also simple with ESOF, you just disconnect the electrical connector to the Pulse Valve Hublock vacuum solenoid on the right fenderwell, near the vacuum pump, BEFORE you switch from 2WD into 4 x 4.
4 x 4 Low does not automatically lock the torque convertor, otherwise you would not be able to idle when out of neutral or park. The low range, means the torque convertor does not have to work nearly as hard to make enough torque to move the vehicle. If the torque convertor does not have to make as much torque, it also is not making as much HEAT!
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2000 Excursion Limited born 11/99 4x4 Toreador Red ext./gray int. 7.3PSD, 3.73LS, Skidplates, Pwr/Htd TeleMirrors, 6CDchanger, HtdBuckets, LT265/75R16E Bridgestone Dueler A/T Revo, Ford Wraparound deflector, PSDV8 badging, RoofMarkerLights, Tekonsha Sentinel brake cntrlr, PCM=AXD0, Edge Evolution II, WalkerBigTruck Muffler, RS9000, RS5410, Performance Friction 2 piece rotors/pads, Sylvania SilverStars, Landyot Gen III, Air Lift rear air bag system, Amsoil from MAXoil.com in diffs/trans/transfer 251k miles.
Driving in 4x4 with the front hubs engaged, puts a lot of stress on the drive line because of binding, the wheels want to turn at different speeds, but the transfer case keeps the front wheels turning at a consistent offset compared to the rear wheels. However, the driveline can probably deal with this better than the transmission, especially in reverse where the gear ratio on the 4R100 is actually higher than in first gear. (in soft ground, you will notice it take higher engine rpm to start moving in reverse gear than in first gear if you are on the level)
Read the posts on 2 wheel drive low, it is easy to do if you have installed manual hubs, like I have, but also simple with ESOF, you just disconnect the electrical connector to the Pulse Valve Hublock vacuum solenoid on the right fenderwell, near the vacuum pump, BEFORE you switch from 2WD into 4 x 4.
4 x 4 Low does not automatically lock the torque convertor, otherwise you would not be able to idle when out of neutral or park. The low range, means the torque convertor does not have to work nearly as hard to make enough torque to move the vehicle. If the torque convertor does not have to make as much torque, it also is not making as much HEAT!
Thank you, ExcursionPSD, for your valuable information. Now the entire situation is finally making sense to me. I drove two miles at 15 mph up a steep, windy dirt road in 4 wheel drive low. But when I got to the paved area where the campgrounds were, I forgot to change to 2 wheel drive, and I drove around on the pavement in 4 wheel drive low for awhile checking out the campsites. That must have been when the transmission overheated, since I was binding the wheels and putting tremendous stress on the transmission. Then when I starting backing up a steep hill into the campsite, I remembered that I still had it in 4 wheel drive low, and changed to 2 wheel drive, but the transmission was already overheated, and backing made it worse, and the fluid came out.
Thank you, ExcursionPSD, for your excellent explanation that finally tells exactly what happened.
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2001 F350 XLT 4X4, shift on the fly, 38 gal fuel tank, running boards, sliding rear window, black, crew cab, long bed, 4.10, automatic transmission, 11,500 gvwr, 20,000 gcwr, 7500 gvw, dual rear wheels, 7.3l turbo diesel, completely stock, 114,00 miles when purchased, now has 125,000 miles, repairs so far: starter, batteries, cps.
2005 Nomad Rampage toyhauler made by Skyline. 11,500lb gvwr.
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