i have a 2000 f250 sd 7.3 and put a new built hd for towing 4r100 tranny with billet converter triple disc clutch in at 186000 and it now has 194000 my problem is its overheating .

when i first put it in i used mobil1 syth atf but mixed it up accidentily with the mobil1 syth mercon v compatible stuff i bought 18 quarts and put 14 in and the dip stick said it was full and i checked it hot an cold and after running it down the highway for a bit , dont know how much of each one i put in .

when new it shifted fine and the temp gauge never moved the lowest number is 140 and until june it never saw 140. in june i tried to pull a friends 12000 pound trailer and within 40 miles the temp was over 240 and it wasnt shifting at all just felt like one gear and was slipping i pulled over and shut it off . after a cool down i was able to limp home with the trailer watching the gauge and kept it under 200 . after that it was fine to drive shifted normal and all but the temp goes up to 170 and stays there , now the trans seems to shift ok 1-3 but in over drive it kicks in and out of converter lock up from 45-65 mph with a light pedal i can keep it from doing this .

new problem it now heats up to 200 just driving normal so i changed the trany fluid [thats when i found the mix up in fluids ] to just normal mercon iii and ran it 10-15 miles and then changed it again ,adding a 2nd air to oil cooler ,a larger pan +3 and eliminating the cooler in the radiator and changed the cooler by pass valve which was bad . it flows 48 oz of fluid in 15 seconds,ford spec is 32oz in 15 seconds all the line pressures are above factory specs and it still overheats, pulling a 17000 trailer it took 7 miles to get to 240 it shifted fine till 200 and then it was like one gear .

theres no metal or clutch material in the fluid and when i changed it the first time it didnt smell burnt and was still red , a little dark , and almost nothing on the magnet ,no leaks. could the tourque converter have gone bad from being 4 qts low , it has no codes and the od light is not flashing whats happining .

i stopped driving it a month ago and miss my truck

 

no one else has had this problem i guess

 

3 days and no one has had this problem and there are how many superdutys on the road ?

 

i am not sure because i have an excursion but are the f350's rated to pull 17000?

 

17,000 lbs if not a miss print would be a bit much to pull.

I'd take it back to the rebuilder, a friend had to take his rig back 3 times before they finally got it right. Needless to say....I'd stay away from backyard mechanics.

 

I think everyone's staying away from this one because you haven't gone back to whoever rebuilt it.

There's something funky with it, and that's it.

I don't think mixing the ATF's caused the problems, but it's not going to help you if you want to get it warranteed.

When you say "cooler bypass valve" is that a thermostat?

The first time you pulled that 12K trailer, did it overheat at highway speeds?

Sounds like the thermostat stayed closed when you were pulling that big honkin' trailer, overheated the tranny, and fried the TC clutch. Since it can't lockup the clutch anymore, the temp will stay a lot higher than before, especially if you're in 3rd or 4th gear.

And, it almost sounds like a bearing is going, otherwise, where's all that heat coming from?

But all that cooling capacity should have you covered, I'd think.

 

the company said because i put it in myself and didnt use a tranny shop the warranty was void , im starting legal action for that as it dosent state that in the warranty , but no tranny shop wants to take the time to tear it down and document the problem . at highway speed it took 40 miles to get that hot and i was babying it the whole time .the tranny cooler by pass valve is on the pass side and goes between the out going cooler line and incomeing cooler line in case the cooler gets blocked or something there is a check valve to keep the fluid going to the coolers if a significant amount of back pressue is present it will open so the trans dosent over heat , however if its stuck open it dosent aloww the fluid to go to the coolers and causes it to overheat . i have pulled trailers for 20 years as i work for a carnival and know when a truck isnt running right and have never run into this problem before ,my 91 1 ton dually has 350,000 miles on only its second trans and original 460 motor [1 qt of oil per tank of gas ]and thats an early e4od and no one drives my truck but me, it makes at least 3 trips per week it pulls the heavy stuff . a typical trailer we use is 8ft by 20 -28 ft long 12'6 high and weighs in at 5-7000 lbs mt and then you start loading in all the stuff and it doesnt take long to get to 12,000, my 40' travel supreme house is 13,400 mt add my stuff [lots of tools!]and its pushing 15,000 next time your at a fair or carnival look at what they drive and then look at what they tow 52 weeks per year everything came by a pick up truck . 9 out of 10 will be a ford of some type. on my show they are all SUPERDUTYS AND WERE GETTING OUT OF THE 6.0 AND GOING BACK TO THE 7.3S THEY ARE SUPERIOR [i wish we could get a 7.3 with a 5r110 that would save a ton in fuel ]some of our trucks have over 300,000 miles on them and with lots of pm they will keep on the road a lot longer