I will try and make this Short as possible. I have a 96 F250 4x4 XLT Extra cab. Torque converter went out and I had the Trans Rebuilt. At this time I had the Thermostat replaced as the mechanic said the engine was runing to cold, and it was found to be stuck open. Every thing seemed fine until I started on my annual trip to Quartzsite pulling my 26 foot Prowler. As I was climbing the Chrico grade on I 10 out of Indio I had just passed several 18 wheelers and opted to get in the slow lane and manually drop down into second with the overdrive being off, to take it easy. With in what seemed to be seconds the trans felt like it went into nutral. I was lucky this time as I had made it to the first level area of the grade. $300 hundred dollars later and what seemed like hours I was towed to a local garage about 4 miles from where I broke down This was 1:30 AM. That Morning being the 14th of January the trans was taken apart, and it was found that the planitary gear had been waisted. One week later after the the trans had been rebuilt or taken apart 4 times I know had a Ford remanufactured E40D trans with 3 years or 36,000 mile warranty. Ok, I hooked up left the shop and stopped about 3/4 of a mile from the shop for dinner at the local truck stop on Dillion RD which took about 45 minutes. At about 7PM I was again on I 10 headed East about 3 miles later I shifted down manually with overdrive off andf it happened again, except this time there was a screeth from the trans. This time I was not as lucky as I stopped on a uphill; grade with the everything on the downhill side toward indio, scarry. I just picked up my truck on the 7th of January, from the local Ford dealer with another remanufactured trans and a bigger trans cooler, and still have to go back and get my trailer. MY local mechanic and I have desided to get it this Saturday and try and pull the Chiraco grade while monitoring the engine and trans specs. My question is after having a indirect conversation with a person that builds trans for funny cars and racers. His statement was until I replace the radiator in the truck I could put in a 100 trans and still have this problem because where the trans fluid goes through the radiator it is fouled and stops the circulation of the fluid when it starts to get hot. Can this happen? My thought on this is that my truck has always ran with the temperature showing just inside the normal range, and now with the new thermostat it is between the R and M. So, with the truck now running warmer it may be causing that part of radiator to close as the temp goes up on hard pulls? I really need some help on this as I'm really getting stressed about doing this all over again on Saturday and not wanting to destroy the engine either. Thanks Mel

 

That is definitely where the gauge is supposed to be, around the R or the M. There might be a restriction in the cooler but I would think that the fluid would get hot, it woud screw up the friction modifiers and oxidize and then you would get slipping bands and clutches, not a grenaded planetary assembly. Something is either not correct in the planetary, it is not being supported or lubricated properly or it is getting one hell of a shock loading, but this is purely an educated guess on my part. It's amazing to me that a 351 can shred an E4OD, they were tough enough to handle the diesels and the 460's...

Have you tried posting this in the transmission forum also?

 

I guess I left out that it is a 460. I threw my thoughts to the mechanic that had rebuilt the trans in October. He had said from the start (when I called and told him that his rebuild had went) it was a lube problem. I'm going to his shop tomorrow and he is going to hook up a flow meter to the trans and along with the scanner pluged in we will be able to see what's happening when we pull Chiraco grade on I 10. At least it will be daylight this time. I thought I was in the correct forum. I will try and find the trans forum. This truck and trailer have been up and down the Siera's over Mongomery Pass to Gabbs many times, and yearly trips to AZ with out a single problem for 6 years. I guess it was it's time. Thanks for your rersponse Mel

 

Looks like your mods put the post in the right place, maybe some of the transmission guys can answer your question better. The lubrication thing seems logical, it's obviously something outside of the transmission...

 

If you haven't replaced the trans coolers they are plugged and causing the lube problem. The lube for the rear half of the trans, including most of the planetary gears, goes through the cooler. No cooler flow, no lube to the gears.

 

When ford put in the last trans in I had them put in a larger cooler. Tomorrow will be the test. We will go up chiraco Summit without the trailer first, and then with the trailer. Mel

 

A larger cooler is not the solution. Replace the cooler in the radiator then add the larger cooler. Any restriction in flow through the coolers will result in rear planetary failure. Use only a high quality add-on cooler and make sure it will flow plenty of oil. Some low cost coolers will restrict flow due to poor design.

 

Well, went to my mechanic's shop to hook up the flow meter to the trans,. After the line was connected to the trans side of the return line, the meter didn't work. After he made several attempts to get power to the meter it was found to be dead. So, he took everything off and desided just to go with the scanner connected. While he was parking cars in his garage I swung around to the front of the complex, noticeing a sound like a plastic tie going around the drive shaft hiting the frame. I brought this to his attention, but we couldn't find where the sound was coming from. Didn't seem overly serious at this time. I picked him up saturday and we were headed for Chiraco Summit before we picked up my 26 foot prowler at the other Mechanic's shop at Indio. The truck and trans did fine. I was a little shakey when we passed the two spots where I had broke down 3 and 4 weeks earlier. Engine temp about 190 and the trans was about the same and less. Came back down the hill hooked up and went for it. The hottest the trans got was about 210 and about the same for the engine. Everything worked fine, only shifting down to second when I got behind a 18 wheeler and couldn't get around. We ran all the way to Chiraco which is about 26 mile pull with some long level run areas. Now I just have to figure where the clink is coming from, could be missing a needle bearing from the u joints as many times as it was taken down. I just hope it's not part of a snap ring from the trans ao something in the torque converter, but I don't think I would have got my trailer home if it was. I thank you for all the response. If you have any more thoughts let me know. This is beginning to be the never ending story. I think I will get a scanner instead of a trans temp gauge. Mel