So I think it finally happened. On my way up to hunting camp to clean up after season has finished. Noticed the truck kind of shift up and down quickly. I thought to myself, HUH never done that before. I get up to the dirt road going into camp and switch it into 4wd. Get back in the cab (manual hubs) and glance over at my pillar gauges and notice my transmission at 250*. By this time I was commited to the snow covered road cause i had a trailer on my tail and couldn't get turned around.Got back to the roadside and added 1 qt of fluid which seemed to make it a little better. got to the local NAPA and added and additional quart. I was really having a hard time telling wether the fluid was low or not, I really didn't want to over fill the tranny and make a bad situation even worse. Limped the truck back to home and took it directly to my friends shop. he thinks the cooler or line is clogged. I don't knoiw enough about this to even venture a guess. this site has helped me out more than once and I'm hoping you can help me again.
I changed the tranny fluid this summer with DEX/MERC fluid and all has been fine.
155K miles.
Symptoms: Feels like tranny slipping and the RPM tack bobs up and down when slipping. A slight whining noise possibly, its hard to tell with my Intake and 4" MBRP.
I don't have a good feeling about this. I think I will be checking out BTS site soon.

 

Mine did the same thing on the beach pulling a trialer.Dumped three quarts. I let it cool added fuild drove it for one more year and then had to replace the trans.But mine shifted fine after it sat a couple days while camping. When I got it back I dumped the fuild and replaced filter and fuild every thing seemed good.Had 100 000 miles on it at that time. Good luck.And do you have an after market trans cooler or 6.0.Because I bet if you don't in the mountains at slow speeds it always got hot you just didn't notice it. I didn't still I got gauges. I know you got gauges but did you always take it in the mountains.Mine is an E99 auto and it didn't go thur the radiator.

 

You can test the flow rate. Here is the link: http://www.dieselsite.com/index.asp?...ROD&ProdID=205

 

The tranny has a pressure operated bypass valve that operates if the cooler or cooler lines gets clogged. When this happens it bypasses the cooler and runs hot. Something to consider.

The bypass valve and tube are located on the passenger side of the tranny.

 

Same thing happened to by buddy's older F250. He was pulling his camp trailer up a couple of miles of up hilly logging roads in 1st and 2nd gears.. Heated the trans and dumped about 4 quarts of oil on the ground..
Be sure to change out that old heated oil along with the torque converter.. and you might be OK for a while..

 

What would cause a clog or plug, to my way of thinking it's all liquid in there. From what I read on Dieselsite, you remove the return from the cooler at the tranny, start truck for 15 seconds and then measure volume. Should be >32oz. if I read correctly.
Are the NAPA coolers any good? I don't mind ordering one from dieselsite but if they aren't that different why not go local with lifetime warranty.
I also here frequently the 6.1 cooler is good, whats the advice with that one??
Thanks for the info so far.
Glenn

 

I think you want to test for flow on the supply and return side to determine the problem. If you are not getting adequate flow on the supply side that points back to the transmission.

 

99 times out of 100 what clogs the line or cooler are parts from a tranny or torque converter going bad. The bypass valve is supposed to prevent a catastropic failure due to overheating. If there is no flow through the cooler the rear of the tranny fails very quickly because it will overheat severely do to the lack of fluid. The bypass valve at least keeps fluid circulating through the entire tranny.

If for some reason the bypass valve is partially stuck open or faulty not all the tranny fluid would be going to the cooler.

 

So what you are telling me is that my TC is about to crap out on me. Correct? I do alot of towing in the Summer time with my TT. rather get this all fixed up now instead of on the side of the road in East overshoe nowhere.

Being that the tranny and cooler are a closed loop I should get the same flow in onces from both the inlet into the cooler and the tranny return. correct?

 

That certainly seems right. I sure hope whatever it is it's not too damn serious.

 

Originally Posted by Billyclub
So what you are telling me is that my TC is about to crap out on me. Correct? I do alot of towing in the Summer time with my TT. rather get this all fixed up now instead of on the side of the road in East overshoe nowhere.

Not trying to tell you anything. Just answered your question. Think positive.

Sorry, not trying to be confrontational, just my nature to be direct. Appreciate the input, I should know more today when the truck gets onto a lift

 

It would me my guess they won't find any problem.
The trans just does not like to get that hot without dumping fluid out the breather.. You might have shortened the life a bit however.. But, like i said before, change the fluid including the torque converter..

 

I didn't take it as confrontational.

I just didn't want you to think that I was saying your tranny was shot because there is no way for me to know that.

 

I'm a big time hunter like you and I pull a 31' TT to camp. Even though my transmission was good I had Brian at BTS do his thing because I didn't want to be stuck out in the woods due to a bad trans after increasing my motor's power. He's worth the money.

Give him a call at:

Brian & Patti Thompson
P O Box 246
Lead Hill, AR 72644

Brian's Truck Shop
14991 Industrial Park Drive
Lead Hill, AR 72644
Phone:870-422-(FORD)3673
Fax: 870-422-3675

 

I had a similar overheat on my 4R100 when I first got my truck and trusted the stock trans temp gauge. By the time the stock gauge finally bothered to show high and the OD light got to flashing, the fluid was brown and glittering like a bass boat. I flushed the oem cooler with Kooler Kleen, added a big aftermarket cooler, replaced the Magnefine filter, and got new fluid in there. I deleted the bypass, but in hindsight I should have left it on. Also put in a Factory Tech valve body seeing as how I was in there. And real gauges, finally. Two years and many miles of towing later, all is well. Hottest I've had it since is 235* for about 20 minutes under very tough conditions, but no pukage, and the fluid is still sweet and fresh.