So I just noticed this issue the other day. When I am above 60 mph and I go to increase the speed, AKA when I am trying to pass someone, my engine will rev abnormally high when I put my foot down slightly or all the way in order to downshift to increase speed. If I gradually put gas down, I will gradually speed up, no issues (other than accelerating really slow).

Last year, I rebuilt my transmission after the 3-4 clutches burnt out. I replaced everything including all electronics, all clutches and steels, seals, O-rings, servos, etc. The only hard parts I did not replace were the sun shell, the input drum, the pieces to the front pump, the planetary gear sets, etc. and finally the torque converter.

I've driven this truck for over 9000 miles since I rebuilt the transmission and the shifts are crisp and clean at any speeds below 60 mph (highway speeds). I've noticed that the RPMs required are slightly higher than what they used to be, but I was thinking that was on account of the fluid being cold upon start up and still remaining fairly cold will running (New England weather in the winter).

Last week, I also stalled on a hill at a stop light for no apparent reason. I read up on it and hoped it was just a fluke, but it happens that a torque converter issue can cause that. I am wondering if this is also a sign on top of the high RPMs issue of my torque converter finally kicking the bucket.

I know I should've just replaced it when I did the transmission rebuild, but I was stingy and didn't listen to my gut on it. That and the adapter housing, which after much troubleshooting, is in fact cracked and was the cause of my leak for the last 2 years.

Here are two videos of me on the highway (I know, someone's going to have to call the cops on me for having my phone out while driving). Let me know what you guys think (I've already ordered a new torque converter and will be replacing it next week regardless). Thank you.

 

I should mention that I have not seen any codes from the scanner whatsoever.

As for the leak, I have been topping off the fluid every week or so and making sure it's at the proper level. I just did this again this past weekend.

 

False alarm, thankfully. The fluid level was extremely low (to the point it was getting too hot). This crack has propagated over the last few weeks due to the cold weather and now the heat wave we are getting. I can't keep up with the leak like I used to be able to. I have the replacement adapter housing, I will be switching them out this weekend.

FYI for anyone with similar transmission problems. If you have a leak and notice issues, double check your fluid level before making any other assumptions. I don't want to know how much return shipping is going to cost for an item this heavy...

 

Thanks for the update.
The cause of a slipping converter is often low fluid. Even one quart low can be noticeable.

I'm closing the thread since it seems to be resolved. Niko - PM me if you want me to open it again.