Attention: TDR Forum Junkies 
I have an 07 3500 with the 5.9 motor and the 4 speed auto transmission.(not sure of the number on it) The transmission is a Jasper rebuilt and was installed 3 years ago. Waranty on it ran out a month before all this started. (Typical) so here is the run down of what has happened with it...
First time... Suddenly lost reverse.
Fix... The ring on 3rd gear cracked(40 years of doing this he's never seen this happen before) Replaced it and all new seals and gaskets and sensors. Pretty much a rebuild kit. Ran great for about a month.
2nd time... Started shifting hard into second gear
Fix... Reset sensors ran great for about 6 months
3rd time... Weak reverse shift hard into 3rd and overdrive
Fix... Found a scored spot on the housing. Replaced the housing and valve body.
Ran great and shifted perfectly till the transmission heated up then it was back to the exact same thing.
Back to the shop The next morning. Which is the 4th time... The exact same thing... Shifts fine early that morning. About 15 mins later... After coming to a complete stop. It shifts into 2nd normal. 3k rpm shifts into 3rd. Shifted into 4th a hair late. Then wont shift into overdrive until its going downhill and there is no load against it... About 70 mph. And reverse is really weak. Fine on flat ground but lugs if there is a grade at all.
This transmission has been torn apart and gone thru and rebuilt at least 4 different times and it is still not right. Any ideas on what it could be. All the big stuff has been replaced... At this point we are just about dumbfounded.
First time... Suddenly lost reverse.
Fix... The ring on 3rd gear cracked(40 years of doing this he's never seen this happen before) Replaced it and all new seals and gaskets and sensors. Pretty much a rebuild kit. Ran great for about a month.
2nd time... Started shifting hard into second gear
Fix... Reset sensors ran great for about 6 months
3rd time... Weak reverse shift hard into 3rd and overdrive
Fix... Found a scored spot on the housing. Replaced the housing and valve body.
Ran great and shifted perfectly till the transmission heated up then it was back to the exact same thing.
Back to the shop The next morning. Which is the 4th time... The exact same thing... Shifts fine early that morning. About 15 mins later... After coming to a complete stop. It shifts into 2nd normal. 3k rpm shifts into 3rd. Shifted into 4th a hair late. Then wont shift into overdrive until its going downhill and there is no load against it... About 70 mph. And reverse is really weak. Fine on flat ground but lugs if there is a grade at all.
This transmission has been torn apart and gone thru and rebuilt at least 4 different times and it is still not right. Any ideas on what it could be. All the big stuff has been replaced... At this point we are just about dumbfounded.
