cummins makes a excellent motor but all i ever hear is the trannys are problematic has anyone found out why they have these problems? i herd the newest ones have clutch issues. just trying to get some light on this no one has ever given me a straight answer besides they are just junk ect (which i dont believe) might be getting a cummins here in the future thanks

 

Because the engine makes so much torque it just tears them up

 

kinda figured that seems like any Chrysler product has tranny problems tho. few people i know had them go at 100k

 

my fathers stock tranny has 235,000 miles! daily driver, when i drive it he can tell i beat on it though :p

 

The problem with most of your older autos...46rh/47rh/47re were all designed for gas engines...the 47re was utilized for the V10 and the cummins. The two biggest problems were line pressure and the torque powerband. A gas motor idles higher, thereby creating more line pressure at idle, which allows more fluid to cycle through the transmission, keeping it cooler, by pulling the hot fluid through the tranny and coolers. At idle, the diesels didnt have a high enough idle to keep those same line pressures, so not as much fluid moved through the tranny, leaving more heat in the tranny. The other issue is that diesels create much more torque at a much lower rpm...the transmissions were designed for gasserz, and werent engineered to hold up to the higher demands of torque placed on them by a diesel application.
As far as the newer ones, well, the 48res werent bad from the factory, but they werent designed for above factory horsepower applications. Upgraded, they can hold up to 600-800 hp easily.

 

i have 103,000 on the stock tranny and it has a towing life haven't killed it yet but if it goes it getting a aillson bolted on to it that for sure

 

okay that explains alot. that was really stupid of dodge to put a gas tranny on a diesel..

 

The trans was built for the diesels, it won't bolt up to a gas engine.
Issues of failure are, like said, not enough line pressure. A shift kit helps this.
Adding clutches is a big help too. Then you need a tighter converter to keep the engine in its torque.

 

I know mine is still holding up decently with 143k on the clock.. but when it goes im going to goerend in Iowa to get mine built or buy a built one.. or I'm doing the 6spd swap... I'll be happier with the 6spd