i have a 2007 5.9 with a auto, how do i find out what kind of trans i have.

 

You have a 48RE transmission. The Aisin Warner 6 speed auto is used behind the 6.7L engine.

 

thxs for the info

 

^^^5.9's still have 48RE.
Just for clarification... only the cab and chassis 6.7l models get the Aisin. The pickup models, 6.7l get the 68rfe six speed. Why do the have two different six speed autos?? Who knows.

 

How good (or bad) is the 48re??

 

You can do a search and find a lot of answers either way. Some here think they are junk. My personal experience is that it is certainly not the best but not that bad either. I have had no problems at all with mine at 115,000 miles. But you can abuse it and tear it up too. It doesn't have 5 and 6 gears like the allison, I think that is a drawback, but I don't consider it to be a greatly flawed tranny either. I would say it is adequate. If you treat the stock one right, it should last a long time. If you are going to mod your truck, get a built one and it will last. If you mod your truck and thrash it, well it probably wont last too long... unless your name is Shane.

 

Thanks for the info!!

 

Ya, that sucker is going to go off like a bomb when it finally quits. lol

 

The 48RE should hold up just fine with stock power. Towing with light loads is also fine.

More power will lead to problems 1st with the TC, and if you go all out with power you'll need to upgrade a lot of parts.

Towing heavy will make you wish it had more gears. A lower 1st would be very nice.

The shifting is a little funky too, but if it really bothers you it can be helped a little with a VB.

Overall, it's a 50 year old design with an add on overdrive that will hold up if used reasonably.

I really hope to upgrade to an Aisin someday. Modern, tough design, a six speed and more sensible logic in a tranny that has not been cheapened to where it can barely hold the required load.

After looking around in mine I'm a little nervous to tow really heavy without twisting something off. But it has not left me stranded in 110,000 miles. The Cummins is such an amazing engine that its easy to forget what the rest of the machinery must do to keep up.


John

 

I think a tripple disc converter will extend the life of your stock trans a great deal. And also a valve body if you want a really awesome trans. If your going above 450-500 hp and/or tow 20k++ you should conside at least a billet input shaft. The converter will keep the trans a lot cooler as it won't slip like the POS stocker does. But the 47 or 48RE transmissions are pretty good if modified to fit your driving use.