still looking at buying a new truck, thought it was going to be a 5.9L 6 spd dually crew cab but now im realizing those are kind of hard to come by.

im having a hard time going away from a stick but i was wondering if you folks could give me some advice on how these bigger motors are doing paired to an auto trans. ive heard the typical cummins/auto stories that they dont really stand up to much more than stock power and im probably going to do a few minor mods but nothing crazy, maybe 150 hp over stock. i do a fair amount of towing and really prefer a stick but my brother in law can get me 08's CHEAP.

so i guess what im asking is pros and cons with autos vs 6spd's with the 6.7L motor.

thanks for any advice
mike

 

You should have posted this in the 6.7L engine and transmission threads, you will get more response.
I did a search in that sub-forum and this is one of the post that might help you decide.
https://www.dieseltruckresource.com/...light=spd+auto

I am using the Smarty and in the Smarty instructions they state. The stock 6 spd auto will handle up to 60 rear wheel HP. This is achieve using the CaTcher level 3, which I am using. Anything higher and used for a prolong use may damage the trans.

I tow in CaTcher level 3 also, hope this helps.
Jim

 

If you want to run 150 over stock, I don't think dodge, chev or ford can handle that without mods. That being said, there are some ferd guys running close to 500 on the stock tranny with the 6.4, but for how long remains to be seen.

Just my 2 cents, I love the 6 speed auto with engine brake. Dodge did their homework on that tranny and it works well. Its always in the right gear, there is no hunting and there are quite a few around that have been towing HEAVY for many miles without issues. The typical rule is you can safely run 60 hp over stock, that being said, ANY transmission can be wrecked by abuse, its all in how you drive.

 

Running 150 HP over stock will eventually cause the stock clutch to slip; so even with the hand-shaker you’ll need some upgrades sooner than later. You’ll be fine either way, get what you want.