I'm a firm believer that the 6spd has the greatest advantage over a stock auto towing more than 8500#. we have three work trucks, one is 03 QC flat flatbed 6spd with 99k tows great, the other is an 04 with an auto with 122k we've gone through 4 FOUR 4 transmissions after 50k miles towing no more than 12k# never modded these trucks the 05 is great so far still pretty new it's also a 6spd.

 

My 04 made it to 220,000 miles (91,000 with very heavy towing) before I had it rebuilt. My B-I-L owned a tranny shop......after a year of keeping a tally of which trannys were most often in for repair (had a bet on it) the 48RE was the least repaired tranny, This included Ford and the mighty Allison.

 

Looking at towing the weights you mentioned, either tranny would suit you well. Basically, with the smaller trailers weight, you probably would not notice it wagging behind, piece of cake to a Cummins. The 8500 trailer WILL be more noticable, but again the Cummins engine will be plenty to pull it without too much notice.

Buying used, it has been my experience that every time I have ever bought a used vehicle with an automatic tranny, it has had me in the shop with it rather soon after purchase. When I have bought a standard tranny truck used, it has gone much longer before maybe needing a clutch, which is really much less expensive than rebuilding an auto.

When I bought my 2006, I purchased it new, there were plenty of auto tranny trucks to choose from, but few standard tranny trucks, and the standards were NOT close to home. I went the distance to get the standard tranny equipped truck.

I would NEVER again own an auto tranny truck after owing the standard I have now. Hands down, my truck is the best towing truck I have ever owned, and my loads start at about 12K on the light side, and go to 22-24K normally.

CD

 

Towed with both and your right... Don't believe it

 

My 5th-wheel camper weighs approx. 16K and my truck doesn't have any problems towing it and we usually vacation in the Rocky Mountains. I had the auto tranny upgraded with Suncoast torque converter and valve body and it does great. I agree with the others, if you buy a truck with a 48re transmission, that has been well taken care of and not abused, it should be able to handle 8,500 lbs with no problems.

 

Towed with both also and its no contest, a correctly setup auto will run away and hide from a manual. Even the stock auto is better for less than max loads in all the pertinent areas.

Takes more to setup an auto correctly but once its there its a whole lot more enjoyable and effective than rowing the manuals up and down.

Anything at or under a 15k trailer the auto is just fine and will generally do you better on mpg than the manual. The manuals are finicky about heat, finicky about how you shift them, and the DMF is a joke.

The better trans is the NV5600 but you had better shift it right or it will cost you as the parts and hard to find and expensive. The G56 is a better shifting unit but its the same thing with it, don't expect to get any where in a hurry and don't push the shifts or it will be unhappy.

 

X2 never found an auto to my likeing

 

I have to go the other way and vote auto with the caveat of being set up. I put 115+k miles on a stock tranny and I tow a 10k TT maybe 25% of that time. Never had a problem with it. But I wasn't warm and fuzzy with it either. (BTW, trucks with a build date 01/03 or later were 48re... not 47re). After getting a Goerends, I have absolute confidence. While used to the manual, and in certain situations like mountain driving with a couple more gears to choose from I find the manual better, all things considered, I like the auto. With a lock up switch...

 

annabelle i hotshot for a living and my 04.5 with nv5600 went 300k + before i had it rebuilt. i haul heavy loads .i can gross out at 38k and i have been heavier .

 

Towing is a pleasure now that I have a built Auto with a triple disk TC. I wouldn't trade it for manual.......but I would rather tow with a manual than the stock auto with it's sloppy torque convertor.

..

 

I agree, the loose stock converter with a load behind it, just feels wrong.

 

Yep those autos are great after you buy a 50k truck then throw another 3 to 5 k at them.

I looked on the Cummins Forum and there were 4 threads on broken auto's.

I'd rather drive one around down but I have a car for that. If you're going to work it and keep it the cost of ownership of the 6 speed is way better.

 

Think that nails it...

 

If You Service Your Manual Tranny Fluids Regularly,,,,, And If You Tow Heavy,,,,,,there Is No Equal,,,, I"ll Keep My Bolt Action....

Auto Loaders Are Fine For The Loads The Thread Starter/weekend Warrior Spoke Of,,,,, A Beefed Up 48re Would Be The Way To Go If Auto Fills Your Bill,,,,,, 9k Is My Lightest Load,,,,17k My Max So Far, (24.5k Gross)

 

I searched for a manual so I wouldn't have to put alot of $ into an auto to hold extra power. (Still on the hook for a $1300 new clutch soon though.)
If I was towing all the time, I'd opt for a manual 6sp over a 4sp auto, but I'd take an Allison 1000 or a 68RE over a stick shift.
That said, buying used, I'd take the better overall condition truck auto or manual, but would factor in at least a new converter and vb.