Going to buy.

[biggdadd58]

Hello, I am looking to invest into a tow vehicle. A 1 ton diesel dually with a standard transmission and engine brake. My questions are these.

Is the standard the right choice or will the automatic hold up?

What gears are you running and what fuel mileage are you getting?

Do they offer an engine brake for the automatic?

Pros and cons will be appreciated. I am towing a 34' gooseneck trailer when loaded weighs 18,000 lbs.

 

[14hemiexpress]

From my research the manual is rated lower towing ability. The manual is limited to the 3.42 and 3.73 ratios maxing it out in the 18k range depending on configueration. The 3.73 with the rf68 auto maxes out in the 19k range. The Asian with the ho cummins and 3.73 maxes in the 23k range. Depending on the use of your rig mostly loaded or mostly empty. If your mostly empty I recommend the auto 3.73 if your willing to spend the extra 2g on the Asian its a really stout trans from my research. If you plan on pull more often than not the go with the 4.10 and auto. The 6.7l has the exhaust brake across the board. If you could give us a little more insite on how often you plan to tow and the terrain you plan on pulling through we could better our advice good luck and once you pull the trigger we want pics.

 

[spoon059]

The auto transmissions are fine, they are rated for more HP and torque. I bought mine used because money was an issue for me. If you can afford it, I would get the Aisin transmission. That is a much heavier duty transmission than this truck needs, but its a great option for a minimal upcharge. Otherwise the 68RFE is a fine transmission, but its about maxed out at its capabilities with a stock Cummins engine. Mine handles great when towing my 8500lbs trailer.

I have a 2500, so my mileage will be higher than yours in a dually. I get 21 or 22 on the highway at 75mph, but I have an Edge JWA module... not sure if that is helping with higher mileage. That is with 18" tires and the stock 3.42 gears. Towing I get between 12-14mpg, depending upon terrain. I'm towing half the weight you are though.

Yes, the auto has an exhaust brake and it works great.

 

[MADDOG]

I agree...the Aisin transmission is the way to go with the Cummins if you are towing that heavy, especially if you planning on towing over mixed terrain. It is rated higher than the manual transmission by about 1,000 pounds (GCVWR) depending on how the truck is configured.

Performance, capacities and MPG can be affected by the gear ratio as you know. Load capacity varies by truck configuration as well. A few questions for you:

Crew Cab, MegaCab or Standard Cab?

2x4 or 4x4?

Long bed or short bed?

 

[mtofell]

The auto transmissions are fine, they are rated for more HP and torque. I bought mine used because money was an issue for me. If you can afford it, I would get the Aisin transmission. That is a much heavier duty transmission than this truck needs, but its a great option for a minimal upcharge. Otherwise the 68RFE is a fine transmission, but its about maxed out at its capabilities with a stock Cummins engine. Mine handles great when towing my 8500lbs trailer.

I have a 2500, so my mileage will be higher than yours in a dually. I get 21 or 22 on the highway at 75mph, but I have an Edge JWA module... not sure if that is helping with higher mileage. That is with 18" tires and the stock 3.42 gears. Towing I get between 12-14mpg, depending upon terrain. I'm towing half the weight you are though.

Yes, the auto has an exhaust brake and it works great.

You must have a nice wind at your back.... 21/22 @ 75MPH? 12-14 towing 9K? These numbers are quite a bit higher than being reported on towing forums. I'm not trying to start a war but don't want the OP to get his hopes up either.

I'm not in a diesel any longer but my old truck (06 Duramax) would see about 17 @ 75mph empty, maybe 20 if totally flat at 55mph. Towing about 8K I'd see 10-11 if flat at 55mph. My truck was one of the last w/o DPF and other stuff and have read those emissions hurt MPGs.

 

[14hemiexpress]

I agree...the Aisin transmission is the way to go with the Cummins if you are towing that heavy, especially if you planning on towing over mixed terrain. It is rated higher than the manual transmission by about 1,000 pounds (GCVWR) depending on how the truck is configured.

Performance, capacities and MPG can be affected by the gear ratio as you know. Load capacity varies by truck configuration as well. A few questions for you:

Crew Cab, MegaCab or Standard Cab?

2x4 or 4x4?

Long bed or short bed?

From the towing chart a reg cab 2wd long bed 3.73 manual trans is rated at 18510, and same truck with the HO cummins and the Aisin is rate for over 23k so there is closer to a 5k diffsrence. The 68rfe is 1000lb difference.

 

[biggdadd58]

Thanks for the input. I am looking at the crew cab with the Aisin tranny. Need to find that pot of gold now!

 

[Stangshcky12]

The exhaust brake is much more effective in manual trans trucks than auto

 

[BossHogg]

The exhaust brake is much more effective in manual trans trucks than auto

That is a strong statement that needs to be supported. Have you driven a late model in tow/haul mode and the EB on pulling 15,000 pounds?

I don't know if the EB should be more effective than what it is now. Seems to be a well tuned system that offers up around 250 BHP.

 

[Ratket]

the exhaust brake is fine on a automatic. For your sanity get the auto. It will just make daily me eaiser for u and the family. If it is just u and u want a stick then by all means.. but for the love of god test drive both!!

 

[biggdadd58]

Brought it home last night. Can't seem to locate the block heater hookup...not sure if it has one. I was told it also had navigation but I can not seem to locate that either.

Can someone tell me how the Tow/Haul mode works and if it needs used. I have the Aisin transmission with the 3:73 gears.

Is the air bag suspension worth the money?

Has anyone purchased a locking fuel door for a dually and where?

 

[14hemiexpress]

Tow haul should be a button just under your stereo. It changed the shift pattern in the transmission, it hold gear longer and down shifts early and increases line pressure to reduce slip and keep the trans cool. I use it anytime I have a trailer with a load on it. A empty trailer i don't typically use it.