Hello, I am a first time site user. I have a 32' three axel trailer with a race car inside. The total weight is 13,000 lbs. I am pulling it with a 2002 dodge 2500 with a 5.9 cummins. I am really pushing the towing limit here. So, I am looking at a 2002 Kenworth T-300 'bobtail' truck with a Cat 3126 and 6 speed allison trans. The rear end is 4:63. How can I find out what the pulling power is of this vehicle before I purchase it and convert it to a 'motorhome'? Thanks, Rich

Greetings Army Man. A few humble opinions: Cat engines can be great, but I can't speak fo the 3126. Stay away from Allison automatic transmissions. A 4.63 rear will probably provide pulling power but will be screaming engine rpms up and down the highway. The KW T300 has lots of limitations; go for a full HDT. The heavy duty truck, class 8, comes with million mile engines (maybe at a price)and if you don't want their big, stick shift trannys Eaton auto shifts or Arvinmeritor Freedomline autoshift transmissions are worlds apart from the Allison automatics, and get you mpgs you'd never believe. Patient shopping around, truckpaper.com, racingjunk.com, etc. will get to some reasonable prices, but sure check out thecondition of the rig. Big repairs on big rigs are not cheap. Keep looking and good luck.

This message has been edited. Last edited by: medent,

Army man might be OK with that rear end; the top TWO gears in the Allison are overdrive gears; i think .75 and .60, or thereabouts. But you are right about Class 8 trucks, besides which they are usually CHEAPER simply because there are so many of them, WAY more in quantity than Class 6 or 7. You can usually get a 5 or 6 year old Class 8 with about 600K miles for about $25K, more or less, which is less than a same-year Class 6 or 7, which by the time they have more than 300K miles are pretty worn out. So unless that KW T300 is a real killer deal, he might better stick with Class 8 trucks, with the wider selection, more power, and similar fuel mileage.

Thanks for the advice guys. I can't go with a HDT. I drive an 18 wheeler tanker truck on the streets of Los Angeles and when it's time to drive for pleasure....I want a break! I've found a KW T-300 with a Cummins 8.3 and a Fuller 6 speed, 3:89 rear end,(class 7). I need to find out if I've got enough umph to pull my loaded trailer. I'm going to ask to hook it up for the weekend and I'll see how it feels. I don't like to keep the r's up either. Rich

Hey Rich-

Driving a medium with spring suspension and non-air seat(the way most mediums come) will beat you WAY more than a Class 8 with air suspension, air ride cab, and air suspension seat. They are both equal in shifting ease. Don't count out the big rigs. They are actually BETTER set up for comfort than most of the mediums. You feel "beat" with your work truck because of the loads you are pulling, that fatigue you through the day. The same truck will be a breeze to drive pulling an RV because it is WAY lighter than some commercial trailers are when nearly empty. Give this some thought.

Hey Rich,
Gary is right! I just got back from a 14 hour one way trip and I felt refreshed enough to go right on to work. The wife took over for the last 1/2 hour so I could catch the last of the race while I got dressed for work. With a smaller class of truck I would have been beat.

Wick