Shortest Wheelbase For Tandem Tractor?

Hello all. I've been searching for measurements on what the shortest wheelbase would be for a tandem axle tractor, and I'm having a hard time finding numbers.

I have a 1996 Freightliner FL70 8.3C Cummins with a 9 speed, not exactly sure of the drive ratio. It's a single axle dump and I'm considering removing the box, and adding a fifth wheel and a drop/pusher axle to it. The wheelbase, as it sits, is 180" center to center. 12K front axle, 21K rear axle on springs, 11R 22.5 x 8.25 all around. If I add a drop axle, at 40" spacing, it would put the wheelbase at 160" to the center of the tandems. Is that too short a wheelbase for a fixed/non steerable lift axle? Would a steerable lift be best? Is that too short PERIOD?

My intention is get a dump trailer and run around local, much the same as I do now servicing my own construction and landscaping projects customers. Pretty much under the radar, not worrying about too much, if you get my drift.

This is a great little truck. It was a San Diego County Road Department truck that I got in 2012. It has less than 90K miles on it, and is solid. I think I can the get truck/trailer weight to come in around 25KLbs, and I'd like to be able to haul around 22 ton or so of material.

Just a little more info on me and my experience trucking - I owned and operated a triaxle dump and ran interstate for a number of years. I'm not looking to do that. I'm not buying another truck. I know what I have, I own it, the overhead with insurance and maintenance is negligible. I'm not looking to make a ton of money with it. It's not my primary source of income. I'm just thinking that for under $20k, between modifying the truck and buying a trailer, I can make a setup that will allow me to keep doing what I do with it already, and make the truck more versatile. Anyway.

So, my primary question is again - would 160" wheelbase (center of front axle to center of rear tandems)be too short for a tandem axle tractor, considering that the forward rear could be a steerable lift?

Thanks for any insight.

 

I appreciate everyone's input. To reiterate, my primary question was if 160" wheelbase is ok for a tandem axle tractor, and since it would be a drop axle, if given that short of a wheelbase, a steerable lift would be best. Thanks in advance for the input.

 

I really appreciate you taking the time to send me your opinion. Have a blessed day!

 

Thanks for the advice. I had a triaxle and ran interstate with it for a while. I didn't find it to be profitable, at least not for me. Like I stated, I only run around local and service my own customers. The insurance, regulations, and paperwork required to be in compliance are minimal compared with how I've ran in the past. Furthermore, it's not my primary income at all and I'm the only one who drives the truck. If I was driving 375 mile a day at 80K all day, yea, that's ridiculous to be that hard on a truck that's not built for it. To do a load or 2 a day a few times a week locally at maybe 73K- not concerning. It's flat here, and with 3 extra axles worth of brakes and an exhaust brake, it'll stop beautifully.

I've learned that I'd rather keep what I have and own, and make into something that will work, instead of buying another headache. I don't have the time or desire to screw around with buying another truck. I've carved out a niche where I live, and I'm just exploring how I can squeeze a little more out of it. Thanks again for your input.