Low Boy 60 ton .

The highest torque rated 10 speed that I know of is a FRO-18210C. The low hole is a 13.75:1 ratio.

If your C15 is set at 1850 you could theoretically get by with it. That said, I don't think anyone would spec a 10 speed for heavy haul, unless maybe they had an auxiliary 3 or 4 speed behind it.

The thread title includes 60 ton lowboy. With a 60 ton load you would likely be grossing at least 170K.

I guess, without being snarky, I would think folks would want to know a lot more about your plans. The fact that you are asking this question indicates a general lack of knowledge in regard to heavy haul. That's ok, nobody was born knowing this stuff, but it would seem prudent to get yourself into a situation in which you were hauling 80K to 100K gross at the most and learn as you go.

To get back to your question, it is possible to get by with a 10 speed at 120K gross, but you won't like it. A lot would depend on your rear end ratio. 3.90s to 4.33s you might survive. 3.55s or longer and I believe you will have an expensive education.

Give us some more details. There are some savvy heavy haul guys on here. They may not tell you what you want to hear, but they will give sound advice.

 

You may want to post this in the heavy haul section, or perhaps it can be moved.

 

I hope you've at least got low gears in the rear ends. Somewhere in the 4.10 to 4.56 range.

 

A, C model 10 speed has a good low gear but a don't think the A and B model are going to work at all.
Also what rear end gear does it have 3.70 or lower is what you need even with an 18 speed , while it can be done with truck that is not set up to do the job, until you can't get rolling at a stop light on a hill then what?

 

I have done some work in a friend's truck in the 110k-125k range. Truck has a 6NZ C-15 making 600HP/2,000TQ to the wheels, a 10 speed and 3.70 gears and it wasn't easy even for me with several years of experience. Getting started on just a 2-3% grade was a little rough. It is very easy to make a mistake and break $20,000 worth of parts.

 

It worked for years with 8LLs and 15 speeds with the 425s or 400s, personally, EYE would do it, but there’s no way I’d put some clown driver in a light spec truck to do it,

if you are doing it day in and day out I would definitely toss that 10 speed in the scrap pile

 

both the 8LL and the 15speed had much lower "crawler" gears for lifting the load and if any had final drive gears anywhere near 3.90 I would be very surprised. Most final drive sets were 4.56 or larger, the heavy truck I learned on in the late 70's and early 80's had 5.29 gears and a 5X4 transmission set with a "warmed up" big cam 350. Our support and lighter haulers (up to 7 axle) could be 13 or 15 speed and the fast trucks had 4.11 gears. The engines of that time produced nowhere near the torque of todays engines and most ran at 2100 rpm or more to produce their horsepower. There were some specialized haulers that used Cat or Mack V8 power but they were moving super loads with 48 or more tires and loads grossing 250,000lbs or more.

 

What is an 8LL?