Big Loads - Post Photos Number 2

Going to switch out of the Star already?

 

I am trying to find out any issues that might be having like terrible road speed or slow gear or range changes in the cold

I am looking at 210-220k gross weights

 

Thinking about it @Rugerfan

 

I don't think you will have road speed issue with the allision they have a real tall OD dump trucks will run 70-75 with 5.02 gears and the just the Allision. You will find the warranty package is better if you stay all Mack power train 18spd LR is a good trans. they are pushing that 14 spd M DRIVE for heavy haul its super smooth but I'm not sold

 

Rontonio, I realise I was in a different situation than your highway truck, but I used to haul logging equipment in the mountains on Vancouver Island. Had a KW , 3406B, 6 sp Allison , 4 speed air shift spicer 1241 aux. I could start off with a large roadbuilding excavator on a 10-12% grade with no trouble. When on the pavement I put the aux in O/D or direct and had good road speed. I only had a 2 axle 60 ton L/B but hauled some big loads, biggest was a fully rigged grapple yarder. I found the Allison to be a very tough trans, and today they are probably much better.
When I looked at pictures of your rig, I wondered how you get it started on a steep hill with a full load.

 

That kind of experience is what I am hoping for.

What rear end ratio were you running?



To answer you question, Well that is a long story that ends in tears and wreckers.The hill starting is the only reason I am considering running this combination. i have for a solution that will start at 200k gross on a grade as steep as 15%

The solution they have come up with is a very deep rear end ratio and using the overdrive gearing in the 4 spd for normal road conditions.

 

Is it hard in the rearend to being spinning that fast most of the time?

 

I would sure think so. Oil changes on them once or twice a year might be a good idea. I'm sure they would generate a considerable amount of heat.

 

I am not sure to be honest. They are suggesting 6.13 or 5.63 running through either 1.59 or 0.83. I am not concerned about being gearbound to 70 mph as I almost never run faster than 65 anyway. I am worried that winding up the torque convertor from a stop to road speed will be ungodly slow - making running through stop lights evn worse than it is now. Running the 17 miles of beltway 8 in Houston could take a year.

The solution will have manufacturer warranty - so I doubt they will approve a solution that will flat out not work. I did let them know that it can take me over an hour to run up or down a long grade, so they need to verify the cooling solution.

 

I had Rockwell 5.29 (58000 lbs) , truck only had go with a small drive lines and I found the allison saved breakage. Have you thought of putting a deep under in the aux? If you had to use it once in a blue moon it might be worth it. With 2,3,4 in the aux you still have lots of options. The other trucks I had were rigged with 10 speed mains, 4 speed aux with deep under, no match for the allison. If you used a deep under in the aux, couldn't you go with a more standard ratio. The reason I mention that is I had one truck with Rockwell 6.44's and went one went had to replace both because of parts availabilty.