Can a 400HP truck carry 35K 53ft van load on steep grade easily?

2:47 is a flat land gear set... It will fall on its face going up grades. It will get up the hill just fine, but if its much of a hill at all it will be slow... Very slow.

 

Think of the sprockets on a bicycle...if they were both the same diameter, the amount of force you pushed onto the pedal would directly relate 1:1 to the force the tire pushes the ground. Now, if you make the front sprocket small in diameter, you would pedal faster than you would at 1:1, because the ratio would be less, like .75:1. Now, if you make the rear sprocket smaller instead, the ratio would go the other way 1:2. So, for every 1 turn of the front sprocket, the rear sprocket would turn 2 times.

I know the ratio is teeth count for the the ring and pinion, but I'm trying to offer an easier visual to understand the principle...there's alot that goes into it. To find the best ratio, you need the torque curve of the motor, transmission gearing, differential ratio, tire size, and cruising speed.

 

Speed won't change much, you'll just need to drop more gears in the transmission to compensate.

 

Until you run out of gears

Or need to start on a hill.

4.10s are my choice.

 

515 worked good for me.

I think I'd prefer 550 though.

Anything more then that would just be too much torque on take off and slow speeds.

 

2.47 is direct drive it equals out to roughly a 3.36 ratio with double overdrive .. a direct drive is more efficient but puts full torque through driveshaft. Whatever gear a 3.36 would be in is the same gear a direct drive 2.47 would use.. think of it this way a 2.47 the overdrive is in the rearend 3.36 the overdrive is in the transmission.. start ability should be the same because of the different ratios in a direct drive transmission…

 

6V71 going up to Reno NV? LOL.. hours of fun.. no wonder I'm deaf! lol

 

My dad got his 1st over weight ticket in a 9500 with a 238 and a 10 speed Lol.

 

the question that has to be asked is this - what qualifies as a steep grade?