Question about rear gear ratios and tranny gear ratios

OK, I'm not really a trucker but, my older (smarter) brother and I are farmers and we need a truck to haul grain to the local grain elevators or ethanol plant. We would never go more then 30 miles from home. Our routes would several turns. We will never run on the interstate. We just need a day cab. We found this truck:

http://www.truckpaper.com/listings/...7&dlr=1&guid=1252AF0813BB441488FE17C5EC3A4D63

We looked at it and was very impressed at it's condition. It also has been serviced at the dealer all it's life and we can see all the service records on it!!! (That's a plus!) All the other day cab trucks in our area have been beat to death. So what's the problem you may ask ??? The 3.07 Rear gear ratio. Heck, my brother gave money down on the truck friday and canceled out on monday, (today). Just because he was afraid of the gearing. Well, the salesman called him back and said that because this truck has a Rockwell tranny with a 10 speed and deep "low hole" that the start ratio was 46 to 1. Using his formula and comparing it to other trucks in this area he's right! None of the others are as deep. He is saying that the changes between all the gears are all about 35 to 1. AND, that if we bought a truck with lower rear gears, BUT, it had a Fuller 10 speed that the top 10'th gear in a fuller is a OD. So, his argument is that this truck will still run fine for us. Taller rear gears but, lower tranny gears. We may need to run in 9"th some of the time but, on short trips so what. Were not in any big hurry.But, we do need to make 50mph in short runs and 60mph on the long haul pulling 80000 lbs. So is the salesman blowing smoke or what?

I really like this truck and I am the one who will be driving it 95% of the time. This one is a Cadillac or Lincoln. But, will the gearing work for us?

Hope there is someone here who can help us understand all of this . Thanks for any and all replies you can offer.

Caveman Charlie.

 

Doing some looking on the net we found that trucks with a 10 speed overdrive have rear gears of 3.73 or 3.55. So basically they have 9 gears between there start ratio and 9th gear which is1 to1. This truck has 10 gears but, it has a lower first and each gear is spaced 35 % higher then the one before. So, it has 10 gears in the same place that the other trucks with a OD tranny have 9. Meaning um.... oh heck I don't really know. Meaning that our first gear gives us a startability (and yes that is a actual word they used to describe it) of 46 to 1. Which is lower then the other trucks with a lower rear gear but, higher tranny gears.

It be great to find one with deeper rear gears and this tranny. But, like I said we looked at about a dozen trucks and this is the best one we can find. For both it's condition and it's pulling capability.

Now, some of the truck salesmen say we should have a startability of 50 to 1. Just to get it out of the soft corn fields. But, I've driven a lot of underpowered trucks out of the field before and I know some tricks to doing it. Besides we always park in the same spot and haul the grain to the trucks using a grain cart. After the first couple of loads we have a road packed down from driving in the same spot every time.

 

Well, he bought the truck today so I guess my whole question becomes moot. I will find out how well it works one way or another.

No hills around here. All we have is flat land covered with corn fields.

Thanks for your response.

 

Yup, we have been running straight trucks for a few years. The first thing we did after purchasing them is to widen and pack well all the field driveways. Also after the first load out of the field I have sort of a road build just from the weight of the truck packing the dirt. I always park and drive in the same spot and the grain cart hauls the grain to the trucks. There is only one field I'm worried about. The field approach is up hill. I have a hard time even getting the straight trucks out of that one. We'll just have to park in the field across the road and the grain cart will have to cross the road every time to fill the trucks.

We also have wind towers being built on some of our fields. These have a nice gravel road leading to them that we are allowed to use.

I have a neighbor who's kids have worked for us on the farm. He drove truck for years. He said a good trick it to move the truck forward and back after you park to pack yourself down a hard patch. If it works he says it's best to pack it down like this after the first dump is on the truck and before it's completely loaded. According to him the only time he had trouble leaving the field is when he would pullin and they would dump a lot of weight on him without him getting a chance to pack himself down a spot. Now that I know this I will watch out for that.

Thanks for your reply saying that this truck will work. That makes me relax some. Now all I have to worry about is learning how to drive a tractor trailer. lol. Thankfully, I'll be hauling out of the frozen farm yard and down the road this month. The will help me build experience and confidence before next fall.