3.31 gears at 40,000 lbs gross.

4x4ord wrote:

dodge guy wrote:
Ok let’s make this simple once and for all, if gearing does not matter, then the engineers at any manuf. would not have different ratios for towing higher weights. But to tow an XXXX lb trailer you need the next lower gear, and so on. It can’t be made any simpler than that. If you don’t understand that then all you are doing is arguing just to argue!

It is true that for heavier trailers shorter gears are offered. The problem is that some mistake that fact to reason that shorter gears are better for towing than taller gears. 4.30s are offered for towing over 30,000 lbs. 4.30s are a terrible choice for towing 16000 lbs, especially when the truck is used for a daily driver. Peoples’ thinking needs to change to appropriate what is being offered with these new 10 speed transmissions.

You do realize you are saying this in a thread titled "3.31 gears at 40,000 lbs gross". Our comments are meant toward a tall axle towing this kind of weight.

4x4ord wrote:

ShinerBock wrote:


All I did was make a general comment that taller gears put more stress on the trans than shorter gears and some got triggered by it as if I was personally insulting their truck or truck brand.

This is not true. This isn’t about me feeling hurt or insulted. You used unsound reasoning that I wanted to point out to you and others. You stated something to the effect that because you see all these tall geared trucks with grenaded overdrive gears you order nothing but short gears in your fleet especially for towing heavy. I simply wanted to point out that with the 10 r140 if saving your overdrive clutches from grenading while towing is the goal then taller gears are better suited.

This was my first post in this thread....

"Your 3.31 in 8th is very similar to my 3.42 in 5th which I find more pleasant to tow with when towing anything over 10k and has a lot of wind drag. Not only does it keep the EGT's much lower, but it is also better for the trans clutches. Tall rear-end gears plus heavyweight put a lot of strain on the trans clutches, especially in the higher gears."

And you were triggered enough by it to respond and even try to a jab in a few comment later saying that I may be having issues with my truck. My comment about seeing burnt overdrive clutches and grenaded hubs from mainly taller geared trucks did not come from several comments into our discussion after you were triggered by my initial statement.

dodge guy wrote:
Ok let’s make this simple once and for all, if gearing does not matter, then the engineers at any manuf. would not have different ratios for towing higher weights. But to tow an XXXX lb trailer you need the next lower gear, and so on. It can’t be made any simpler than that. If you don’t understand that then all you are doing is arguing just to argue!

It is true that for heavier trailers shorter gears are offered. The problem is that some mistake that fact to reason that shorter gears are better for towing than taller gears. 4.30s are offered for towing over 30,000 lbs. 4.30s are a terrible choice for towing 16000 lbs, especially when the truck is used for a daily driver. Peoples’ thinking needs to change to appropriate what is being offered with these new 10 speed transmissions.

ShinerBock wrote:


All I did was make a general comment that taller gears put more stress on the trans than shorter gears and some got triggered by it as if I was personally insulting their truck or truck brand.

This is not true. This isn’t about me feeling hurt or insulted. You used unsound reasoning that I wanted to point out to you and others. You stated something to the effect that because you see all these tall geared trucks with grenaded overdrive gears you order nothing but short gears in your fleet especially for towing heavy. I simply wanted to point out that with the 10 r140 if saving your overdrive clutches from grenading while towing is the goal then taller gears are better suited.

Ok let’s make this simple once and for all, if gearing does not matter, then the engineers at any manuf. would not have different ratios for towing higher weights. But to tow an XXXX lb trailer you need the next lower gear, and so on. It can’t be made any simpler than that. If you don’t understand that then all you are doing is arguing just to argue!

^^^^Part of the problem with this discussion is in the terminology being used and how it is understood. For instance you use the term “stress” and I believe you’re thinking stress and wear are synonymous. I believe you’re thinking like this:

1.Taller gears increases the stress on the driveline components
2. Increasing stress increases wear
3. Therefore taller gears increase wear on the driveline components.

Furthermore, not only do I believe you’re thinking like this, but, I also believe you think this reasoning is so obviously sound that you can assume we should all understand how you’re thinking without any explanation.

Can you spot the problem with this reasoning as far as how it relates to our discussion on transmitting power through a driveline? I’m challenging you to think about this to help you and others who might be reasoning like this to come to a clearer understanding of things.... I’m not simply wanting to argue.

Devo the dog wrote:

Grit dog wrote:
I'm gettin confused....now I need a show of hands...
Whos team 4x and whos team Shiner?
Lets go boys!

One side argues with noise and the other side argues with more noise. If I was their teacher, I'd walk out of the classroom mumbling "sophomores."

Well then by all means teach us "sophemores" which is correct. Does a taller gear ratio add more stress to the driveline?

Grit dog wrote:
I'm gettin confused....now I need a show of hands...
Whos team 4x and whos team Shiner?
Lets go boys!

One side argues with noise and the other side argues with more noise. If I was their teacher, I'd walk out of the classroom mumbling "sophomores."

Also note...I have 2.73 gears, and 550lb-ft of torque in my Cadillac. Over 80K on the TH-200-4R.

blt2ski wrote:
Roy
I believe you are correct for class 8s. I have not looked into the heavier setups in awhile to see how they are doing things.
I do generally speaking like my direct drive Spicer 7 SP in Navistar. I do wish I had an OD, or 3.42 gears and a lower yet 1st than the 10.08 I have. That so when empty, I can cut rpm's down to 1809-2000 vs the 2400 or so I go at 60. But with a 175/385 non turbo diesel, I need to turn a high amount of R's to motor at 60 at any major gvwr above 18-20k even on a level.

I would agree, unless one take trans, and tire diameter into the equation, rpm peak torque, HP needed, actual best axel ratio is a **** shoot!

Marty

Most of the tractors at work have 13-15L engines, 3.50 gears, and OD in high gear-65MPH is 1400RPM. Three have Cummins L9s, double-OD Allisons with 5.38(!) gears...and the transmissions start in second gear. They are geared WAY too low (1900RPM at 65), and would be much better with 4.56 gears.