Do I NEED heavy specs?

4way lock means just that. You need lockers on both axles plus your interlock to drive all 4 wheels. Now if you only have a locker in the back and your interlock you would only have 3 wheels driving at all times. If you only got a interlock it only drives two wheels at one time.
That's where they get the term 4 way lockup. Makes perfect sence to me. And yes a tridrive if equipped with lockers is called 6 way lockers.
They are referring to the actual wheels doing the driving.
By the way , I don't think I have ever seen a tridrive with out lockers.
The people who order those are mostly concerned with traction then wieght.

 

By the way, I had those exact specs in a kenwoth I had and those were the best all around gears to have. Great in the job site and good cruiser on the big road. Keep in mind that's on tall 24.5s.
Don't worry about the 40s there good rears if you treat them nice, and if one decides to granade they are one of the cheapest to fix.

 

Changing the oil in the transmission and rear gears, and doing plug swaps to get the fine metal particles out is always a good idea.

 

You have it reversed, that would be the same as 3.70 on 22.5 rubber.
Switching from tall to short would be like one gear ratio. Unless you were going from tall24.5 to low pro 22.5 then that would be almost two ratios.
Keep in mind this is all on the same truck.not getting into overdrive ratios yada yada yada.

 

Yes, I understand that this is how the term is used. The point is that this is an incorrect definition of the term "4 way lockers". It is, however, a correct definition for "4 wheel lockers". 4 way lockers as used to describe full lockers on a tandem is just one of those incorrect terms coined by someone that caught on and is used so extensively that people just accept it without thought not unlike the misuse of "RPMs" when the proper term is "RPM". No such thing as "RPMs" but it gets used so prolifically that it becomes accepted as correct. I realize that all this is just semantics but it is just as easy to use terms correctly as it is to use them incorrectly regardless of popular convention.

 

A step in gear ratio is worth about 100 rpm at 65. A switch from 11R to low pro is closer to 50 rpm. Tall 24's to low 22's is about a hundred.

Check http://www.powerspec.cummins.com/site/gearing/gearing.htm

For all your gearing quandaries.

 

Are pretty close there. It does go up, but not sure about to a 4.10. My old FLD came with 11R22.5 and I switched to 22.5LP and it made it a 3.95 ratio. That's what I had to set the speedo at to calibrate it correctly.

 

LOL, it's the opposite way around

 

If he wanted to keep the same engine rpm but go with 22.5s, he would have to go to a 3.70 ratio. That's all I was trying to say.
Maybe I'm just confused as to what he was trying to ask, LoL