RTLO 14613B Oddity

Bizarre! I don't see how it could be .73 instead of .85.

 

How are you coming up with your information as far as rpm and final ratio
You are correct to my knowledge that the b ratio is approximately.85 and the a is approximately.73
What rear end ratio because high numerical ratios will make the gears seem closer together.
when you say it doesn’t 13 very well are you saying it doesn’t shift properly or that it isn’t very noticeable?

 

I don't know how it was done, but I recall guys swapping gears or something inside the box to make it a "double over". I wonder if that is what happened.

 

If they switched gears 7/8 in the trans.to try to get Double overdrive it would have a U shift pattern. Unless they also put a RTX shift rail top on it.
I just put a RTOO-14613 in my truck last week, It has the RTX top which gives it a standard shift pattern.

 

If 8 Lo feels like direct 1 to 1 and 8 Hi feels like .74. Then it may have been switched out from .86 to .74 OD gear.. Because it had a .86 before the lower gear will be closer together. The 1 to 1 and then step to .74 is a big step on the top end. That's what the 10 speed I took out had.

 

Those older Freightliner gearboxes can get strange when you mix models. It’s running like a ...Frankenstein setup, drives like a 10-speed but is really meant to be a 13.

The 50 rpm gap in the high gears isn’t ideal, but as long as it shifts cleanly and doesn’t chatter under load, you can treat it like an odd 10-speed and get used to how it pulls.

 

That 1400 ft/lb trans really isn’t strong enough for that truck. Running it like that could fail under load and that’s dangerous on the road. Swapping to an 18913A or 18918B will handle the torque safely and keep you out of trouble.