Tractor First, Right?

It's an ok transmission. Not much for top end. 65 mph it's 1600 rpm with 321 rears and tall 24.5 rubber

 

I put it in low for backing up. Reverse is very fast

 

The 918B series has a lower low hole than a 15 deep along with half gears

 

15 speed is really an 11 speed. Lo-lo is the slowest ratio then 2,3,4,5 overlap 6,7,8,9. In other words you can shift from 1,6,7,8,9,10,11,12,13,14,15. Or 1,2,3,4,5,9,10,11,12,13,14,15.....Or....Well you get the idea.

 

Are you sure about that? While it's been several years since i ran one i would of sworn that the bottom side was different gears than the middle. Tho 5th and 6th were either very close or the same gear.

 

Positive. At least on the two I've shifted. I've shifted two 15's......a 1996 15 direct and a 1986 15 single over. All the deep reduction gears overlap low range except deep reduction first. Want to see a super trucker job applicant get flustered take him for a test drive in a 15 and watch him try to make the 5-6 shift lol.

 

The two I've had...one was in a 77 k100 bolted to 12v92. And the other in my 91 pete booked to a 3406b. Also another in my dad's 93 w9 with that goofy b model c configuration peek engine. All 3 had the double over drive where the top 2 are reversed in the shift pattern. Was yours like that?

He means the lowest gear 'first' or granny gear or low gear whatever you want to call it, is geared even lower. The lower the gearing the easier it is to get a load in motion.