18 Speed Splits

All cummins big cams at the moment, my w900a and dads Classic XL are the only two cat powered trucks we have.

His aerodyne may see a repower though, just not sure what at this time.

 

T

thats what I was thinking

 

EACH GEAR HAS A LOW AND A HIGH, so in THEORY Even REVERSE has a LOW and a HIGH on Both Sides of the Split.
4 Reverse Gears Total. GO Figure.

 

The pocket gear in the 9, 13 and 18 speeds is of no benefit to use. The ratios are almost identical to ratios already in the regular shift pattern.

Eaton encourages drivers not to use those gears because they have a high rate of reduction in the primary box and therefor weaker then the other comparable gears in the regular shift pattern. The lower gear reduction the weaker the gear is. The more gear teeth in contact with each other the stronger the gear.

Their is no sense in using the weaker gear train if the same overall ratio can be achieved with a stronger gear set.

 

I've have several million mile plus trucks and have always used that gear in high range. Perfect for in town corners on a car carrier with 3.08 rears. My failures have always been input or output bearings. After 800k if we do a clutch the tranny is swapped with an Eaton reman. Tried two weller reman and didn't last 200k. Junk.

 

I always wondered about that, if it was safe. You can actually modify the red splitter on a 13 and get the same result.

 

Ive tried this gear change a few times and whilst it seems to work it even 'sounds' like it putting things under strain. I dont think it would be a gear change id like to get wrong.... I feel a lot more comfortable dropping to bottom box.

 

There's a whole thread on this somewhere around here. There are some minor internal differences and Eaton puts the split lockout on the 13's for a reason.