15 speed vs. 8LL

Neither. 13 or 18 sp.

 

I agree with Gambi at least a 13. Driving in those fields can be tricky. Ive hauled grain and also sweet corn out of fields with a 10 speed and a 18 speed and by far the 18 was the trick.But thats just my 2 cents.

 

I just don't see where the super low reduction is needed in an ag related application. If a guy has even half a brain he can take off in 1st or 2nd gear at idle with not much problem. No need to be upshifting to 30mph in a cornfield.

I think if you have a hilly drive or a lot of stop 'n go from bin to terminal, you'd appreciate more gears up top, rather than down low.

 

The 18 speed has a low low ratio of 14.40 to one. The 8LL has a low low of 14.56 to one. Thats less than 1% difference and nothing you could ever feel from the drivers seat. The 15 speed has a 13.31 low low. Its actually a faster low than the 8LL or the 18 speed but its still quiet low. The other difference with the 15 speed is its OD gear. The 8LL has a .74 OD, 18 speed .73, While the 15 speed has a .79 OD so your on road cruising RPM Will be slightly higher. As far as the 13 speed low gear is only 12.31 to one. It low but I feel in an off road heavy haul situation like yours it border line to high. Not that it wont work. They are used all the time off road but the extra of the 8LL or 18 speed makes a tough start a little easier on the truck. A 10 speed actually has a lower 1st gear than low in a 13 speed at 12.69 to one.
If you are buying new truck go for the 18 speed. If your looking used I like the 8LL better than the 15 speed but either will work just fine.

 

i had a 15 in my 359 that worked well. i hauled grain from the field and low low was always low enough with 370 rears and tall 24.5 tires also i put 30 or 40 ton on when i did it, which is lil heavy but 425 cat did it at an idle. my new truck has an 18 and i have 2 say that i really like it. but they are more expensive to buy than the 15. either way i think ur on the rite track.

 

I've had experience with both. If I had to pick between the two I'd go with the 15. Had one in a silage truck I drove for several years. I have driven a 8LL in a dump truck and don't care for them on road or off. There where times that the deep reduction on the 15 was'nt slow enough in the fields. Sometimes shifting can be tricky in the field. I guess it's just personal taste. I'd rather have a 13 or 18 but I did'nt mind the 15 for off road work.

 

If i had to choose between a 15spd or 8spd i would take the 8spd. Have one in a tri axel dump and love it for off road and on. Low enough gears for off road and plenty fast enough for the high way with a reasonable rpm. To me a 15spd is a glorified 10spd. I have run quite a few 15spds and never used more than 2 of the deep reduction gears. IMO a 8spd is a better all around on rd and off rd tranny.