18 spd vs 15spd/9LL

81 according to the line sheet anyway. I've never had the need to run it out to 80 MPH to see.

But I'm at 1600 RPM at 60 MPH.

 

Whats the model number on that 18? Sounds interesting. I guess DBL Over drive is a simple matter of having those last to gear ratios to be less than 1.00 : 1.
And I see a bunch of those in the 18 speed ratio chart.
www.roadranger.com/rr/ProductsServices/ProductsbyCategory/Transmissions/PCT_486870

 

No such thing as too many gears right?

 

Especially with less power! And just because you have 18 or 15 doesn't mean you have to use them all every time all day long. Use them if you need them.

The 379 Pete in my avatar had an Eaton Fuller RTO 16210C which is a 10 speed. It was low geared enough on bottom that on flat ground I could take off with 40,000 lbs in 3rd gear easy. 3rd was slightly lower than 1st in my dump trucks 8LL tranny at 6.24.

It had a 13.75 Reverse, 12.69 1st, 9.29 2nd, 6.75 3rd but 10th had some good over drive at .74 it would haul buggy. It was hard not to get a ticket.

I missed a down shift one time on a ridiculous steep grade and had to stop and start all over going up hill with a 62,000 lb backhoe on board and with its low 1st it wasn't an issue. I was attempting to drop 2 gears at once when the grade got steep and the truck slowed down too fast. I should have downshifted earlier and keep the same gear all the way which is what I did the following times I had to travel that mini mountain route.

 

@Art Vandelay he's not talking about typical 5 axle configurations on highways. He runs off highway, crawl up the face of a mountain with a 988 loader on the lowbed type of trucking. You can be as careful as possible and still twist things apart. Few years ago I was in a KW dealer and they had an 18 speed out of a logging truck sitting on the shop floor. Hole the size of your fist through the side of the housing.

Off road trucking in BC is brutal on trucks. Most guys will buy new with as much warranty as possible and then dump them in 4-6 years before they need brakes and clutches.

 

Say what you will but I've seem more 18s in the shop then 15s.......

 

@AModelCat @swaan he doesn't want to hear it, but thanks for trying. Some guys read a brochure and they are instantly experts. The brochures for the 18 make it sound like it is the only good choice...some buy into the glossy pages, instead of decades of real life experience. 18 speed is a fine transmission, but when chained up, spinning, on a #### steep hill, loaded to the nuts, it shock loads the entire drive train violently time and time again, the 15 just handles it better than any 18 can. The guys who are doing tough jobs break 18 speeds all the time, they often swap in a 15 when it grenades.
If i was only pulling 100k lbs, on pavement, and all hills were less than 10% grade, and not buried in mud holes or ice roads with 20 inches of snow on top of it, I would likely prefer an 18 to. The difference between what I do and most do is night and day different. Shiny brochures sell stuff...real world is a lot different.

 

The only difference in high torque transmissions is the gears are zinc coated. Something I read somewhere on a post. All gears are made from same steel.

 

Aren't there some heavier duty 18's though like mentioned the

229128?
If these are tearing up I'd think its because it has a spliter and driver error.

Anytime you see a hole in the side of the transmission the driver put way more strain on the transmission than was necessary in my humble opinion.
I have hauled heavy equipment grossing 100,000 lbs all my life and have never broke a transmission to where it didn't get me back home.

One time the cone on the back side of our 13 Speed lowboy tractor set me back a day and I had to get a ride. But that thing went out running empty back home.
I can't even call the name of that part right now.

If you choose any of those 15 speed transmissions that have any over drive at all you might as well have the bullet proof RTO16210C 10 speed that we ran in our lowboy for 20 years.

It had 13.75 reverse, 12.69 1st and .74 OD

 

Eaton still can't build a automatic trans that is not retarded.
But a manual they made good ones.

 

Just the words "automatic transmission" is retarded. You know how many times I've seen a decent w9 or 379 that actually has a decent price, and then you start looking at the details and it say auto trans and you just go "o poor thing it's retarded."