So I finally bought a little single axle dump truck. Found one that fit my wants pretty close. Only thing I didn't get was a powerhouse of an engine. Its a Ford F-800 with a 5.9 Cummins and an Eaton 9 speed. I know the 5.9 is really small for a truck this size. Read all about it online before I purchased it so it wasn't a surprise, but I started reading how some 9 speeds are set up to be converted to a 13 speed with just a inexpensive kit. 99% sure mine isn't one BUT it got me thinking - could I get the splitter box for my 9 and make it a 13? I don't wish to get taller top gears like some over the road guys, that little Cummins just doesn't have the brawn, but could I have it so I could split my top 4 gears just for tighter spacing? Not only would it be cool as hell to have a 13, it would probably make the engine a little happier. Has anyone done this before?
Well, first, get the numbers off of your transmission's tag.
Its an RT6609A
That 5.9 can make gobs of reliable horsepower too with a little work.
IIRC it is only the 1650 and 1850 lbs-ft torque trans that can be converted to 13 speed. The 6609 is a 600 lbs-ft unit so be careful if you goose the 5.9.
No, the RT6613 does not split gears on the high side. It's a deep reduction gear box.
I used to have a dodge one ton with a Cummins 5.9 that someone before me had done some work to for more power. It was nice to drive. I want to be careful doing that to this truck as I worry I’ll damage something since the engine has so much more load on it. More research is needed. I’ve only driven a few 13 speeds in my time and I am 99% sure those you could only split the upper range as I remember usually I could just shift it like a 9 and then when I was on top gear just pop it into high range. Those trucks had a lot of power though. If this 13 wouldn’t allow me to split the top end it wouldn’t be as good for me.
http://www.roadranger.com/rr/ProductsServices/ProductsbyCategory/Transmissions/PCT_486870
Ok that’s really interesting. Thanks for posting that. If I am reading it correctly it looks like the RT6613 does split the top range but overall has a MUCH deeper reduction.
Ok. So I am reading it wrong. That helps considerably. Is this a rare transmission? I am somewhat surprised they make a 13 with the 660ftlbs of torque limit. What would a practical use for these super low gears be in a truck making so little power? If it was so heavy you needed those to get it rolling I doubt it would be very drivable at road speed?
International used the 6613 in on/off road-Ag, construction you name it with the DT466 for power. You will notice there is also the RTO 6613 with an overdrive. The RT6613 was direct .100 in top gear. The RTO6613 was .80 in top gear. And any of the B class trucks are not real speed demons. But the Factory torque rating on gear boxes has always been under rated. Back 50 years ago the only 13speed offered was the RT/RTO 9513-the Howler Monkey of the highways. Those gear boxes were factory installed behind A model 400 Cats, 1693 Cat, 380 NTC Cummins, and 430hp 12V71 Detroits. The RTO12513 was installed factory behind Cat 3408's, KTA 600's and 475 hp Silver 92 Detroits. I wouldn't worry about a 5.9 in-front of a 6613. 5.9 is a good engine but not that good.
I have a rt613 in a 80,000 lbs crane behind a 6-71 detroit. I had one in a smaller 50,000lbs crane also, behind a 3208 and later a 8.3 cummins. The super low gears are for moving a heavy load without a lot of power. I really like the tight gear spacing in a 613-6613, for a heavy load. I guess I don't see any reason for the 13 instead of the 9 in a small single axle dump. You aren't going to have enough truck for the transmission. If you really want a 13, I would just swap transmission and cut the driveline down. How much are you going to be hauling? More than likely you're going to be around 20-25,000 gross or less, I think you're wasting money wanting a 13, but its your $$ not mine.
I think you need a od axillary box of my mind just works different
Yeah definitely no need for a 13. I just thought maybe it was a reasonable option to get a little smoother acceleration once you get past 4th gear. It would also be cool as hell. I have a thing for trucks that are long in the gears. One of my deal breakers when searching for a single axle dump was an automatic or a 6 speed. Dunno why. Just like the feel of running through the gears. Its a dying pastime...
I got tired of row boats years ago. I skip gears in my Toyota Tacoma all the time.
My old man always used to say "there's a time & place for every gear in the box, but you don't have to use all of them all the time"........ I skip gears in my personal car, let alone my work pickup.
Sometimes it's even better to let someone else drive, then you can set back relax and harass them for their ****** driving skills for entertainment.
Heck, a single axle dump truck, you're limited in weight you can put on it anyway, I'd prefer a 10 speed in that application over a 13 speed, unless you need the deep reduction you can get with a 13 speed. Of course all of this has to do with the gear in the rear end. If it's geared to do 90 mph down the highway, well, there's your problem.
It's another dump truck thread.
It most certainly is not. I think I would be turning 4k on that little Cummins to get 90 out of her.
Got a chuckle out of this one. I hadn't heard that before.