Trans Topic

[Duke]

The thing that plagues both of us tranny-wise is that there's a very big jump from tranny torque input from under 660 ftlbs up to over 1050 ftlbs and very little in between.

The Spicer & Fuller type manuals we have are input rated to about 660 ftlbs at the flywheel. If you keep turning up your DT466, you will be in excess of the manufacturers maximum suggested input torque and could grenade your tranny. Most of the single countershaft "smallbox" transmissions like you and I have can't handle much more than 660 ftlbs from our M/D engines.

The allison MT series may be somewhere in between, but you have to ask lots of questions and read the specs before you install. A rebuilt Allison MT series and the conversion to fit your truck would run $8,000 or more, I'd bet. I can't believe you could get a rebuilt one for under $6,000, then you've got all the conversion costs. Might want to just consider trading on another truck.

If you wanted a manual that can hold more power, you have to jump to a twin countershaft transmission, like an 8LL. It can handle the torque output easily, but even the rebuilts are expensive. They're also heavy and require a bell housing change to install.

My situation is further complicated by a PTO change, and possible interference by the front driveshaft.

 

[Markinter]

Your right Duke about getting another truck. I really like my truck and I bought it with the camper on it for 24k with 103k on the motor. It has saved me lots of money because the cost of operation is so low. If I was to spec out another truck it would have air-ride suspension air-cab etc. I'm stuck with what I have and it's not to bad. I think the auto tranny is not a viable option for me. This truck is a work/pleasure vehicle so I need to stike a balance on my mods. Without this and other forums it would be tough to make informed choices.

 

[Duke]

Thought you'd really like this one:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=63741&item=4540636235&rd=1

I know what you mean. It's weird with M/D trucks.....it's so tough to get answers on mods & upgrades. That's why I wanted to get an M/D forum(s) started so bad.

Maybe someday they'll let me take this thing and link it to the oilburners site. Then we can really open the forums up and get some big hitters here to help us.

What would be great would be some big-time sponsors (Alcoa, RoadRanger, etc)

 

[Markinter]

nice truck, the guy probably paid top dollar when it was new. Those hauler bed arent cheap. I'm in Phoenix in a parking lot 2:00am using someones wireless network. I have 1 more quick job tonight and then its back home I go.

 

[Duke]

Well, looks like I'm gonna do it. I'm gonna go with.................(drum roll please)









The Eaton Fuller RTO6613 Road Ranger tranny, not the Spicer 6+1.

I can't believe I'm doing this, but I know this truck deserves more than a straight 5 speed and damn-it, I want to enjoy it more while I'm using it at work, so I'm doing it.
I haven't heard much good about the 6+1, even though it seems like the perfect choice, I just can't get excited about a transmission with a bad reputation. I've heard nothing but good about the RTO6613.

Navistar45 convinced me to go with it, so if I don't like it, it's all his fault

It's scheduled to go in late next week.

 

[nevrenufhp]

Is that when the EDM injectors & twin turbos go in too?

 

[Duke]

I still can't see where twins would fit without a lot of plumbing work. Have you seen anyone set up a DT with twins? Damn that'd be fun.

If I have any play money left, the Schwitzer & extra gauges will be next.

Then I really have to cool it for a while. This tranny is gonna be $$$$$$$. Yikes!

 

[Markinter]

Duke, Congrates on the tranny

Your going to feel like you have a new truck with the new tranny in. You will really feel the difference that uping the fuel makes .

I just go home from working in Vegas and theres a hill (Baker grade) that is a hard climb. I passed a Chevy 6500 towtruck that was carring a minivan while I was towing 9k. I don't know what motor he had in it. He did pass me later on the downhill . Of course the tow guy may have just been takin it easy.Previously and with a lighter trailer 38mph was max up that hill, this time 52 and not pressing too hard .

 

[Duke]

Duke, Congrates on the tranny

Your going to feel like you have a new truck with the new tranny in. You will really feel the difference that uping the fuel makes .

I just go home from working in Vegas and theres a hill (Baker grade) that is a hard climb. I passed a Chevy 6500 towtruck that was carring a minivan while I was towing 9k. I don't know what motor he had in it. He did pass me later on the downhill . Of course the tow guy may have just been takin it easy.Previously and with a lighter trailer 38mph was max up that hill, this time 52 and not pressing too hard .

Thanks, Mark. I just hope everything goes OK. I can't even say with 100% certainty that it will go exactly as planned and that I'll love it once it's in, but it sounds promising. Guess I better not sell the stock 5 speed too quick.

If I had a crystal ball, I think I might do the turbo & new dash cluster guages and that's it for performance mods. (yeah right :Sly )

I live in a much different enviroment than you and my typical driving situations really don't allow for high speed or highway driving. I can honestly say my truck has enough power to be dangerous if you're not careful. I can see where in your situation you'd want plenty of power & roadspeed in those long highway drives you have.

 

[navistar45]

Well, looks like I'm gonna do it. I'm gonna go with.................(drum roll please)









The Eaton Fuller RTO6613 Road Ranger tranny, not the Spicer 6+1.

I can't believe I'm doing this, but I know this truck deserves more than a straight 5 speed and damn-it, I want to enjoy it more while I'm using it at work, so I'm doing it.
I haven't heard much good about the 6+1, even though it seems like the perfect choice, I just can't get excited about a transmission with a bad reputation. I've heard nothing but good about the RTO6613.

Navistar45 convinced me to go with it, so if I don't like it, it's all his fault

It's scheduled to go in late next week.

congrats on your decision duke! i think you will be pleased,BTW i think i will be going outta town on the week of your tranny swap,so dont bother looking for me! lol . are u buying a used tranny,new,used parts truck with a tranny in it? what kind of money are you being quoted??

 

[Duke]

It's a rebuilt RTO6613.

 

[dozer]

My impression of the Roadrangers (at least the older ones), is that they'll handle far more torque than the 'rating'. There are a whole lotta semi-tractors running around with engines putting out more torque than the old RR910's, 1310's, etc. were rated for; and they do fine.

In fact, for your app, an RT910 or RTO910 would be a nice tranny.

I have an RT910, but I've been told that no extra parts are needed to make an overdrive version from it. I guess you just have to swap a pair of gears around inside.

Anyway, if that 6613 is built at all like the older ones, it oughta handle all the torque your 466 can put out.

Richard

 

[Duke]

A 910 would be rated for 900ftlbs. A 1310 would be rated for 1300.
The RTO6613 would be rated for 660 ftlbs.

I know a guy with a 250HP 8.3L Cummins. He has an RT6613 (same tranny, no overdrive).

I looked at the bigger RT's. The problem is the RT910,1011,1110, etc, have twin countershafts in them to split the higher torque loads. That makes them very wide, not leaving enough room for my front driveshaft to slide by.

Others have said the same thing as you, basically the older the tranny, the tougher it was.

 

[dozer]

yup, exactly. 910 is 900 ft-lbs. That's why I suggested it. And they're around pretty cheap. I'm seeing leftover re-cons being offered for under a grand.


yah...that driveshaft would be an issue....forgot about that.

funny how they do the 4x4's in M/D's. not real swift most of the time.

I just looked at an 80's mil-surplus GMC7000 4x4 for my next crane-truck.

But the @#$#@$ idjits mounted the t-case so that about 3" of it sticks up ABOVE the frame-rails! ***...???

So I can't mount my knuckleboom behind the cab unless I move it ANOTHER 18" back. Really stupid driveline layout...

Plus it had to have 7" blocks under the front-springs just so the pumpkin would clear the oil-pan. If they'd make that axle with just two more inches of offset....just two!

ah well... I'm too poor to drive a truck with 6.31 axles anyway...

 

[Duke]

Dozer,

Yeah, the GMC 4x4's are just ridiculous nose-high lookin things. One thing I kinda like about my IH, it isn't overly high in the nose.

I was looking at commercial truck parts on Ebay. I noticed an ad for a Fuller 10 speed. I noticed right below that a parts truck, a '83 S-1700 4x4 from the same seller as the Fuller 10 speed. The ad for the 10 speed Fuller said it came from the S-1700 4x4. That Fuller tranny looked really big, like a twin countershaft tranny.

What does all this mean?

I think it means a twin countershaft tranny just might fit afterall!

If that's the case, I need to decide on some possible Eaton/Fuller models to try in my truck. I have no problem with the RTO 6613, but if I can go with an even tougher tranny, I should do so. If the Fuller 10 speed fits, then so should a Fuller 10 speed with O/D.

Maybe I'll get lucky?