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Discussion Starter #1 (Edited)
First,
For basic questions, if you want to learn more about any one model transmission or to find service, parts, and operators manuals for for most all Eaton, Fuller, and Roadranger transmissions as well as driveshafts, clutches and so much more please try the Roadranger Literature Center
It's a great place to start!

EDIT
These first three post show how a transfer case may be mounted to a Roadranger, they were copied from another thread, thus why they appear out of order...



Just this weekend I saw one with a bolt on transfer case in a 1 ton Chevy truck.

I am pretty familiar with the small 10 speed Roadrangers, model RT610, RT6610, and the RTO versions, and there is not a factory way to bolt on a transfer case that I know of. The adapter I saw this weekend was shop made, but simple and seemed very well thought out. Until yesterday I would have said you can't do it.. but I did not have a reason to try it either.

Grigg
 

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Discussion Starter #3
Any chance you could get a pic or two of that setup?
Sure, I took some Saturday, but it is very hard to see with the cross member in the way. I got a better picture of it in my mind by listening to the description than what I could actually see when I crawled under the truck...

The adapter was made of two pieces of plate steel, one to act as the new rear cover for the Roadranger, one to be the round flange the transfer case bolts to. They are connected by a piece of pipe/tube and some braces welded in to stiffen things. The pipe is bored to accept and locate off of the output shaft rear bearing that protrudes part way out of the case, otherwise the back of the case is flat.

The coupling was a splined sleeve to fit the 2.5" 10 spline (I think) on the Roadranger output, and whatever was needed for the transfer case on the other side. The two halves were machined to press fit together and then welded.

The Roadranger relies on the output shaft nut to keep the bearings snug on the shaft, so a snap ring grove was machined in the output shaft, a color with six 1/4-20 set screws in the face of it was slid on the shaft, the snap ring installed, and the set screws tightened and with some lock-tite.

This is the truck


Transfer case


Transmission


And a really poor picture of where the adapter should be


Grigg
 

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This post is primarily being posted for Chansey and Grigg to see.

I've decided to steer clear of the New Venture trashmissions and and stick with Eaton. Chansey is using an Eaton Fuller FSO8406 type and Grigg is using a RR 10 speed.

SOOO my question is this: Which, if either is synchro'd? I really don't want to have to double clutch this baby all the time.

I like the Fuller 6 speed, but the extra low gears and slightly higher OD in the RR 10 speed is tempting. But, is it Synchro'd in the 10 speeds? I was looking specifically at the FRO11210C. It seems to be cheaply available.

One concern I've had, even with the FSO8406 is over loading it. I plan to have my 6BT up around 500 hp and hopefully 1100 lb-ft of torque. I think that's too much for even the 6 speed fuller. But, the FRO11210C is rated for 1150....... FINALLY, a tranny I won't kill!

Looking for feedback on this...... Thanks in advance.
 

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Discussion Starter #5
The FSO-6406 and 8406 are synchronized transmissions, they would be most folks first choice between that and a 10 speed.

As far as strength, if an NV4500 will almost stand up to that much power, either the 6 or 10 speed should be fine. If you take care and don't abuse them I doubt you have any problems. The book says both the 6 and the small 10 speed weighs approx 350 lb dry with no clutch housing, and are designed for approx 660 lb ft or torque.

I may be mistaken, but aren't the FRO transmissions of European design? If so I hear they are expensive to work on, not very desirable transmissions for long term use.

If you look at a regular Roadranger that is designed for 1,100 lb ft or torque, a 10 speed weighs 650 lb dry, and is quite wide. that's a whole lot of transmission, and probably not necessary even behind a strong 6BT?
If you are planning to put this in a 47-53 Chevy then the RTO-610 or RTO-6610 is about as wide as you want. Check out my pictures, it's tight..

The 10 speed Roadrangers are not synchronized (well, the range shift is, but that's it). Even so they are not hard to drive once you get a few weeks practice. You are not supposed to drive without the clutch, but it is quite easy, and very fast.

I would recommend the RTO6610 for a towing truck, lots of gears to keep you moving on the hills, and a reasonably low first gear to get you going, with an overdrive for mileage. Also consider the older RTO610, and depending on your gears the RT versions as well (no OD). If you don't need overdrive then the newer RT6609A may work too, it has a good low gear.
The small 10 speeds can be converted to OD with $400-$600 depending on the model, I have the part numbers if interested.

As a second and third choice respectively the RTO8406A and RTO6406A transmissions sound pretty nice. They are on my list of transmissions to buy if the price is right...

Grigg
 

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I have no idea on the FR series transmissions design or otherwise..... All I know is I found them relatively cheap in heavytruckparts.net and they sounded pretty cool on Roadranger's website.

So, you guys think that the 8406 will hold up to 1000+ lb ft of torque without breaking? I just figure if I went commercial, I'd go with something rated for the power I'm building. but, I assume there's really a large margin for error plus the fact that one really doesn't develop full power very often. I may just go with the six speed since it's synchro'd......

Grigg, exactly how does this clutchless deal work anyway? I'm pretty sure I know how it works on upshifts, (Put foot into throttle, let off and yank into the next gear at the same time.) but on downshifts it has me baffled. Plus, I would think that doing that woud severely affect tranny life....
 

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Discussion Starter #7 (Edited)
Grigg, exactly how does this clutchless deal work anyway? I'm pretty sure I know how it works on upshifts, (Put foot into throttle, let off and yank into the next gear at the same time.) but on downshifts it has me baffled. Plus, I would think that doing that would severely affect tranny life....
Obviously you need the clutch to get started from a stop..
It's just double clutching/matching speeds like you have to do any how even if you used the clutch. The transmission is non synchronized, clutch or not the speed matching is the same.

If you don't use the clutch, instead you work the throttle till the engine is neither pulling nor holding back, at that second you slip the stick into neutral (no clutch). Then work the throttle to match the engine RPM for the road speed and the gear you want (either up or down shifting same as with the clutch) then slip the stick into the right gear (but with no clutch) and continue driving as normal.

The Roadranger manuals don't want you to do it, and if you get it wrong you "grind gears". If you are heavily loaded it's best to use the clutch, less chance of screwing something up if you manage to stick it in the wrong gear. The Roadranger transmissions are quite tough. The gears are all always in mesh, you only slide small sliding clutches that lock one gear to a shaft at a time.

The proper way is explained Here in the 6610 manual pages 5 and 6.

Grigg
 

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Ok, so you double clutch, but never clutch. :)

Hmm. Maybe that 6 speed would be just as well..... Synchro's are kinda nice.... :)

Oh boy... Decisions, decisions.......
 

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I like not having to clutch....never drove anything with more than 5 speeds though!
 

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Fuller transmissions

Allthoe the FS series are listed as Syncronized you still need to speed match them weather you use the clutch or not. The RT transmissions are twin countershaft split transmissions. The front part has 5 gears and the rear has 2 or 3 depending if its a 9,10,13,15 or 18 speed. The FR is basically the same as the RT with some updates. The shifter mecchanism is different and the input shaft gear is thicker so the sun gear is different too.

The RTs are easyer to shift and can be shifted much faster ten the FRs. On Fuller transmissions the first number tells you how strong the transmission is (such as a 15000 series), the last one is the gears (such as 15 for a 15 speed).

Not using the clutch does not damage the transmmision, crashing gears does. Using the clutch to shift causes premature wear and results in less smooth shifts. Preselecting (meaning splitting the auxiliary with the main sill in gear) as instructed by Fuller causes damage to the auxiliary, only split with the main in neutral. Besides there is a lock out bar wich blocks the shift when the main is in gear.
 

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That is some interesting info. I'm glad to hear it. Looks like if I go 10 speed, it's an RT series for me......

So, even though the 6 speeds are synchro'd, you still have to double clutch? What's the point in that??
 

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Fuller transmissions

You can double clutch or slip shift any of them. I would go with a FS transmission because the twin countershaft transmissuons are huge and much more expensive. Spicer, ZF, Rockwell, Mack and others make equivalent transmissions but Fuller is more common and usually easyer to shift.

The older transmissions are less touchy and easyer to shift, I would put the cut off year at 2000. Get a transmission with a pull type clutch (6000-8000 series) and take a good look at the input shaft. Replace the cross shat bushings and fork (easy to do) and check the cross shafts.

There are all sorts of bell and shifter options. One to avoid is the GMC medium duty cable set up wich is convoluted and binds.

As for double clutching it does absolutely nothing to help you getting it in gear. If you drive a truck with an FS transmission you will find out that its not syncronized like a car. You must speed speed match it and its better if you shift without the clutch.
 

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Back in my working days we had a Ford 600 series with a 20 foot flatbed. It had a synchronized 6 speed non overdrive Fuller. It shifted no differently than any other synchronized 5 speed truck transmission that I had ever driven. No you couldn't out run the synchronizers because they operated just a tad bit slower than those in a car transmission but I never had to match the engine speed to the transmission speed to change gears. That to me would indicate another issue going on such as a clutch issue or maybe a gear oil mismatch.
 

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Fuller FS

I am speaking from a lifetime of working on and driving trucks. Only two i can think of shifted allmost like a pick-up. Older Clark transmissions shift pretty easy.

To shift properly Fuller FS and Spicer ES the need to be speed matched. It is true the if you use 90W instead of 50W they get very sticky but thats a separate issue. If you don't disengage the clutch to shift its irrelevant weather it disengages properly. If the clutch sticks its usually because the input shaft is grooved but this is more common with the RT models.

In my experience working with fleets I saw tremendous damage by impatient drivers not speed matching such as broken Syncronizers and broken shift forks. Then coupled with drivers using the clutch to shift or using too high a gear I've seen drivetrain explosions and all sorts of other severe damage.

Wile you can do ok shifting with the clutch its much smoother to shift without. To give you an example we bought a International 9400 with a 370 HP Cummins M11 and a ZF 10 speed. The truck had 700.000 miles and the original clutch not even half worn and shifted like new.

If you expect this transmission to shift like a car you will destroy it, I've had to fix way too many. I would classify the FS as semi syncronized wich is a big part of the reason why the non syncronized RTs can be shifted faster. As they have to be, crossing an intersection I would have to shift three gears on my Freightliner with a 460 hp N14 Cummins and a RTLO 15 speed. By the way if you want an RT 18 speed Roadranger is my first choice.
 

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This is all encouraging information..... Does anybody know what the difference is between the RTO-610 and RTO-6610 tranny's?
 

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Discussion Starter #16 (Edited)
Does anybody know what the difference is between the RTO-610 and RTO-6610 tranny's?
The 6610 is a later version, it has finer pitch gear teeth and therefor is slightly stronger, and a little quieter. Rated at 660lbft instead of 600lbft of torque.
You can externally spot a 6610 over a 610 by the location of the air filter regulator unit, although not entirely reliable. The 610 has a bracket on the left side at the back of the main case with the filter and regulator. The 6610 has a newer combined filter regulator unit bolted to the range air cylinder cap, on the back top right corner of the transmission.

It's also easy to pull the shifter off and take a look at the gears.

I have two RT-610's, an RT-6610, and an RTO-610, I'll try to dig up some pictures of them.

You can download both the service and parts manuals for them from the Eaton/Fuller/Roadranger website.

To distinguish a 6609, 610, 6610, 613, or 6613 from the larger Roadrangers look for two things.
1, The slave valve will be on the right side, the vast majority of larger transmissions have it on the left side.
2, They were/are only available with cast iron clutch housings, so far as I can tell. So if you see a Roadranger with an aluminum clutch housing it's almost certainly a larger model.

Grigg
 

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Discussion Starter #17 (Edited)
You can externally spot a 6610 over a 610 by the location of the air filter regulator unit, although not entirely reliable. The 610 has a bracket on the left side at the back of the main case with the filter and regulator. The 6610 has a newer combined filter regulator unit bolted to the range air cylinder cap, on the back top right corner of the transmission.
Picture of an RT-610 with the filter regulator mounted on the left side

Note the filter and the regulator are separate units connected with a pipe nipple. (an RT-510, even older, will have a filter that looks similar to a fuel oil filter for a furnace, and in the same location)

This is an RT0-6610 on the left, note the combined filter regulator is mounted on the very back of the transmission.

On the right is the RT-610 same as the first picture.

Again, spotting the different locations will only give you an idea, as you can easily swap the new style range cylinder cap and filter regulator unit to an older model, I even have one that someone has swapped/updated.

Grigg
 

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So the RT series aren't rated at any more torque than the FS series fullers? Crud...... Oh well, It's probably one of those deals where it's so over-built it wont matter anyway...

So, if the price is right, a 610 is still a good buy, just a little noisier (though, with dual straight-piped stacks, I doubt I'll notice. ;) ) and 60 lbft less torque. (woopy-ding....)
 

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Discussion Starter #20
The torque on any of the Eaton, fuller, or Roadrangers is the first one or two numbers of the model number X 100 or 10 respectively. So model 610 is 600 lb ft of torque, and 10 speeds. Model 6610 is 660 lb ft and 10 speeds.

They only made air shift for the range, never electric.
One truck I had used a very small electric compressor and an air tank about half the size of a shoe box. Once I fixed the leaks the compressor rarely cycled, it does not take much air to shift. Heard of a guy using the air from a spare tire to shift for a week, which I don't think is much of a stretch.

Grigg
 
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