Engine/Transmission (1994 - 1998) transmission conv. 4500 to eaton 7 spd (kind of long)

[onestackdram]

Ok guys I have been mulling this over for a while and for what I want to accomplish the 6 spd just isnt what I need. So I got to thinking that if the phurd 750 can run a CTD 5. 9 with a Eaton 7 spd behind it why couldnt I? It would fit my idea for my truck. I like towing and when my sled truck (not listed below) is finished I want to use my 97 to tow it. I therefore dont want to lose my 4:10's but I also do ALOT of driving empty. And since we all know that the only difference between the 4500 and 5600 is a gear added between 3rd and 4th on the 4500, (yes i know the final drive is ALMOST taller in the 5600) it just isnt enough to accomplish my goal.



So to my question. Does anyone have any ideas on where to begin my search for making such a conversion. Or has someone else MUCH WISER than I contimplated this already and found it to be impossible.



The things I can think of right off the top of my head that I need to look into are:



1. Where to buy an eaton that is set up for the cummins 5. 9 application.



2. Where to get the obvious parts that will have to be changed, i. e. bell housing, flywheel etc.



3. Where to get a clutch, pressure plate, so on and so on that will handle anywhere between 400- 450 hp.



4. How to go about mating a drive shaft from the output shaft on the transmission to the input shaft (yolk) to the Dana 80



5. Will a body lift be neccessary to fit this monster under there?



6. How much futher back am I going to have to move the hole in the floor pan of the cab. (not so much a problem as I have bucket seats and custom console (not so custom came out of my old '92. )



7. Cost comparison between going with this or breaking down and going to OKC and dropping 3k + on the 5600 and then almost another 3k for an overdrive unit. The install will be done by me, so I dont need labor cost.



8. And anything else that the "ALL KNOWING OF TDR" can think of or advise on



TIA



Russell

 

[HoleshotHolset]

What is the OD ratio of the Eaton 7 speed?



My only concern would be how you would keep a clutch in it.....



Unless one of our vendors would be nice enough to custom make a good clutch to use with the Eaton..... I tend to think that you could slip/burn out whatever Eaton makes in no time.



When the Eaton breaks - are parts for it reasonably priced and readily available?



How are you going to hook up the speedometer?



Just a few things I thought about as I read your post... .



Matt

 

[JoshPeters]

I've kinda thought about the same thing. I would think that there would be a clutch available somewhere due to how widely that 7spd is used. I was kinda having the same thoughts with my truck. A friend of mine has seen it done. I think he said he saw it at Muncie. I can ask him again. Let me know how it goes. If it goes smooth I may do it myself!





Josh

 

[onestackdram]

Matt, I have no idea what the OD ratio is in the 7 spd. I am trying to find a eaton dealer or even get ahold of the manf. to ask such questions. As far as the speedometer I am going to make a GUESS that it wouldnt be too much different than doing the CTD conv into a ford. I would think that most of the components like the speedometer hook ups dont change much between the 550 to the 750. But I could be WAY off. Nevertheless I am convinced that something like that can be dealt with. As far as the parts issue I dont worry about that much we have a distributor here in Salina that keeps Eaton parts in stock, and also can get ahold of them I have yet to talk to them personally but the school I am attending uses them for parts on Eatons when we need to for our live work. On the clutch issue that is something I am a little concerned about because I know of no one that makes aftermarket clutches for those. And according the phurd fleet website they (the clutch) are only rated for up to 650 lb tq. Obviously I put out a little more than that to the ground. But I would IMAGINE that one of the nice vendors on here would look into such a thing. HINT.





Josh, get ahold of your friend and see if he really did see it done, and if so ask him if he remembers who did it. I would love to get ahold of that person and pick his brain.



Russell

 

[F8LDOSE]

"Your making more than 650ftlb to the wheels?" But remember the NV 4500 is rated at 460, the NV5600 is rated at a measly 550ftlb, and i think the Spicer/TTC (Transmission Technology Corporation) is rated at 660 for the ESO66-7B which they use in the F-750. There's a bunch of guys putting down 1200+ ftlbs on NV4500's, not bad for a trans that was very conservatively rated at 460ftlbs. It uses a 14" clutch, and the heaviest truck has a max GCWR rating of 60,000 lbs!!! I would think a stock clutch would hold any obuse a pickup could dish out. ??? It has an od ratio of . 74:1. The 4500 weighs 200pds, the 5600 weighs 360pds, not sure but the 7 speed may weigh something silly like 600-700 pds. My brother is thinking now of putting a DT466/7 speed in a pickup, for something to do...

 

[onestackdram]

with that said I think unless it looks different when i get my hands on one I wont worry about the clutch too awful much. But if the od ratio is only . 74 thats right around where the 4500 and 5600 is (isnt it?) then maybe it wouldnt be worth it. Mainly because what I am trying to figure out is a way to have my shift points remain somewhat similar to where they are now especially for towing but when I'm empty and running down the interstate to have a final gear to go to that is primarily for run at interstate speeds. Basically I love the way my 5 spd shifts and for towing its perfect. But when I'm empty it SUCKS. 2500 @ 70 mph. That is just too much (in my opinion) to run the engine for long periods of time. So what I'm aiming for is to get her down around 2k approx @ 70 when I'm empty. I know most of you are saying why not just get an overdrive unit. That would be true if it wasnt for the fact that MY 4500 is a POS. I have done all the changes to it. Fully splined her, change to the larger flywhell and so on and so on. So what I am thinking is to just get rid of her all together. But who knows



Russell





Keep all the info coming guys. You transmission people jump in here, you too Vendor people... .

 

[Jff24Gordn]

Getting it to bolt up and a clutch in it is easy. The flywheel cover, the part the bell housing bolts to, is removeable with a few bolts. Just get one that matches the eaton bellhousing. The flywheel and clutch is the same way. You could get Peter at South bend Clutch to make you a good one, because he plays with med duty clutches, too. Now a case of beer and sledge hammer sould get the floor pan into location for it to fit. You will need a custom crossmember. You will need your U joint sizes for each end and goto a heavy duty truck shop and have them make you a driveshaft. The shifter should be close to where it needs to be. I have no idea on speedo.

 

[F8LDOSE]

Whats the highest gear ratio you can get for your rear? with a seven speed you could probably get away using 2. 73's or 3. 08's that should really help lower your rpm's.

 

[baby.driver]

If it is a 4X the highest ratio is 3. 54

 

[Fred Swanson]

I seem to recall an article in one of the 4WD magazines where one of the contributors did this on a 1st gen.



I'll have to dig that one up.

 

[bmoeller]

onestackdram- These may help-



http://www.truck.eaton.com/



http://www.truckpartscenter.com/



http://www.paccar.com/xref/EatonSpeedometer.asp

 

[Alaskaskiff]

Eaton Fuller in a 2nd Gen

There was a guy up in Canada that has posted on this board in the past that did this conversion to a 98/99 3500 4x4 With a Quad cab. Used it for hotshotting I believe.



See this link.



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=36669

 

[dpuckett]

I know a guy here in Poplar Bluff who put a B series in an 85 ish F350 and put a RTO 1066 behind it. I had thought of doing that, and going with a 3. 08 rear if I could find one. To lower cruise RPMs, the only thing I can think of is go with a higher diff ratio. I know a Dana 80 can get a 3. 31, or I know a guy in ColoSpgs who says he can get it. Not sure about your Dana 60 front. For towing, I'd imagine the Eaton 7 speed would have quite a bit lower 1st gear than your NV4500; then you couls take off loaded with your same final drive ratio, adn still turn low RPMs on the highway. But, why are you wanting to keep your 4. 10s for towing? Or is your race truck and related parephenalia that heavy? I have towed a GCVWR of 23K a time or two with the 93 flatbed I had last year, and went 70 in 5th for 300 miles at a stretch with a Getrag. I dropped into 4th up hills, but it was more for keeping EGTs in check than a lack of power.



I guess the conversion would be doable, but I dont think you are going to find much higher of an OD ratio in the transmission, no matter where you go. As for the speedo, Speedometer Service in ColoSpgs can make you a reducer box to any ratio you need. Just hook up your cable (or in your case speed sensor) direct to the transmission, and go over a known distance (say 10 mi) and see how far off you are. Then divide the 10 miles you went by the distance on your odometer, and that is the ratio you need. [ie, mine was going "17. 8" mi over a 10 mi distance, so 10/ 17. 8= 0. 5618, and that is the ratio I had. I tested it, and it is . 25% faster than the road speed- closer than the factory]



Good luck in your search for parts and let us know how it all works out.



Daniel

 

[Philip]

We had a talk about this a while back in the first gen forum. Here is the link for it. There is some good reading in it.





https://www.turbodieselregister.com/forums/showthread.php?threadid=65610&highlight=fuller

 

[onestackdram]

Ok i have done a little research so far. And while the conversion would be EASILY done on my rig (the 97 C & C 2 wd). The numbers werent what I was thinking I guess. What I was hoping to find was that the final drives would be taller in a 7 spd or even 10 spd (checked out both) but in BOTH cases the final drive on eaton trannys are either . 75 or . 74 And last time I checked that was what both nv4500 and nv5600 final drives were. So basically my thinking was backwards. The extra gears are ALL 'up front' not in the 'back'. So in reality I would still have to change ring and pinion gears. So I guess if I would go that far I would just swap them and then go with an OD unit from an aftermarket company. By my understanding either way you go your basically going to get the same thing, except that I wouldnt have to worry about the nv falling apart on me anymore, and I wouldnt have additional components mounted underthere to worry about either.



Still working it out in my head, EXTREMELY SCARRY, I may just give up and buy more POWER...



Russell

 

[Philip]

What you need is a RTOO9513. The last three splits are overdrive gears . 84 . 73 and . 62 and the thing is still rated at 950 ft/lbs

The . 62 is the ratio on a the 13 spd we talked about in the thread I listed above your last post. I think if you check the spec on the 9 or 10 spd you will find them the same outer size as the 13 spd. That . 62 ratio OD would give you a good road gear with the 4:11's you have now.

 

[Jff24Gordn]

Will a twin countershaft trany fit under a dodge? RTOO9513

 

[Philip]

With your year model truck having the body mounted a little lower than my first gen I am not sure. I would think a body lift might be needed.



Go to the eaton website and find the spec's for center shaft to upper part of the bellhousing mounting spec's. then a little carefull measuring under the Dodge should give you a rough idea.

 

[Jff24Gordn]

Well, since my truck is on jackstands with the transmission laying next to it, I made a few measurements. The base of the floorboard transmission tunnel is 21" wide and gets narrower as it goes up. My eaton RT12510 is 23" wide. The main body goes 9" above the inputshaft. This is the same height as the outside of the flywheel. And it aint very wide up that high. So you will either have no legroom, or a 12" body lift for a twin countershaft in a 2nd gen. There was enough clearance to the fuel tank w/o a transfer case.

Where did I leave my sledgehammer??

 

[Crash_AF]

Not sure if you want to twin stick, but it sounds like you need a 'brownie box'. That would allow you to pull whatever you wanted, and then split the overdrive with another . 74 ratio to get your Rs down considerably. There's a thread in the conversion forum about one.



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=82393



Later,

Joe H