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Discussion Starter #1 (Edited)
Hello all,

I have been a long time reader of the 4btswaps forums and I have to say there are a lot of cool projects out there. Thanks for all the inspiration. I have always thought about changing the transmission out on my truck and so a few months after I first bought the truck (some 8 years ago) I found an ad for dead International t444e motor. From that engine I was able to get my hands on the flywheel housing adapter needed for any future conversion. Original plan was a TTC Eso 7 speed swap… At any rate, 5 years ago I pulled a mill I purchased locally home to my place. Trailer plus machine was around 21k (yah, I only exceeded the book GCR by a bit). As I was just on surface roads it wasn’t too bad other than having to really ride the clutch to get the truck moving and having to go into 4 wheel low to back the trailer into the driveway… but, things really got started 2 years ago (April 2016) while pulling my dad’s disabled truck home from Laramie,Wyoming. All told I was pulling around 15k and trying to keep the truck rolling at a reasonable pace was a bugger… there is a reason that the 97 F350 was only rated for 11k towed weight (and it sits between the engine and rear axle). Needless to say it was tough finding a gear the engine was happy with that didn’t require me revving the engine into the stratosphere (how did Ford come up with the red-line for the 7.3??) to keep the boost up and the truck at a reasonable speed.So, after arriving home I started doing some digging and found that someone had done an Eaton Rto 6610 swap in a Dodge Ram. Two weeks of trolling later I found a Rto 6610 on Craigslist and the adventure was underway. Two days and 1533 miles later, this was sitting in my garage...

Rto6610R.jpg Rto6610 gearsR.jpg

Fellow I bought it from thought it had less than 50k miles on it. The swap is actually finished and the truck is on the road, but there is a little more to the saga than I can type up in one evening.

Cj
 

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On your numbers, that 11,000 lbs is the Gross Axle Weight Rating which is the max it can carry, not what it will tow. Max towing capacity is around 10,000 lbs. with a Gross Combined Weight of around 20,000 lbs. I'd guess you were grossly exceeding the weight limits by about 5.5 tons. Can't really fault the transmission for loads it was never designed for. Surprised you didn't break something. The Dana 80 in those trucks isn't unbreakable. With those kinds of loads you'd need the Dana S135 that came in the F550.
 

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Discussion Starter #3 (Edited)
Char... When I looked in the operators manual for the truck it indicates a total towed weight limit of 11k for the 3.55 rear end (sterling 10.25). Everything I have found indicates that the zf5 transmission is rated to 26k gross weight which fits well with your numbers. The Dana 80 will move a heck of a load. Looking at Ford's site the 2018 F350s are rated to 32-33k GCWR on the Dana 80. Admittedly a Dana S110 is tempting...

Ok on to Part 2... (Edited on 3/31/2019 to re-insert pics in text. Also added a few more pics. Internet connection I was on last week was poor at best)

Now for the real fun… Reading various forums discussing various Eaton-Fuller swaps that involved re-mating the transfer case to the transmission all used a cut down knuckle that was then bolted to a coupler that had the mating splines for the transfer case. Not a bad idea, but it would add a considerable amount of length to the whole transmission/transfer case combination. I knew that some transmission tunnel mods would likely be required, but I was hoping avoid modifying the body supports running under the cab that stiffen the cab. After breaking the nut loose (with a 6 some odd foot cheater bar – the aluminum bar is bolted to the output yoke), I got to work dismantling the auxiliary transmission case to have a look at the output shaft.
Rto6610 boltR.jpg Rto6610 Aux R.jpg Rto6610 Aux gearsR.jpg
My hope at the time was that there would be enough shaft length and diameter that I could cut it down then re-spline it to fit the transfer case. I tossed the measure twice and cut once out the door for measure 10 times and cut twice. Here is the test shaft I made out of aluminum.
Rto6610 test splineR.jpg Rto6610 testspline 1R.jpg
After a bit of work on the lathe and cnc mill (yes that is a poor man’s indexer there on the end) and voila.
Rto6610 shaftsplineR.jpg Rto6610 splinesR.jpg Rto6610 splinesdoneR.jpg Rto6610 Auxgears1R.jpg
I did not surface harden the areas I cut as I would have likely needed to re-heat treat the whole shaft and I was worried about warp-age. Eventually I’ll remake the whole shaft and heat treat and surface harden it.
 

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Actually, the Dana 80 came in the the F350 DRW and F450 trucks. Single rear wheel F250HD and F350 got the Sterling 10.25 or 10.50 in later years. F550 started out with the Dana S135 which was actually a medium duty truck axle and was later changed to the S110.
 

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Discussion Starter #5
Time for the next post..

Next it was on the transmission/transfer case adapter. The adapter took a couple of tries as at first glance the bolt pattern on the transfer case is even – but that is most definitely NOT the case on a BW 4407 transfer case. This was the first attempt.
Rto6610 AdaptermillR.jpg Rto6610 Adapterv1R.jpg
On the second attempt I also changed the feet on the adapter to mate with the original rear mount. some of you may notice that the transfer case shown is not the BW 4407 but instead a BW 1356.. The truck was still my daily driver so I borrowed the 1356 to fill in as they both share the same bolt pattern.
Rto6610 adapter v2R.jpg Rto 6610 transtransfer R.jpg
With the the shaft finished and the transmission/transfer case adapter done it was time to tear into the truck itself. As the truck is the full size crew cab, I took the front seats out and rolled the carpet back to expose the transmission tunnel.
Rto6610 cab R.jpg
Transfer case out of the way.
Rto6610 undertruck R.jpg
And finally back to the engine block.
Rto6610 engine R.jpg
The flywheel housing did not fit initially, but hey that is what a sawsall is for.
Rto6610 flywheel house R .jpg Rto6610 1st .jpg Rto6610 flywheel house1 R.jpg
 

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Discussion Starter #6
Hmm... a ten picture per post limit.. continued..

First time I hoisted the transmission into place I did so without the flywheel and clutch in the way.
Rto6610 hoist trans R.jpg IMG_20180919_195521235.jpg
I knew that additional cuts were likely needed in the transmission tunnel and I didn’t want the added complication of trying to center the input shaft more than once. While I was at it I figured a few upgrades to the petal support were in order. Plastic bushings?? Whose bright idea was that? I wish I had a before picture of the worn out pins and linkages.. it was bad. I’m actually amazed that the truck was still shifting as well as it was. Bronze looks a lot better in there.
Rto6610 petal bracket 1 R.jpg Rto6610 petal bracket R.jpg
With the transmission mounted it was time for the sawsall surgery again. In order to maintain approximately the same drive line pathway the transmission hump needed a 2 inch lift at the back end. Cut lines..
Rto6610 cab cut2 R.jpg Rto6610 Cab cut1 R.jpg
Free at last..
Rto6610 2nd cut R.jpg
Transmission in its final placement, the transfer case fit just right. Top of the transfer case still cleared the cab frame work by about 1.5 inches.
Rto6610 trans fitting R.jpg
 

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#2 f/w housing right? I've been debating cutting or body lift to fit one.
 

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Discussion Starter #8
damarble,

It is a #2 flywheel housing.. Came off the international version of the 7.3. I'll detail this in another post, but the short story is that I have gone with all commercial parts from the engine back - flywheel housing, flywheel, and clutch. I thought about a body lift, but moving/extending all the electrical, plumbing, and brake lines didn't sound fun (not to mention that the wife already thinks it is hard to climb up into the truck). i also have a B/W hide a ball gooseneck hitch in the bed that would have needed attention. In the end I just opted to cut the transmission hump to get the transmission to fit. The previous owner did some sledgehammer body work when he put the 3 inch down pipe in which gave me the needed room to get the oval exhaust down past the flywheel housing and bell housing.

Cj
 

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Discussion Starter #9 (Edited)
As luck would have it there were six holes already in the frame right were I could use them to support the new rear mount. New rear mount tack welded and ready for test fitting.
Rto6610 mount 1 R.jpg Rto6610 rear mount R.jpg Rto6610 mount 2 R.jpg
Back up front.. not enough room for the throw out arm.. well as always a sawsall is a mans best friend.
Rto6610 3rd cut R.jpg
Time for exhaust work.. The prior owner of the truck put a 3 inch round exhaust in the truck which didn’t fit with the new flywheel housing. I lost a little over 0.5 inches^2 of area going to the oval exhaust, but it did fit between the body and transmission without any additional massaging (prior owner had done some sawsall/hammer massaging to fit the 3 inch exhaust). Curving the oval lines around the flywheel housing and transmission proved to be a test of patience (cut, tack, cut, tack repeat..).
Rto6610 exhaust R.jpg Rto6610 exhaust 1 R.jpg Rto6610 exhaust lower R.jpg
As I had the back of the engine exposed, I figured I’d add bungs to each of the up-pipes for the future addition of 2 thermocouples (one per side) to monitor pre-turbo EGTs. The Tee also allows me to watch the pressure driving the turbo.
Rto6610 ports R.jpg
 

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Discussion Starter #10
With the exhaust down pipe fitted I started in on the final assembly. A new flywheel, commercial clutch and pressure plate ready to fit. Sure looks nice in there.
Rto6610 flywheel R.jpg Rto6610 pressure plate R.jpg Rto6610 flywheel install 1 R.jpg Rto6610 clutch R.jpg
With the clutch and flywheel in place getting the transmission back in was a bit trickier.. with the exhaust down pipe dangling and the engine tilted down as far as I could get it, I managed to slide the transmission up and into place. I used 3 10 inch long 3/8 bolts with the heads removed as guides. I really dislike the plastic friction plate centering tool (next time I do this I’ll go buy a spare input shaft to use as the centering tool) as the first try I couldn’t get the transmission to line up with the pilot bearing. After about an hour and a half of fighting the alignment in the cold I got the bright idea to lean on the clutch throw out arm to pull the clutch in.. As soon as the pressure came off and the friction plate was allowed to slip, the housings came together and I was in business. As my transmission to transfer case adapter makes bolting the 2 together difficult I pre-assembled them prior to mating the transmission to the engine (sorry no pictures.. my photographer didn’t want to join me in the freezing cold – this happened over Thanksgiving 2018). After raising the transmission into position I added the new rear member and bolted it all together. I also put the original rear member back in as extra insurance.
Rto6610 final install 1 R.jpg Rto6610 final install R.jpg Rto6610 final install 2 R.jpg
 

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Any particular reason for 2 EGT sensors? That reading is normally take just prior to the turbo or just after it so only 1 sensor should be needed. The drive pressure can be a very useful reading. Do you plan to read it with a mechanical gauge or electronic?
 

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Discussion Starter #12
Char,

There were a couple of reasons to my madness... The Y pipe going into the turbo keeps the exhaust streams separated right up to the turbo inlet, so not a good place to get an over-all reading. I didn't want to drill and tap the turbo snail and have the thermocouple interrupt the exhaust flow - though the flow is probably pretty turbulent through there anyway. Having two sensors allows me to monitor each bank of cylinders. I have read instances where a connector in the "reusable" valve cover gasket has failed and the person diagnosing the problem has found it checking the manifold temps. Having the two sensors seems like a reasonable way to compare the health of the two cylinder banks. As for the drive pressure - (please jump in and correct me if I'm wrong...) I was reading somewhere that ideally, the turbo back pressure and boost pressures should be about 1 to 1 and anything other than that could be an indicator of a problem or inefficiently operating turbo. Currently I have a pair of mechanical gauges sitting in the cab for the boost and back pressures. I also still have the EBP valve in place.

Cj
 

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Discussion Starter #13
I have to apologize for lack of pictures in this next section.. I actually did most of the work described here much earlier in the process – long before I put the transmission in the truck. I knew when I started that the Eaton shift tower was going to be too tall and too far back. In my initial guesstimates I figured the shift tower would end up 5 to 7 inches behind the original position. So after taking some careful measurements and sketching the Eaton tower up I started to change the pivot point until I had a reasonable compromise between a reduced height tower and how much “swing” I would have at the top of the shift lever. As my new idea didn’t work with the original tower parts, I designed my own gimble and a friend with a cnc lathe machined a new finger to mate with the shift forks.
Rto6610 shift finger 1 R.jpg Rto6610 shift finger R.jpg Rto6610 shift gimble R.jpg Rto6610 shift gimble 1 R.jpg
A shot of the new shift tower bolted to the transmission.
Rto6610 shift tower R.jpg
The fellow I bought the transmission from picked up a vertical lever/shift tower for me when I drove up to purchase the transmission. As that wasn’t going to work I cut it all up (and down) beat it up with my press and welded it back together as a shortened 90 degree tower.

Rto6610 shift lever R.jpg Rto6610 shift lever2 R.jpg Rto6610 trans hump R.jpg
Most of the re-assembly happened this last January (2019).
 

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Discussion Starter #14
On to the clutch setup.. Typically these transmissions are hooked up with a mechanical linkage, although I have seen a hydraulic setup that bolts to the bottom of the bellhousing on ebay. After digging around under the hood I decided that it might be easier to keep the hydraulic system verses trying to come up with a set of rods and pivots to maneuver the linkage around all the lines, electrical and chassis parts that were in the way. My first attempt was a disaster.. I had measured the bore and stroke of both the master cylinder and slave in order to calculate the correct offsets for the various parts of the clutch linkage. The lever arm on the transmission itself required a linear move of about 2.2 inches to disengage the clutch and squeeze the clutch brake. A little math and here is the first linkage.
Rto6610 slave fit1 R.jpg
All mounted and ready to go.
IMG_20181224_171734938.jpg Rto6610 slave fit3 R.jpg Rto6610 slave fit2 R.jpg
Hmm.. just one problem with version 1, I can only get partial release of the clutch. Not even close to enough movement to get close to the clutch brake. After some head scratching, I determinedfound that Ford does not use the complete travel of the master clutch cylinder (about 1.6 inches), instead the system only uses about 1.20 inches of travel. This translated into a slave movement of about 0.5 inches where I was expecting about 0.75 inches of movement. For reference the master cylinder bore is 0.875 inches in diameter and the slave cylinder bore diameter is 1.25 inches. At this point I had two options. One – move the slave cylinder linkage closer to the pivot (costing mechanical efficiency and it puts lot of stress on the pivot). Two – find a different slave with a smaller bore for a longer travel. After a bit of looking around I settled on the slave cylinder out of a 2002 F350 with the 7.3. The new slave has a bore of 21 mm or about 0.827 inches which gives a stroke of 1.36 inches with the original master cylinder. So still not enough stroke for a direct push, but the longer stroke of the new slave did allow me to move it connection point farther from the pivot and still get the needed 2.2 inch push distance.
Rto6610 new slave 2.jpg Rto6610 new slave 2.jpg Rto6610 new slave 3.jpg
 

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How did you get the rear trans bearing tight with your transfer case adapter, most trans' use the rear nut to tighten the rear bearing, which makes it hard to transfer torque around that nut? I adapted an NP-540 series to an NP transfer case. Apparently Ford put some RR's in Expeditions using a Ford adapter which is rare.

Ed
 

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Discussion Starter #16
Ed,

"How did you get the rear trans bearing tight with your transfer case adapter,"

My adapter fits over the Rto "rear bearing cover assy" which retains and clamps the outer race of the output bearing. So my adapter is not actually tight with the rear bearing. Eaton machined a lip into the back of the "rear bearing cover assy" which allowed me to use it as a means to center the adapter.

"most trans' use the rear nut to tighten the rear bearing, which makes it hard to transfer torque around that nut?"

When I cut the shaft down and re-splined it I was able to reuse the nut that retained the yoke to hold the shaft tight to the inner bearing race (as it would have done without my modification). Take a look at the last picture in post #3 you can see the low speed gear, then the bearing, then the original nut and finally the splined section.

"I adapted an NP-540 series to an NP transfer case. Apparently Ford put some RR's in Expeditions using a Ford adapter which is rare."

I have read about Ford using a RR, but have not seen one... Being rare makes it unobtainum so I looked at what I had to work with and came up with a work a round.

Cj
 

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A long reach socket to get the nut to 500 ft/lb or is it just FT?
Cheers Steve
 

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Discussion Starter #18
Steve,

500 ft-lb?... the RR rebuild manual I have says 400 to 450 ft-lb on that nut. I used an open end wrench and I got it up to about 200 - 250 ft-lb or so via my "calibrated" arm. As there is no yoke hanging of the output shaft now, I thought it would probably be ok to go with a lighter torque. Sometime in the future I would like to turn/spline a new output shaft from raw stock. I'm also toying with the idea to redesign and machine a new transfer case - one that is just on or off (don't really need the low range anymore). If I do that, I'll devise a way to bring the 2.25 inch shaft through the transfer case itself.

Cj
 

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cj, yep maybe 400/450. Have not looked at that torque for awhile. Just had 500 in mind, possibly thinking of larger transmissions,

Agree with out the yoke on the shaft it should only be holding the bearings in place.
Cheers Steve
 
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