I have have yet some more conversion questions, that I am trying to put into some order of sense for myself please respond if you can help or have experience in the following.
Project:Convert 1991 Crew Cab Dually F350 7.3 diesel with a A4OD from 2 wheel drive to 4 wheel drive.

1.Transmission- I want to convert to a standard transmission, what are my choices, I think I have heard that there are heavier duty transmissions that will work with this engine that perhaps came out of F450's, F550's or older but stonger tranny types.

2.Transfer case- I know very little about standard reference # for this essembly, is there only one choice or are there multiple choices?

3. Rear end- Do I need to convert to a particular rear end or can I retain the one I have?(a 410)

4. Front end- I have been told that I need to convert to a Dana60 for this project, are there any other choices.

5. Final question- I have thought of converting to 4 wheel drive using 1 ton front and rear ends that are not duallys since I know that there are F350's that are not duallys(I would use spacer adapters to create duallys on the rear end)the 2 reasons for this is the possibility of parts might be more easily acceptable and perhaps even more important the availibility and selection of non-dually wheels are vastly better. If anyone knows about this option your response would also be appreciated.

Thanks,
Smashing4455
91Crew cab dually 7.4

 

I have tried to send you an email to respond to yours. You have your options set to not recieve email so I have been unable to reply.

I would just use the Dana 60 front axle and the transfer case (should be a Borg Warner 1345 in an 85) out of your junkyard find.
Be careful of the front axle, most 85 models had either a Dana 44 straight axle or the Dana 44 IFS. Neither will stand the torque of a diesel very well. I have a Dana 44 IFS, it costs me about 600 dollars on ball joints and tie rod ends every other year. I also break an axle about once a year, that runs about 300 dollars. I do plow snow though, you probably will not do much of that in Texas.
As far as manual trannies I have seen a M6HD Ford six speed apart. They look like a beefy tranny on the inside. Your only other choice is a ZF 5 diesel tranny so you do not loose the overdrive you have now with the A4OD automatic.

The M6HD or ZF 5 must be out of a diesel truck, the gassers will not bolt up.

A non OD tranny will make a good dent in your fuel mileage.

If you are going to run duals, I would leave the rear you have in the truck now in it. Spacers are not very good if you haul any weight. They put a strange load on the bearings that is not good for them.
I think your speedo pick up is in the rear axle on your 91. The rear out of an 85 will not have a place to put your speedo pick up. They were in the transfer case in 85.
I also think the 91 trucks used the Borg Warner 1356 transfer case. Either is good, the 1356 may be easier to hook up though.

 

David,
Thanks for all your ongoing help, i always am amazed that you don't get tired of so many questions,usually repetivitve ones as in my case. I will change my settings to recieve E-mails.
A couple of follow-up questions
The M6HD is a 6 speed if I am understanding you correctly, right? If so is this the tranny that I would lose Mileage with verus the ZF5? Is the ZF5 an automatic?And what years did these models come in.
In regaurd to the Borg warner 1345 transfer case, if the front axle on the 85' is a Dana 44 and the transfer is a 1345 then I am still okay using the 1345, right? and if this is correct is the drive shaft(front or rear) of any use to me?
Thanks for the non-dually info I won't be doing that. One other question please give your quanities and prefences on antifreeze with sca's, i used your formula to change it last time and the computer that I had the info on crashed.
Thanks agian for all your wealth of knowledge,
Smashing4455

 

I like to learn things, and am not afraid to share my info with others.
My grandfather owned the Ford garage in my home town and we had a large farm.
I have been around mechanics and Fords for as long as I can remember. When I started working on trucks they were 6 volt positive ground, the battery was under the passenger side floor board, and they all had starter pedals even the cars.

The M6HD is an overdrive 6 speed manual tranny, that will give you good mileage.
The ZF 5 is also an overdrive 5 speed manual tranny, it will also give you good mileage.
The T 19 manual tranny is a direct drive 4 speed that will not give as good mileage.

The ZF 5 has been around since the late 80's, not sure of the exact year.
The M6HD is a late model tranny that has only been around for a couple of years.

The high gear final drive ratio for each is:
M6HD = .72
ZF5 = .76
T19 = 1
A4OD = .71

So the M6HD in OD would be almost exactly the same RPM at 70 MPH as your A4OD in OD gives you now.

In 91 the transfer case that was stock was the 1356. There are a few differences in the linkage from the 1345.
I would probably try to get a 1356 and the stock linkage for a 91 250/350. It may cut down on the fabrication required to install it.

As far as the antifreeze I run 4 gallons of VC7A premium gold from Ford, and two bottles of DCA4 also from Ford. Finish filling with distilled water, 3 gallons will fill the engine and the overflow tank.

 

Thanks for all the info I'll will give you an update as this project moves forward
Smashing4455

 

Don't forget that most of the 4x4's used a front mounted shackle instead of a rear mounted one. There are kits that will give you a lift and move it to the rear for a much smoother ride. If the e40d's are the same as the c-6 internally or similar, you can swap the output shaft in the tranny and bolt on a t-case with a lot less effort than swapping in a manual. From my experience manuals are much more durable, but in a lot of slow off-road situations, or in town the auto is so much nicer. Besides, most of my past and present girlfriends hate stickshift trucks. Running an auto also saves having to work with the dual mass flywheel that I am really beginning to dislike on my truck.

In your other post about gears and mileage you are talking of swapping to 3:55's. Knowing now that you want to convert to 4x4, I would tell you to stick with your 4.11's and add a lift kit and bigger tires if you want to go very far off-road with a dually. Especially an extra-cab or 4 door. They really need a little more clearance if you go any farther than down a dirt road. In any kind of sand or mud, you will really appreciate a little lift and a good limited slip in either or both ends. I am running the factory l/s in the rear of mine and an easy locker in the front. Right now I am really pleased because I don't get any of the harshness of a locker in the rear in daily driving and I have at least 3 wheel drive once I get into the nasty stuff. And by nasty stuff, I don't mean mud, around here I've been exposed to this really powdery sand that is bottomless and sucks power like mad. Without a locker in the front and a l/s in the rear I'm pretty sure I would have had to shovel my way out at least once in the last month or so.

Good luck, and don't worry about the dana 44. If that's all you can afford, or find. They are pretty stout axles as long as you drive with finesse and not brute force. If your idea of fun is bouncing the tires off the ground at full power, the upgrade to whatever you can get. For me right now, the dana 44 ifs with a dana 50 centersection and inner stub shaft is working perfectly. I've never had problems with the ball joints or anything else yet, but I don't plow snow for a living either.

 

What do you drive and how long have you been driving it?

 

My diesel is an 87 F250 with 6.9 and 5 spd. My toy is a 78 F150 and my daily driver is a 98 Toyota Tacoma 4x4. I've been driving the 78 since 1985 and the tacoma since 02. The diesel was new in March.

I grew up on trucks, never knew any different. First car I owned I was 21, never want another unless it's for the family, or for going even faster than the 78 will run. My training car was a C-50 chevy 2 1/2 ton truck with a silage bed on the back. I learned to drive it by sitting next to my dad while he ran the gas and I shifted and steered. I don't think I was much taller than the front tire when I learned how to split shift with a 2 speed rearend and steer with at least 1/2 turn of play in the linkage.

I only hope I can teach my kids the same things that my dad taught me.

 

jfinlen, you drive that IFS 44 25,000 a year like I do and you will see how often you repace those ball joints.

I only drive my 250, and I drive it every day and every where I go.

Then put bigger tires on it and watch them wear out even faster.

 

its a mute point on the 44 I have a great truck with little problems right know and the last thing Im goning to do is retro the the axles with anything less than 1 ton equipment. Jfinlen I do have a question for you ,I am not very familiar with the terms your using in regaurd to the term "I/s" and "easylocker", is this refering to the a limited slip axle? Please elaborate! P.S. there is a guy I'm talking to that is interested in selling his dana60 at a pretty good price. so hopefully that willbe taken care of.
David another question for you, or Jfinlen for that matter, Ihave been told that I can get a ZF tranny with a PTO do you know if thats true?