1978 fummins help
 

Hey guy picked me up a 91 Cummins for my 78 4x4. Would I be better running the 518 trans. Or getting adpteer for the c6. Also does the engine clear the engine bay without any mods to the fire wall

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anybody? don't all speak up at once :jump:

Ok for 1, Do you have a shortbed or long bed, And do you have any kind of body lift? And Ac or not. I can say I think the adapter for the C6 is garbage. Both kits require you to hack up the bell housing to clear the flywheel and the nose cone of the starter. Also the C6 shifts by vacuum. The diesel produces boost. American Thunder on here came up with a great way around that. But for me I wanted it simple. I went with the stock diesel 727 auto tranny thats on the cummins. Why?? Because its just about the same gear ratios as the C6,And its made for the diesel. The ONLY problem was the ford 205 transfer case mounting to the 727. BUT there is an adapter for that which I used,Direct bolt up from advance adapters. 50-0207 : Dodge NV4500 4wd with 23 spline output shaft to Ford NP205 transfer case. | Advance Adapters . Easy to do. And a body lift helps,but not required. As for Ac,I modified my pass frame to clear the Ac compressor. Look on one of my post to somebody a couple of days ago. You can see my frame and how the engine sits and all. Any questions just ask.

I agree with what ^ said.

It's a long bed with out ac and no body lift. Well I seen 5hose adapter but am more worried about the dodge transmission reliability. Does the 518 require any kind of control module for the transmission?

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Mud driver mike which radiator did u use

I am using a stock replacement radiator for the bronco..I had the copper and brass years ago but it went bad. Its a 2 row plastic and aluminium radiator. If Im correct the A518 is just like the 727 except it has overdrive. No computer. Just a cable that goes from the injection pump to the lever on the side of the trans for right time for the gears to shift. Think of it this way the trans that came on the diesel were made for it. So they shouldnt have an issue holding up to the diesels. Keep in mind the gas versions of these transmissions will NOT hold up to the diesel. They do share some parts inside but the diesel trans are stronger and the bellhousings are different.

This transmission is supposed to have 10k miles on it since rebuilt. I have no way to prove that but it is painted like it was out of the truck. And after you used the adapter for the 205 how did you mount your transfer case mount

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Also did you run a floor shift to the transmission or was there a way to hook up the stock to it

I actually flipped my T case mount. The way I did everything, My case sits in the EXACT place as factory,just a couple inches higher. And I used the 727 mount and bolted it to my C6 mount and made new holes to the cross member. The 727 came with a 205 on it in the dodges but the front shaft is on the pass side of the axle. Also the 727 trans had a male shaft that plugged INTO a sleeve that stuck out of the dodge 205,while the fords have a female input. The Advance kits has a spacer and stub shaft that plugs onto the 727 trans tailshaft and into the 205. But you have to cut about 3/4 inch or so off the end of the 727 tailshaft. No big deal. I have a B&M shifter on the floor. The shifter pattern is backwards compared to the C6. I made a reversible linkage for it originally but I couldnt get the column to line up and could not tell if I was locked into the correct gear..
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Before I forget. Since I have a shorter wheelbase,I had to shorten the trans. I replaced the diesel tailshaft and housing with a shorter one from an older full size jeep. Same splines and bolt patterns,Just shorter. Because of that,That is why my T case is in the same spot. I did not have to do anything to my driveshafts but bolt them up..you could do the same with the 727. I think the 518 is longer. So you would have to shorten your rear and get a longer one for your front.

Looks like that worked out pretty good. I know the adapter that's on mine is way longer than the one you got. Idk if the transmission itself is longer or not. I will have to look into that.

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Was you able to run you stock ignition switch to the Cummins

Yeah the stock ignition is fine. The only thing that needs power is the shut off solenoid and the timing advance solenoid,which run off the same wire. The wire from the truck I used was the positive that originally went to the coil, the only other wiring you have to do is wire up the alternator to the truck. I have a diagram that shows me how to do that. It works fine. I think I got the diagram from American Thunder. But have it stored in my computer for the future. And for my sensors I bought the "Bushing" kit from fordcummins.com . That worked nice also :tu:

Ok sweet was wonder how that would work I got my old 460 tore out and gonna get the chassis power washed Tuesday and start doing a little fabrication. Also does those adapters for the transmission to transfer case have a power rating or what they can take

I have no clue on how strong that stub shaft is. I asked them the same thing and they said they havent had any issues. It is pretty thick. And im hard on the pedal all the time cause I like to move. And I have 40 inch Ground hawgs. I havent had an problems.

That's what I wanted to hear. How much do you know about the 518 transmission?

Not really anything. I think its like the 727 but with overdrive,and obviously longer. Since I have the bronco thats alot shorter than a pick up ,I was limited on space. So I had to go with the shortest automatic non computer controlled trans I could. I would love to have overdrive,but It aint going to happen. My next step is to take out my 4.56s and either go to 3.73s or to the stock 3.54s. I dont want to lose a lot of power turning my 40s but I need so highway driving back. Just look up the a518 and read up on it. Thats what I did when looking into this whole conversion. It taught me alot about these trans'. And transmissions are a weak area of mine..I can say these 727s are the simplest trans to take apart and reassemble. I think the 518 is similar. :humm:

Yeah basically are the sane transmission just the tail end of mine has the overdrive. I have been trying to read up on them just can't seem to find exactly what I'm looking for. Also did u make your motor mounts or buy them

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I'm debating on weather to run the ford radiator or the dodge one

For the engine mounts,I copied fordcummins design. They wanted $225 for them. Are you F ing kidding me? All it is, is a piece of steel bolted to the block,U channel welded to the steel,and a gusset underneath going to the 2. It took me a couple of hours with my plasma cutter and welder and I was done. And the steel was probably about $40 If I had to guess. We have steel at work So my boss let me take what I wanted. As for the radiator. Its up to you. I wanted to keep things simple and easily replaceable. I figured anything that I could use that was the broncos I did. That way I just go in and say I need whatever part for a 78 bronco. And with the engine and all,A 91 dodge w350 with a diesel. The less mitched matched parts the better. That and the availability of the stock parts.


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Attachment 27739And made this

Attachment 27740To make this.. This pic though is of American Thunders thread.. Check it out here
https://www.dieselbombers.com/diesel...mmins-6bt.html

I was thinking the same thing I don't have a plasma cutter but I can sure make them in a few hours. How did you know how long to make your mounts and where did you find the rubber bushings for them. And I think they are even motmre to buy now from ford fu@kums

I cant remember the length. Ill have to measure them. I had too much and ended up cutting them down,which was fine..As for the rubber,since I didnt know what ford cummins was using. I bought stock dodge motor mounts. I figured out where to drill the hole in my frame and motor mount bracket and bolted them in. A little pain in the ass but It worked.

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Thats what I was gonna do go long and then trim what needed. Also wanted to get the smround bushings like ford Cummins mounts have

If I could of found out what they were using Id do the same. IF you happen to talk to them and find out what they are let me know. I thought at first they were the rubber from the radius arm bushings for my front suspension. So I bought a bushing kit.. They werent..So now I have an extra kit for when my bushings do go. Eventually Im going to make a thread in this section of what I did,but have to get more pictures loaded into the computer for the thread. And pre write it up so its good. And thats what I did was go long,and when they were hitting my coil towers I realized I had to narrow them down,haha

I would think ford Cummins would have just the bushings for repair they can't last forever. Might go to Napa and see if they got anything

I didnt think of that. Asking them for a price of replacements. Yeah they would have to be replaced at one point. And once we get a brand or part number then it should be easy to locate replacements through napa like you said


I just tried to call Ford cummins about those mounts and I keep getting a machine..Ill try later when I can get an actual person............

And they are up to $275..:fu1:

let me know if you can get replacements and i will check with napa and see if they can get them too

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Did you use the stock down pipe or did you have to fab one up

I made my pipe.. I work on heavy equipment now, and the machines I work on have the cummins in them,The 4 cylinders. Well Skytrak keeps having problems building down pipes and mufflers that wont stop breaking. So everytime I have to install an update exhaust. I keep the down pipes for my personal use. They have many different bends and I just cut them in certain places and clocked and welded them to make my exhaust. Also its 3 inch pipe.


Attachment 27747Before I smoothed the welds

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Attachment 27749 Primered. I painted it black high temp engine paint

So you had to go on the out side of the frame or is that the way that worked best for your truck

Thats what I did. The stock dodge has it coming straight down then under the floor and so on. I wanted to keep the exhaust up high and tucked at frame level,So when I go wheeling I dont hit.. If I had an exhaust bender then maybe I would have went with in the frame. That and If I had the money I would of just took it to a muffler shop to fabricate.

I know what you mean. And I tried to call ford Cummins no answer left a message don't look like they are gonna call back. I went to Napa found something that looked simalar from the pictures but they didn't have them in stock so might order one just to see

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What did you do about the seal on the rear of the trans? its keeping my stupid shaft from sliding on all the way.

Dude... I didnt get an email that you asked me a question until today..The 20th.. Anyway the seal on the trans,,,Just remove it. And either silicone the trans to the adapter or get the gasket for it. The stub shaft doesnt fit in the seal and there is no replacement as far as I know. The T-case has a seal of its own,so you dont have to worry about tranny fluid going in,well unless the seal fails,then your T-case will overflow out of the breather. Also, Check how it all fits together first. As the instructions say,(assuming your using an advanced adapter kit) I had to cut off about a 1/4 inch off the trans output shaft. Otherwise the shaft is too long and wont let the whole thing bolt together,pushing the T-case away from the trans. I hope my reply wasnt too late.. I thought I would get a notification as soon as a reply would go on the thread..

Oh its fine I was just looking into that. And I got the advance adapter kit and I haven't test fitted yet but looks like I wont need to cut and from eyeballing it I read that some ppl do and some dont

Yeah same here.. But just my luck I was one of them that had to take some off.. And in order to do that, I had to remove the tail housing. No big deal. Just those bolts hold it on..I got lucky and my gasket was intact. I used some tape around the shaft to get a straight line and used a wiz wheel to slice it off, then used a grinder lightly to bevel the edge..Not too bad

Yeah im hoping to find a set of 2nd gen mounts and then I will assemble everything and get this thing together. Got some highboy springs the other day so the front end shouldn't sag anymore. Also ended up picking up an intercooler cheap so eventually I will be converting to Intercooled.

I don't know about your 78. But I have AC in mine and might plan to go intercooled down the line. The only problem that I see people talking about is the clearance behind the grill for the intercooler. With OUT ac they say you can do it. But with it, might not be possible..I haven't looked too deep into it though:humm:

Yeah mine is a non ac truck. And you have to shave the back side of the grill. And maybe a little metal fabbing

What did you do about your fuel tank ?

The only thing I had to do with the fuel tank was put a fitting in for the return. I drained my tank, removed it, and blew air in it to evaporate the gas and dry it out.. Then I was able to clean out any dirt or anything in there. That and removed the sender to get access into the tank. I had to obviously remove the metal shavings from drilling the hole for the return fitting. I used my wet dry vac to suck everything clean. I then just ran rubber fuel line following my supply line back to the tank. Pretty easy..

So how do you fill up? Did you swap out the fill tube or modify it for the diesel nozzle

I didnt have to do anything to it. I dont have a restricter in it. Back in the 70s when vehicles used leaded gas,the nozzle was as big as a diesel nozzle almost. After a certain year they made the fill tube smaller or had you install a restrictor,so you couldnt put a leaded gas nozzle in an unleaded vehicle. MINE has the full size hole in my fill tube. So the diesel nozzle fits right in with out a problem. Just look in yours and see If you have the whole opening in the tube,or a small hole for the gas pumps.:tu:

Oh ok well my truck had a flat bed when I bought it so I am gonna have to find me a fill tube or make one.

Just hit a yard and find a fill tube from a 73-79 ford truck or 78-79 bronco. Im assuming your looking for a rear tank one. If its a side tank then maybe a rear one will still work. Did you replace the flat bed with a regular one?