I have a LWB 1980 F100 with a t18 and a 351w that I am wanting to swap to 4x4. I have a donor 85 bronco with complete front suspension, C6 transmission and transfer case, cross member, driveshafts, rear axle, steering column, and wheels. I can swap the transmission and shifter column and all just fine on my own along with the rear axle but when it gets to the front I need a little help with which parts to take and use, which ones to have new bushings and such install, and which ones to leave on the bronco and take off my truck. The front axles on the bronco are 5x5.5 as for the need to swap wheels so I know I will have to have my tires mounted and balanced. I am converting to the c6 as for the need for the auto column. I know I need to cut a hole for the transfer shifter. Some things along with the front suspension and such I have questions with is how long of a driveshaft will I need? Will the rear bronco one work on my truck? I would think it would be to short because of the long bed. Do I need a tranny cooler? Can I rob the back up light pig tail and speedo from the bronco?
Anybody that has done this swap please chime in with your comments. I will take any help I can get.

Thanks, John

 

You'll need drive shafts from a F150 4x4 lwb with a C6 and the same rear axle you're using. Just watch the transfer case output. The bronco is likely a flange where the F150 are usually a slip yolk. You may need a custom shaft, so keep the bronco shaft for parts.

Your truck has the 9", the Bronco will almost certainly have the 8.8 axle. The 9" was phased out in 83, but a couple have popped up post 83 that were factory installed. I guess ford found old stock lying around. 2wd springs are 2-1/2" wide, where the 4x4 springs are 3" wide. I've seen people use the 2wd springs and people swap the spring hangers and use the 3" springs. I have a 2wd 8.8 in my 4wd F150, so they should swap back and forth.

Onto the front, the 4x4 beams will replace the 2wd beams. Replace the pivot bushings while the beams are out. The radius arms will go into the 2wd frame brackets. Use new bushings.

I have you'll just have to swap floor covers since you are starting with a manual. If not, use the bronco cover as a template and cut it out.

Hopefully someone else will answer your other questions.

 

They did make lwb pickups with the external rear slip joint, my 1980 had one. I don't know how hard they are to find though. If you find a deal on a rear shaft and the transfer case out of a 8ft bed pickup, you could get the transfer case too if it doesn't match the Bronco transfer case. They all bolt up, just make sure you get the shifter or the shifter out of the Bronco will fit. They did change the shifter around sometimes.

You need the tranny cooler for the c6 in the radiator. Just swap the Bronco radiator in place if it's in good shape.

You have everything there to make the swap except the rear shaft. Like the other poster said, I would replace the center pivot bushings before installing the Bronco stuff, as well as the radius arm bushings. After that, any other work that the Bronco frontend needs can be done after it's installed.

 

The radiator support was changed some time between 80'and 85 so the radiators won't easily swap. However, you can swap radiator supports and then swap radiators.

You should be able to use the backup light wiring. As for the speedo, I'm not sure what you are asking. But the Bronco and pickups used the same gauges so you can swap or keep what each truck has.

 

This Bronco for some reason has a slip joint yoke on the transmission side and also a 9 inch in the rear. I know it is a 9 inch because I already pulled the rear axle to swap the third member into my truck before I thought to go 4x4. The axle housing is sitting outside by my garage. When it warms up a bit today I'll ****** the axles out of it also for the 5x5.5 lug pattern in the rear. When I swapped the 351w out of the Bronco into my F100 the radiator bolted right into my core support without any problems. I was going to swap them but the Broncos was rusted out so I tryed it and it fit. I will try both the Bronco and F100 shafts and if they don't fit I will call around to see how much it will cost to shorten the F100 one and compare it to the cost of a junkyard one. As for the speedo I was wondering if the C6 lower cable would attach to the F100 upper cable but after looking it should swap out no problem. My truck did have the column shift 3 speed from the factory so my floor pan is already for an auto. I probably just fab up a plate to cover the T18 hole and cut a new one for the transfer case. Im just going to leave the 2wd rear springs and hangers because Im not going to be doing any extreme offroading or any thing. This truck is a daily driver and mostly just checks cattle and maybe runs through a puddle or two once or twice. I have the tranny cooler but not the lines because they got bent when I pulled the engine from the Bronco. Where would be a good place to get these for cheap? Also while I have the C6 out I was thinking of a shift kit. What is the best low budget one that ya'll can think of?

Thanks, John

 

1980/83 F100's were not available with 4WD or 351W's.

Some 1980/83 F100's have 5 lug wheels on a 5.50" bolt circle, some have 5 lug wheels on a 4.50" bolt circle.

 

Pull the carpet on the bronco, there should be a removable cover for the trans with the appropriate hole cut. There will be an indent on the f100 where it goes, but it won't be cut out. Just cut it out and use the cover. Unless it's rusted out...

I think there are flange type transfer cases for the f150. My 86 has a slip style, but my 87 f250 has a flange.

 

Would it be okay to use the slip type in the truck? Would it be okay to weld the floor pan in?

 

Why would you want to weld the floor pan in place? It's nice they made it removable for jobs like this. You need to go ahead and pull the seat and then pull up the carpet. Switching the pedals out is a pain in the rear, and it's so much easier working under the dash with the seat out and being able to lay in the empty floor to work on it.

When I swapped my pedals out on my 89, I found they ran the speedo cable right through a opening in the pedal assembly. So to get it out I had to take the instrument cluster out a little bit so I could disconnect the speedo cable from the speedo. You start to wonder how much you are going to have to tear the truck apart, but it goes back together fairly quickly. It all bolts in place.

For the tranny lines you could make your own. In most stores they have a rack with universal brake lines and metal fuel lines. And they sell benders also. Do a little head scratching and you should be able to piece together some lines that will work. They also have couplers. Make the line out of two shorter lines with a coupler will make it easier to fish into place. The larger fuel type line should screw right in to the tranny. I can't remember if it's 5/16" or 3/8" line.

 

Would the braided fuel lines they sell for carburetors and such work or could regular rubber hose work? The steel lines are only bent at the end where they connect to the radiator so I might be able to savalge them I just don't know how. Could I bend a short peice and flare one end with a fitting on the other and solder it to the originals or will that not hold up? As for the pedal assembly I planned to just remove the clutch pedal. Is that not possible?

 

I guess you could just try and remove the one pedal. Look at the Bronco pedals and make your decision, I thought they looked different in a auto setup.

If most of the tranny lines are still good, you could buy a short piece and splice it in. Don't use hose, that is something else that can get old and leak. Go to the hardware store(the auto store should have them too) and buy brass compression couplers. That will make a nice metal to metal connection. If you buy a short piece of flared universal line at the store, it will be already flared with the nuts so you won't have to do that, just cut it in half and use the ends. The compression couplings are made like the picture below.

 

How would I get the alignment close enough to get it to a shop? Do you just tourqe everything down to a spec or do you have to count the threads on some? I have never done any suspension work before and am a little confused. Also, are the shocks and coil springs in the front different between the 4x4 and 2x4 models? How do I take the front brake assembly off and how far do I need to breake it down?

Thanks, John

 

You need to look at the truck a little bit underneath and have a plan of action. If you look under the truck and don't have any clue at all what is going on, I suggest you take it to a shop and let them do it.

After looking at the truck and a manual on what's called what and what everything does, come back here with specific questions. Or get someone to help you that has some experience with suspensions.

It's not too difficult, but I am a little uncomfortable trying to lead you through if you have no knowledge at all, you can get hurt on some of this stuff. What I would do first when you think you can do it or have help, is to take the Bronco apart first. Let that be the guinea pig.

If you knock the steering linkage loose and don't turn any adjustments(you should not need to) the alignment should not be affected. When you are done you certainly need to go get it aligned, but if you put the suspension under the truck as an assembly, it should be close in alignment.

 

I got the Bronco torn all the way down to frame today. That in itself was a rodeo! Tomorrow after school I am going to call a local shop and get a price to swap the suspension. I just hate to spend money on something I can do on my own but I can't have this vehical down for much longer. If I have to keep riding the bus I am going to go crazy.