1980 F100 2wd Front End Retrofit
 

My 1980 F100 has a broken radius arm on the driver side. I'd like to replace it, but I haven't been able to find many new parts for these trucks.

I also have a 1986 F150. Can a person retrofit the newer front end onto the older truck? I'd really like to be able to find parts for my truck.

Here is a to an amazon part. Otherwise you can google search by part number: F1TZ-3A360-B

I don't think that part will fit my truck. If I recall correctly my truck's radius arms look different. I believe my truck is the light duty f100 with the king pin axles and the small bolt pattern.
https://cimg5.ibsrv.net/gimg/www.for...5412ff7625.png

1980-81 : F100 - F150 radius Arm # E0TZ-3A360-D

The big difference is 80-81 used a forged radius arm and 82 - 86 used a stamped radius arm. Outside of that kingpin or balljoint I see no mention of it making a difference on the part number for the radius arm.

No listing on ebay but you might be able to find one listed online if you feel inclined to do some digging.

Thanks Rusty. I have an 82 F100 and mine are ok - surface rust but solid so I've never looked for these. Are the 87-96 the same fitment as the 80-86?

The frames are the same up to 1996 I believe. The headers I got for my '82 F150 are listed as fitting 86-96 year models and I looked up the OEM Y pipe part number as these shorty headers fit oem Y pipes and the Y pipe was the same in 1980 as it was in 1986 which tells me 1980 - 1996 should be the same frame.

But that doesn't mean the suspension stayed the same how ever. Like 80 - 81 was forged steel beams while '82 and up was stamped steel.

My 81' F100 has the swiss cheese frame, so I'm not sure the broad generalization of the frames being the same is accurate.

Has anyone here actually used the later radius arm on the older truck, or has anyone actually swapped the newer front end onto the older frame?

The stamped front beams were not 1982-up...they were only around for a short time, possibly only in 1982. When they went to the ball joint front ends, the beams were forged again.

So there were a couple different front beams with the 2wd king pin trucks (Forged, and stamped). When they went to ball joints (1983?) then they all became the same thickness (5") up to 1996.

There are no replacement radius arms available for the 1980-1986 2wd trucks that I'm aware of, new or aftermarket. They are available for the 1987-1996 trucks, but they are different on the bushing/frame end. I have a set of the 87-up radius arms on my 1984, and they fit just fine as long as you use the 87-up radius arm bushings.

For the 1980-1982 2wd kingpin trucks, there are really only two options to replace the radius arms. Repair the old ones (weld in new rods that usually wear/rust out inside the bushings), OR, swap in a newer ball joint front end.

Well my '82 has ball joints and it has stamped front I beams. From all I read '82 was the first year for ball joints 81 was still kingpins.

My bad on the stamped beams...sorry, I thought they were only on the very end of the kingpin trucks. Maybe it was just the very beginning of the balljoint trucks. In any case, the stamped I-beams were only around very briefly, maybe only in 1982. The beams went back to being forged shortly afterwards. Numberdummy could explain better.

See the link below, Number Dummy shows the dates when the stamped beams started and ended. Production from 8/81 to 6/83. That would be model year 1982 and most of 1983.

https://www.ford-trucks.com/forums/1...mped-axle.html

My 1984 has forged beams, so I haven't paid close attention of the the pre-84 trucks;).

lol I don't focus on much outside of '82 unless I have to. Such as exhaust which is where I found out 80 - 86 use the same Y pipe so a '86 - '96 shorty header should really state it fits 80-96 as the Y pipes are the same. Or the sending unit, which I might add fuel injection to my 82, simple just toss on a '84-'86 16gal saddle tank and throw in a '84 sender to maintain functionality of my oem fuel gauge as ohm values changed in '85.

Outside of that I only know about 82 as it mainly pertains to my truck. I know my is stamped and that kinda bums me out as I got it in my head forged beams would be stronger than the stamped beams I have.

I have never personally done it, but people in here do it all the time. The most frequent reason is because they want to lower their truck, and the company that makes the lowering beams only makes them for the newer trucks like you mentioned. So they swap the complete frontend out of a newer truck under their older f100, and then at the same time they install the lowering beams.

If you take the whole thing complete, newer radius arms, newer axles newer spindles, newer brakes and the 5 on 5.5 wheels, the whole thing will bolt in under your truck. If you have the small car pattern rims you can swap the rearend out of the later f150 in place and that will give you the larger pattern wheels for the rear also.

P.S. If you find a 4x4 f150 up to 1996, and would like to go 4x4, you can bolt the 4x4 frontend in place also. Of course you would have to change the transmission also to get the transfer case to bolt up. But the 4x4 is a bolt in also.

Thank you for the information. I'll try researching "lowering 1980 F100" and see what I can find.

What was meant was the dimensions for the frames are all the same. So the parts as a whole will swap between them.

You will not find much for the 80-81 kingpin trucks.
DO NOT cut coils to lower the front this will only cause other issues you cant fix ......... easy.
DJM beams I think now list a drop beam but it is only for 1 size kingpin and our trucks could have 2 different sizes. It is my luck the suspension I went with, I have both size pins, is not the size DJM makes them for. http://djmsuspension.com/
For me to use the ones DJM makes them for I would need to get wheels for as I don't have any wheels for it, oh also need to swap the rear axle to match wheel bolt pattern.

BTW IIRC the lowering beams are for the 5x4.5 wheel bolt pattern kingpins NOT the 5x5.5 pattern.
As you can tell I have looked into this and what I found.
Dave ----

I agree no cutting of coils. If you want to lower check with someone like Eaton Springs tell them "year/make/model/accessories" and tell them you are looking to lower the truck they can custom make you a set of springs to OEM specs that will lower said vehicle.

Only thing is going from memory I believe 1.5" is the lowest you can drop before you will encounter alignment problems. Could run into it a bit sooner though especially on a kingpin truck as I don't know a whole lot about them when it comes to lowering.

I didn't mean to get this thread on a tangent by mentioning the lowering thing. I just mentioned it because that seems to be the main reason for frontend swapping.

Well people need to know. it can cause unneeded headaches.

For us kingpin truck guys yes that is the "best" (only) way to do the lowering.
But I have seen it posted the later year trucks had better front disc brakes?
I don't see how but if you need the spindle on out to match the lowering beams then that is the only way to go.

I would like to get my truck a little lower, looks like a 4x4 now and it is stock using used springs F/R so don't know why?
But when the new pins wear out I will look for the later parts and do a lowering beam swap.
Dave ----

One thing that is easy to forget when assembly a project. Before tightening any of the frontend pieces/bushings, you need to put the weight of the normal vehicle with the engine installed, on the ground, on the wheels and tires, before tightening the front suspension pieces. On these trucks that would not be much, just the center pivot bushings and the radius arm bushings. And of course sway bar bushings if you have those.

Unless you upgrade to the Polyurethane bushings then it doesn't matter as they are free moving bushings unlike the old rubber bushings.

I have poly in the front when I rebuilt it but rubber out back.
I did not know that about the poly bushings.
I still have to nut & bolt the whole truck before it is put on the road as I dont remember what is and is not tighten now.
Dave ----

So this thread went off the rails

Anyways, I searched the forum threads for "lowering 1980 f100" and I didn't find many direct posts, but I did seem some users that had done so.

I was wondering if anyone here remembered any threads that had thorough and accurate information on such a task. If any does remember can they share the thread?

Not sure what you are looking for. It's a pure unbolt and bolt back in operation. Of course what you bolt in should be in good shape. I would use new pivot bushings and radius arm bushings. You might as well wait if the swapped in frontend needs balljoints. It would probably be better for it to be bolted to the frame to hold it in place while you press the balljoints out. Or once you bolted it in place you could drive it to a shop and let them do it.

Yep the polyurethane bushings you have to remove the rubber from your old shells and grease them so they are not physically attached to the shell or the pivot pin so they basically can move freely. Unlike rubber bushings where the bushing is vulcanized to the center pivot bushing as well as the outter shell then you have the teeth in the center pivot bushing that is supposed to bite and lock the bushing in place.

I just put mine together bolted it down torqued as close to spec as possible and then let it ride.

I posted in this thread what you have to do to lower the kingpin front suspension trucks.
In short if you have the small kingpins then DJM sells drop beams for the front & hanger kit for the rear. You will have to know the kingpin size for this.
or
You buy a complete ball joint front suspension like Franklin posted, buy the DJM beams to work with the ball joint parts and swap everything over to the drop beams and bolt into your truck.
I have an 81 kingpin truck so I know what you have to do as I looked into this.

Dave, he has kingpins in his truck now so he would need to buy the complete suspension for a ball joint truck and the drop beams and swap the parts around as needed.

I know you have to remove the rubber but keep the outer & inner shells. I soaked the bushings in old gas for a few hours then put flame to them and burned the rubber out. Worked really good, little clean up with wire brush, paint and they were ready for the poly bushings.
Never gave much thought to how they move over the rubber ones.
Dave ----

Have you ever used the drill bit method for removing old bushings from the shells? You take a fairly good size drill bit like 3/8 or so and you run it in reverse put it near the edge of the inner pin and let the drill bit walk around it will pull the pin out. Do the same with the rubber between the shell and it will walk the rubber out quick and easy.

I have heard of the drill bit trick but I had the old gas.
I hung the 2 beam assy. from the rafters in to 2 tin cans and let them soak.
Beside who doesn't like playing with fire LOL
Dave ----

I didn't go to all that trouble. I put a jack under my I beam pulled the pivot pin bolt out and lowered the jack just enough to get to the bushing did the bushing then jacked the I beam back up into place. Took me about 10 minutes to do both sides vs a complete disassembly of the I beams.

It was already out so was no trouble.
I was going to use the parts truck front suspension, has it cleaned painted and installed then found my wheels didn't fit.
Found yiy can't swap hubs or spindles because of the kingpin size.
So out it came cleaned, new kingpins and why I was going to use the other, new bushings other reason for the other, paint and installed.

It would have been nice to just drop the pivots drill out the rubber etc and be done I had to do it the hard way.
Dave - - - -