(Note: I have arranged this in paragraphs to make it easier to read and sorry if it's a little long. Also I haven't done the install yet but this is how I plan to do it.)

I've done a lot of thinking on improving the front suspension on the 48-52 F-2/3 trucks, like adding power steering and disc brakes plus I want the truck to still be useful and be all Ford.

I think I may have solved the problem of the different frame widths (32" to 34"). The stock twin-I-beam track width is 2" wider than the stock track width. The 75-79 I-beams have a length of 37" from the eye (where the bolt goes though on the end) and 75-91 Econoline passanger side beam is 35" (the Econolines use unequal beams because the engine is offset and the driver side is 28").

To make this work you would require the front clip from a 75-79 F-250/350 (The Econoline's have a wider frame and the mounting brackets are almost impossible to remove) and two passenger I-beams from a 75-91 E-250/350. My theory would require that you to remove all the suspension components and mounting brackets from the front clip. Before disassembly make measurements on how far the radius arm crossmember is from the main crossmember and the location of the steering box. The hardest part is removing the main crossmember as it is welded in. Once that is done, you will have to make some careful measurements as you are going to narrow the main crossmember and radius arm crossmember 2" to fit the narrower frame. Dont's weld it together yet as you have to make some modifications to the stock frame.

Now for the modifications to stock frame. Mark the axle center line on the frame. Remove the front suspension, all spring hangers and motor mounts. In order to compensate for the different frame heights (4" to 6"), I plan on taking middle section of a junk frame I have (You could also buy a 4' piece of 2x6x.25 rectangular tubing. I think 4' should be enough as I don't quite know the exact length required) and removing the top lip of the C channel. Center the L channel on the axle center line with top of the L channel and frame lined up (If you need a better description see the attached picture). Take out a marker and draw a line along the top of the frame. Also mark which area's must be trimmed for the L channel to lay flat. Cut the marked areas off and clamp the L channel to the frame. Now weld along the top of the frame and along the bottom. Now the frame rails should look like a E channel. Now cut a slit in the ends of the main crossmember so it will clear the middle lip (The bottom lip of the original frame. If you have confidence in your welding ability you could remove that lip). I left the main crossmember in two pieces in order for it to be easier to mount it in the frame. Now you can weld the crossmember together but don't weld weld it to the frame yet. Now for the hardest part. Line up the center of the crossmember with the axle center line. This is the most crucial part as it will throw ever thing out of alignment if done wrong.


(Note: I have removed the tranny crossmember since I'm using a 302 and AOD instead of the flathead V-8)

Take the I beam mounting brackets and bolt it to the crossmember. Mark the holes on the side of the frame rail and remove the bracket. Drill the holes and now bolt the top spring mounts and I beam mounts on with grade 8 hardware. You will have to drill the remaining two holes of the top spring mounts on the bottom of the frame. Repeat for the other side.

Remove the spindles from the Econoline I-beams and install the F-250/350 spindles with new kingpins (Note: F-100/F-150/LD F-250 spindles use .8593 diameter kingpins which won't work with the E-250/350 beams but would work with E-150 beams. The HD F-250/350 spindles use 1.054 diameter kingpins which work with the E-250/350 beams). I'm using the truck spindles due to a difference in the tie rods between the trucks and vans. Also install new bushings in the I-beams. Mount the radius arms to the I-beams.

This will require careful measurements and probally some modification to the radius arm crossmember to make it fit perfect. This may take some trial and error.

Install the I-beams and coils. It's reconmended using Urethane radius arm bushings.

Now onto steering as this is when it gets interesting. There are two different steering setups. First there is behind the axle as used on the 75-79 trucks and second infront of the axle used on the 75 & up vans, 80-96 trucks (Note: to go this route you will have to mount the I beams on the opposite sides). It's up to you on how you want to do it but these next two steps apply to both. Since we narrowed the suspension 2" we must narrow the tie rod. The twin-I-beam tie rod is a two piece assembly. The passenger side it one piece and must have one inch removed from the middle (I would reconmend you have this professionaly welded). The driver side consists of 3 pieces. A tie rod shaft, coupler and tie rod end. I would take the shaft to a machine shop to get the threads cut 1" longer and cut 1" from the old threads. Mount the steering box and tie rod. For the steering column you can either get the stock one shortened or go aftermarket. I plan on using a column out of a 65-75 Ford Cabover truck. It looks like the stock column but has built in turn signals and hazard. It is also the perfect length.

You now you have a fully functional indestructable suspension.

Things to considered:
It's highly reconmended using Urethane bushings and new coil springs to keep the suspension aligned. There is also the reputation of this suspension being hard on tires but that is mainly due to the fact that these suspensions were not maintained. The stock rubber bushings have a short life and many trucks had sagging coils thus throwing out the alignment. Also we you get the truck aligned go to a heavy truck center as the average place won't have the tools to properly bend the I-beam. We didn't do any maintence to our '78 F-250 until we noticed the drivers side axle would move forward when backing up. Half the radius bushing was missing and the truck had 184 000kms.

Pros:
-12 9/16" front disc brakes
-Dual cylinder calipers
-Independent Coil suspension
-Front sway bar
-8x6.5 bolt pattern
-Heavy duty kingpins
-All Ford
-Truck suspension
-Stock ride height
-Many different coil spring rates 300 I6 to 460 (F-100/150/250/350 used same size coils)
-Should be able to retain the stock flathead with custom engine mounts, headers but may require the car oil pan for easier oil drain. Would require P/S pump though as I don't know if the earlier 65-74 manual box would work.
-Plenty of donors
-Two choices for steering setup
-Power steering
-Retain stock wheels and look
-Capable of running front dual wheels with factory spacers from F-350
-Keep stock track width
-Could fit any Ford engine with custom engine mounts

Cons:
-Brake compatibility issue. Front disc 3/16 line and stock brake 1/4" line but fixed using 57-72 F-250 axle and disc brake master cylinder.
-Requires custom engine mounts
-Requires modification to inner fenders
-I can't think of anything else right now

Now I want some feedback as if I'm missing anything, if I'm doing something wrong or if there is a way to improve it. I'm still in the planning stages as I probally won't get around to doing this for a year due to school but when I do it, I want to do it right. This could also work for the F-1 if you used F-100/150 and E-150 components but since there is many suspension choices and brake options for them, I left them out.

 

Nathan,
Why not take a stock 75-79 truck frame and split it lengthwise (down the middle), remove 2" from each of the cross members and weld it back together. You could reinforce most, if not all of the cross members with flat steel by scabbing onto the bottom flats of each one and it would be hardly noticeable. This way the frame would be narrowed and your steering geometry would remain correct and untouched.

Just something else to think about …maybe. I like the way the twin-I-beam’s ride and they certainly are tough.

 

Nevermind my last comments Nathen as I spoke without thinking, doing more of that lately. It wouldn't change the front track width by spitting it and taking out two inches unless you moved the pivot end of the I-beams on the crossmember, too much work there. Sorry.

 

http://www.hotrodders.com/forum/jour...age=5&reverse=

This guy on the hotrodders site used twin I-Beams in both his Hot Rods.It,s long but it is a great journal.And if you think he used sbc,s.................just read it.Carl

 

Using 2 axle 1/2s from one side of Econo for both sides of the new install would make the truck handle real "funny", dangerously so, since you will have positive caster on one side and negative caster on the other. The caster is built into the axles so would be near impossible to correct. IMHO twin I beams aren't appreciably better than the stock setup for a lot more work than a complete rebuild. Disk brake conversions, PS setups, etc for the stock axle are readily available.

 

Redlightning, that's interesting but it doesn't show any of the install and he made all custom suspension mounts.

Axracer, Did you know Ford never make the Twin-I-beams with built in caster. The 75-79 trucks had identical beams. They have the exact same part numbers. I can switch the left and right side beams and it would ride perfect (other than having no steering).
Here's a link to a POST that explains it. Be sure to read both pages.
Also there is no 8 bolt disc brake kits for these trucks, a toyota steering box is next to non existant in Saskatchewan (I want all ford anyway) and I can't run front dual wheels on the stock axle.

Keep the feedback coming.

 

51 dueller

Sounds like a major project. I need to ask you why not just weld the F250 front clip to you current frame (just need to taper it). One other thing I thought by 1979 you could get disk brakes on a F250/E250. One last thought if you are going to use 35 inch arms on both sides aren't you going to end up with a 2 inch narrower track then the F2 or am I missing the obvious.

Chuck

 

The 48-52 trucks front frame is 32" and the 75-79 front frame is 34". The track width of 75-79 truck is 2" wider than the F-2/3. So by using shorter beams and narrowing the crossmember 2", the stock track width is retained. I'm using the truck spindles because the vans have a different tie rod. The brake parts are identical though.

 

One more question if running dual front wheels (why?) wasn't a typo then why in the world would you be concerned about a 2 inch difference in tread. I really must be missing something.

There is a fellow on this forum that has mounted a F2 on a late model E350 frame and it looks great. Perhaps he will show up with some more ideas. Good luck in your project.

 

If you were to weld the front clip of the 75-79 truck to the 48-52 frame. You would have to fabricate new cab mounts, radiator mounts, bumper mounts and sheetmetal mounts plus you would have to have to skill to properly weld the two frames together which I don't have. I think your talking about Ameriken, right? It's just he's using the front sheetmetal of an F-8 which is several inchs wider. Also that 1" will put the tires slightly outside of the stock fenders which I would like to avoid and it wouldn't match my rear axle.

 

Why not use the Jaquar front suspension? Isn't it a division of Ford?

 

I'm not building a show truck. I just want to retain the stock 8x6.5" bolt pattern and be able to pull a trailer with a load in the box.