I'm getting close to shortening the frame on my 1956 Ford F-600. I just found a bed that will work for me, it will still need some playing with, but over all should work out well for me.

I'm pretty sure I have it all worked out but I'd like to run it by those who have done it to avoid a stupid mistake.

I was going to move the axle up, cut off the rivets and use bolts, but I've decided that it will be a lot easier to cut the frame. I had thought I would have to add more length to the end of the frame for the bed (the back wheels are close to the end) but after measuring it shouldn't be a problem, and shortening still strikes me as easier.

I plan on doing the cut the same way as 53ChopTop did on his Chevy:
http://www.jalopyjournal.com/forum/showthread.php?t=319393&highlight=chevy

With the plate in the back as well.

Any tips on keeping that all straight? Best places to measure from?



Driveshaft:


I have a 2 part driveshaft, one goes straight and out from the cab, then it connects and the second driveshaft goes down. Cutting the length out of the straight across one should allow me to keep everything straight as far as the rear axle goes, there would be no change to the angles. It's going to end up pretty short though, about 4" of tube, ha, and I'll have to bolt on the support piece under the cab which probably won't be fun.



Any tips on figuring out exactly how long that is going to need to be?




Brake line:

This one dawned on me today after I took off the old air-brake tank that covered it up. I'm thinking the best way to go about it is to disconnect it at the end, and after I shorten it, cut the excess length and re-attach.




Any tips on how to do this without getting air in the line? Anything I should do afterwards to make sure my rear brakes are still a go? They're already pretty bad, how do I check for air in the line on them anyways? I should note that this truck at one point had air brakes and where switched back to fluid... maybe they did something off and thats why they barely work, or maybe my brake pads just suck... ideas?





Anything I'm missing or anything that worked well for you? Ideas?


Thanks

 

Stephen

there has been some discussion before on frame cutting... might try the search feature...
I'd recommend a "Z" shaped cut in the frame... it will give you more weld area and be somewhat self supporting... I'd also consider adding a fish plate both inside and outside the frame... here's a reference thread showing what I mean...
https://www.ford-trucks.com/forums/4...e-56-ford.html

the inner and outer reinforcing plates should extend beyond each end of the welds and should be be cut with rounded ends instead of square cut......

I've never done it so this are just some ideas I've picked up reading the posts here... seems like you have anything else pretty much mapped out

later
John

 

Thanks for the link (it lead to one after another after another). I generally search first, but I find when I'm doing something big I seem to do a better job when I talk it out rather than just read, lol.

The Z-cut is the way I am planning, with a fishplate on the back of them too (going beyond the welds).


I'll be sure to post pictures when I do this in case anyone is interested.

 

Would there be any benifit of moving the axle over cutting the frame? I've had a few people on the Hamb say to go that way, just seems like a lot more work, be like 48 rivets to cut, 48 holes to drill, 48 grade 8 bolts... keep in mind for me it's not just the spring perches but the spring stops and whatnot...

 

hey Stephen.
I have a 56 long bed frame too. Mine is from a f250. (i think that is what its called) its really just the long bed f100.
Anyway. I dont really know what you are after with the shortening but if you are just looking to get a frame that will function like a short bed frame then i would suggest just buying a short bed frame and selling your frame.
Someone on here told me that there are frames on here for $100-$300.
I think you could prob. make money as im sure a f600 frame would be worth more than a more common short bed frame.

Plus you can help someone else out and keep that frame origional and you wont have to worry about the structural integrity of the welds.

You could then just box the short frame and it would be just as strong and not have two huge fish plates and welds in the frame.

Im debating this topic back and forth myself. If you do go through with it i would love your input on the subject and PICS!! im sure you of all people could write a great step by step tech article.

Well thats my 2c.
Hope i helped

 

For me, the benefit would be my drilling skills far exceed my welding skills. If you're a competent welder (or know one) and you aren't afraid of cutting and welding the frame, then perhaps that would be easier for you.

I knew a guy that did many, many frame jobs, and he always did it with an angle cut. He explained that not only did it give you more surface area for strength, but it also would have the correct give and flex to move with the frame, and not have stress areas like with z cutting. Apparently, that's the way all the big truck modifying guys do it.

 

Swapping the frame adds a lot of work to the build, though I have considered it before, if I did it be to a newer chassis with the 4x4 parts I would want.

The F-600 is a much bigger beast than the F-100. The steel is almost 1/4" thick. But it will also allow for a lot more weight and stronger axles. It makes the truck one of those "I pity the fool who crashes into it" kinda ordeals, lol. Where you go to see the damage and the paint on the bumper is scuffed and thats about it.

I'm debating just moving the axles forward. Tomorrow I'll try to remove a rivet and see what kind of work it's going to be (there is a part that has to be moved regaurdless of how I shorten the wheel base). It will run me a bit more money for the bolts but it may save me some head-aches. It will also raise the rear up an inch or two, but that might work in my favor if I use the same springs for 4x4 axles (the front goes up with a 4x4 axle)

 

Wayne, thats an interesting thing I hadn't thought of checking, maybe the bolts would be easier...

 

Stephen, the best way that I ever found for removing the frame rivets was to burn the head off with a torch and then blow a hole through the center, they will usually come out easily then. I have shortened and stretched many truck frames in my years of working as a heavy truck mechanic, I always used the angle cut for the joints and plated on the inside. Most people make the mistake of using a heavier metal for the plates, but it will only create stress points because the frame cannot flex there, it will usually break right at the end of the plate. I normally use a piece of frame rail with the flanges cut off for the plates and either cut it with rounded ends or a diamond shape.
I prefer drilling the frame over cutting, but really all depends on application. I'm sure your truck won't see the loads of some I have done. Start with a pilot hole and work your way to the desired size using a slow speed drill and plenty of lube.
If you were closer, I'd say bring the truck over and we'd get started. I would love to see a build like yours.

 

a buddy who's a big truck mech always told me the same process as Jeff explained above. Angled cut, same gauge metal as frame for the fish plate shaped like <==> with all corners cut and finish ground to 1" radius... not personal experience, but from a paid professional who works on big dump trucks all day long.
JML

 

Below is the Ford Fleet Maintenance advisory on modifing frame length - yes it's for new trucks, but it's worth the look.

https://www.fleet.ford.com/truckbbas/non-html/Q18.pdf

 

Hey thats way interesting and helpful, thanks for that.

I think I may just move the bolts forward. I'll still have to cut and weld the end of it by the tailgate, but I like the idea better of not having a cut in the frame. I doubt it will ever even be an issue, but it's a simple matter to avoid, and dispite all the stupid rivets, it will probably be better to just move the axle.

Thanks for the help guys. I'll be sure to post pictures when I start working on it, probably a week till the bed is here...

 

Now that's a good read.
Thanks for sharing.
JML