How I lowered a 1962 F-100 with an axle flip (1961-1964 I-Beam)

**UPDATE**

This will be not only the thread outlining the lowering of this F-100 using primarily factory components, but also the subsequent build into a land speed competition "production pickup". When I'm done with the chassis, and some other periferal work, it will head back down to Tim's (mctim64) place to get the cage, a paint job, and final tech requirements installed, as well as a ferocious stroker Y-block mill.

Regarding the lowering, let me just say that the search function is your friend regardless if you're a FNG or have been around from the beginning. I had found the following threads to use as reference, you might like them as well:

http://jalopyjournal.com/forum/showthread.php?t=153730&highlight=how+lowered

http://jalopyjournal.com/forum/showthread.php?t=398754&highlight=64+lowering

Here's the beginning. A solid, rust-free CA truck that had been holding down a tomato garden. The goal is a 6-7" drop in front, and a fairly aggressive rake.

For those of you that skip to the end of the story, here's where we are right now. All I ask is that you read before you ask a lame question that's already been answered. Lot's of helpful information in the following posts, hopefully it will help many of you with your projects. While this is a '62, most of the information and techniques will be very similar, if not typical to a '57-64 F-100 as well.


Keep in mind there are a few things that you'll probably see that aren't advisable for daily use, but that's not what we're doing here. This is just a small installment of a production class pickup for land speed racing that Tim McMaster and I are building. It goes without saying that if anyone has questions about what I did here, or plan to do, just ask. No secrets here, and I'm happy to share.

 

Here's where we start. Short block needs to stay for checking pan clearance, and eventual steering box clearance (I will be moving the box upward and forward to match new axle location).

As a notch for axle clearance is more than likely, boxing plates will be required to maintain strength. I decided that tying them into the existing bracing would be the cleanest approach. Here you can see where I marked to trim some of the existing bracing for a straight butt joint.

Then checked the fit, and also marked for the slight cureved cut at the bottom of the frame. I used 3/16" plate:

Cut and tacked:

Welded and ground:

Same on the other side:

 

Looks solid....nice job ! ! !

 

As I go to work on the axle, here are the plates that I had made for the saddles that will be located underneath the I-beam. I only need 2 for the finished install, but I needed 4 for the mock-up process (you'll see):

Started with the axle upside down, level and sitting squarely on stands:

Cleaned the areas that will be welded:

I used long bolts to locate the aforementioned plates, and threaded nuts underneath the plate to build in and suport some additional caster angle for high-speed stability. You'll note that there's some space between the plate and the I-beam. With the 10 degrees of additional caster built in, the tie rod to leaf spring clearance was a concern, and it was an opportunity to safe guard against interference. Maintaining stock caster angle would make this a non-issue.

Here's the plate located on the screws, before tacking it in place:

 

Here's a couple shots of what was involved with boxing the plates in. Not a simple box...the caster and plate location did complicate things a bit. You can also see the added distance between the plate and the I-beam in this shot. A street truck would be more straighforward. The boxing plates began life as 2" x 4" x .125" rectangle tube with one side of the rectangle removed. The dimension worked well to surround the bolts:



Both front plates tacked in place (though not shown, similar boxing was installed on the rear of the I-beam):

I mounted the axle one last time to verify the axle centerline location, particularly since the added caster moves the centerline to the rear.

Then, it was time to drop the leaf springs, and set up the axle on top. Note that I used the other 2 plates, and the 1/2" bolts to mock it up. The custom u-bolts have not yet arrived from the spring shop:

 

Anyone who has lowered a 1957-64 F-100, or a 1955-66 Chevy/GMC is probably familiar with this site. I will be moving the axle c/l forward 2 1/2". This will help with stability, weight distribution, etc. If it were no benefit, I'd still do it simply because it will look much better than this. The factory didn't do a very good job of locating the axle centerline, IMHO:


This is about where I finished off the weekend. There will be more to come as I have to finish welding the axle perch/mount, determine the final location and depth of the notches and install them, as well as move the steering box up approximately 6", and forward 2 1/2". This will cure any potential issues with bump steer, as the stock geometry will be maintained. If you've made it this far without posting a response already, that's probably what you were wondering about, right?

Here are a couple of shots of clearances as they stand right now. Keep in mind the weight of the front clip and a complete wet engine will drop the front another 1 1/4". I'll be fabricating new shock mounts (upper & lower to utilize shorty gas shocks) and installing notches and bump-stops:

May not look like it, but there's about 3" to the pan. This will increase when the axle moves forward, as the pan is sloped from front to rear:


More to come in the coming weekends, thanks for looking.

Todd

 

A couple final parting shots...keep in mind the after will be dropping another 1 - 1 1/2" after the engine is complete, the front clip is reinstalled, and the shorter front tires are installed.


To this:


Todd

 

Thanks Chris...wouldn't be hard to do on Gumby, either

 

Looks great TODD. I came so close to doing this on my '64. This method sure gets them nice and low on the cheap. I was just about to ask you about the bumpsteer issue but then I saw you had a plan to address it.

And to everyone else, tune in a few days from now for a complete write up (with tons of pics) on how I put a Jag IFS in mine instead!

 

You're going for land speed with steel welded to cast? I hope they have tech inspectors there.

 

Look forward to your thread Matt...

I would have MUCH rather put a MII in this, but for the class it will complete in, is has to use the factory components. Obviously things can be rearranged, but non-factory IFS is a no-go.

 

The axle is forged.

 

You posted this concern on loddadyo's thread (post #27) also:

They were forged then, they are forged now. These aren't riding lawn mower axles.

But to answer your questions, yes I am welding to the I-beam, yes we are going racing with it, and I hope there are tech insepctors there also.

Todd

 

So you wouldn't do this to something you drive daily? Why not?

Not attacking anyone/anything, I'm just curious!

 

So cool. I was entertaining ideas of a setup like that when I had a '60 F100, but I never got around to it. =/

 

What is it with everyone assuming the axles are cast. I have had this on my truck ( same idea just not executed the same way ) for over 5 years now. I drove back and forth to wyoming from colorado 300+ miles, one way, about 35 times. I was in school and the family stayed in colorado springs. So daily it should be fine. Check for bumpsteer though. I had to z my link farther to compensate for it being dropped. Great tech!

 

I would do it on a daily--no concerns about safety or longevity. But I will be allowing less suspension travel on this than I'd want to live with everyday, and I wouldn't build in so much caster. I was just trying to make a bit of a disclaimer in the event that someone wanted to replicate the approach...

 

Thanks!

I'll be moving the steering box up and forward to correlate with the revised axle location.

A lot of folks think that you don't have to address the issue (pitman arm/drag link alignment) with dropped axles/springs. Not so! It's all about the geometry.

Todd

 

This was covered here.
http://www.jalopyjournal.com/forum/showthread.php?t=153730

Great job Todd!

 

I think you were reading my mind.

P.S. Really Nice Work.

 

I can be there in a couple of hours...

 

Appreciate the comments guys!

I can only imagine how excited Corinne will be if another F-100 shows up...though I do have some extras for another flip...hmmm.

Todd

 

Great article and pics! Subscribed.

 

That is looking good, and a lot to learn from. Keep us posted.

I do have a question about the added caster. That question being what do you gain? Not a criticism, curiosity.

 

To over-simplify it, leaning the king pin angle back makes it "want" to track straight. The closer to vertical the caster is, the easier it is to turn but it also "wants" to wander.

I'm certain that someone else could explain it far better than I, and I probably could if I cracked my old books onthe subject...

 

Where are you getting your new spring bolts from? And what was the cost on them.. I am really needing to do this to my 64 asap.....

 

Great job and great pics! You do some amazing work!

 

Seems you have this planned out pretty well. Way to go, nice amount of drop on the front!

 

Firstly, Todd nice job on your workmanship. I've been doing a '62 unibody and have not heard of moving the axle forward or even had it suggested. Could you maybe shed a bit of light on that??. I have a Sid's dropped axle in mine. Also, I have a stock 1962 ford axle with the plates welded and flipped by a friend's shop if anyone needs one. thanks, cheers

 

Was that ten degrees total positive caster?