Drums to disc conversion clarification

[greenone]

Although Ford started installing disc brakes on the F-250 in 1968, they were not factory-installed on the F-100 until 1973...the first year they were standard equipment on all F-100 through F-350 trucks. However, the front disc brake setup on the '73-'79 trucks is a direct bolt-on for Twin I-beam-equipped trucks back to 1965...if the I-beams and spindles are swapped as a pair! The kingpin diameter changed in '75, so all '65-'74 (drum or disc) setups use one size and '75-'79 use another. They are not interchangeable.

So, if I found sprindles, calipers, rotors, etc. from a 1973-4 truck, they would swap out with my 1972 drums without needing the I-beams as well?

[flyboy2610]

I could be reading it wrong, but I believe you need the I-beams as well.
Since you will most probably have to pull the I-beams anyway in order to have the kingpins pressed out, it's no more work to swap them out than you would wind up doing to replace just the spindles.

[FORDification]

It's always HIGHLY suggested to keep the I-beams WITH the spindles as a pair. You're not going to be able to remove the kingpin in a junkyard to JUST get the spindle anyway. The spindle and I-beam will have to be separated with a large hydraulic press (in most cases)....however, in about 30 minutes you can drop the entire front suspension out onto the ground, and then swap the whole assembly into your truck.

However, to answer your question....yes, the kingpin diameter and length would be the same, so they'd mate right up to your existing I-beams, as long as your using parts from the same model (F100/F250/etc.). But there is no advantage or disadvantage to keeping your existing I-beams, other than the work involved with separating them.

[FORDification]

If the previous owner was keeping up with regular kingpin lubrication, you could probably remove it yourself. However, I'd say 98% of the time it was a neglected area, and you could beat all day long with a BFH and not get anywhere. Taking your I-beam/spindle combo to a machine shop and just letting them press out the kingpins with a press is definitely the way to go. It's inexpensive and much easier on the neighbor's ears.

[greenone]

Thanks guys!

I'll need to book mark this post and your responses.

[import600]

OK this is my situation.. ive got a set of spindles from a later late 70's f100.. i won't have the i beams but i'm buying drop i beams for them because i'm lowering the truck anyways.. will this work?

and the spindles and dust shield are the only thing that you can't buy in stores? or will i need more parts off the donor?

[FORDification]

Make sure the manufacturer knows the year and GVW of the donor truck, since I believe there are differences in their product and they'll need to know to ensure they send you beams with the correct kingpin diameter. And I believe you're correct....I can't think of anything else for the disc conversion that you'd need from the donor truck. Just make sure your radius arms aren't rusted out at the back, where the rubber bushings sit at the frame bracket. They do tend to get some rot back there. I'd consider getting the proportioning valve too. Although you can buy these at the auto parts store, they're pretty expensive, and if you can just clean up a good used one you'll save a few bucks.