Disc Conversion Knuckle ID Question

[JeepGuy]

Hello.

Typical story here...;D bought these parts awhile ago and my project has just been sitting. Finally getting back at it.

I believe these are F250 knuckles but I'm not positive. Can anybody id them with a typical year range so I know what I'm dealing with?

If they are, does that mean I can buy any of the various Ford disc brake replacement parts? I have these knuckles, Caliber brackets, Spindles, and a set of old calipers, but I need the Disc and Hubs, bearings, seals, etc...

 

[jamesroney]

Hello.

Typical story here...;D bought these parts awhile ago and my project has just been sitting. Finally getting back at it.

I believe these are F250 knuckles but I'm not positive. Can anybody id them with a typical year range so I know what I'm dealing with?

If they are, does that mean I can buy any of the various Ford disc brake replacement parts? I have these knuckles, Caliber brackets, Spindles, and a set of old calipers, but I need the Disc and Hubs, bearings, seals, etc...

C37917 and C37918 are 76-77 Bronco knuckles. Yes, you can use the Ford replacement parts.

 

[DirtDonk]

You'll need a new tie-rod though.
We sell a conversion tie-rod that will fit with your early style drag link (https://www.wildhorses4x4.com/product/Tie_Rod_2way_Adjustable_7677yr/Custom_tie_rods) and is wider than a stock '66-'75 tie rod, and has the smaller tapered studs for the smaller holes in your new steering arms.

And if you use those knuckles you'll need to be wary of wheels with more than 3 5/8" backspacing.

Paul

 

[JeepGuy]

C37917 and C37918 are 76-77 Bronco knuckles. Yes, you can use the Ford replacement parts.

You'll need a new tie-rod though.
We sell a conversion tie-rod that will fit with your early style drag link (https://www.wildhorses4x4.com/product/Tie_Rod_2way_Adjustable_7677yr/Custom_tie_rods) and is wider than a stock '66-'75 tie rod, and has the smaller tapered studs for the smaller holes in your new steering arms.

And if you use those knuckles you'll need to be wary of wheels with more than 3 5/8" backspacing.

Paul

Thanks for the info.

So good thing is they are ford parts with everything available. Bad thing is clearance issues with tie-rods.

I bought a 1 ton tie rod set up and was going to drill out the arms for the larger tie rods. Is that going to be a problem if I go over the knuckle instead of under the knuckle?

 

[DirtDonk]

Just gave a few opinions but it won't let me post it. I'll try to PM you and maybe it will let you put it up. If not, at least you'll have some additional thoughts on the subject.

Paul

 

[DirtDonk]

I'm going to try again with a trimmed down version.
Apparently something in how I set up some replies has some imbedded code that sends me to a "forbidden action" page instead. Been down this road before and trying to narrow it down.


The '76 and '77 EB knuckles have smaller steering arms overall. Not a ton of meat around the hole already, so reverse tapering and making the holes bigger as well, has had some of us worried about potential weaknesses. None of which have turned up, that I know of. But that are there nevertheless.
While you can usually get away with simply tapering down from the top and leaving the lower portion open (kind of an hourglass shape so to speak) you might want to use the best-practice of weld filling the hole at least partially before re-drilling for the TRO.

Just a suggestion. I'm neither a metallurgist or welder or engineer, but adding some material makes sense to me.


Let's see if this condensed version works...

Paul

 

[JeepGuy]

I'm going to try again with a trimmed down version.
Apparently something in how I set up some replies has some imbedded code that sends me to a "forbidden action" page instead. Been down this road before and trying to narrow it down.


The '76 and '77 EB knuckles have smaller steering arms overall. Not a ton of meat around the hole already, so reverse tapering and making the holes bigger as well, has had some of us worried about potential weaknesses. None of which have turned up, that I know of. But that are there nevertheless.
While you can usually get away with simply tapering down from the top and leaving the lower portion open (kind of an hourglass shape so to speak) you might want to use the best-practice of weld filling the hole at least partially before re-drilling for the TRO.

Just a suggestion. I'm neither a metallurgist or welder or engineer, but adding some material makes sense to me.


Let's see if this condensed version works...

Paul

Got your PM and this reply. Thank you for the info. Looks like I might be going a different direction as it's currently on 35's. They worked fine with drums.

If I'm reading right, I can grind down those knuckles and do the Chevy parts outer conversion from there to run the discs up front.

It's always something... lol.

 

[DirtDonk]

No, you grind down stock Bronco drum brake knuckles. There is nothing about the disc-brake knuckles that will work with the GM disc brake parts in the kits.

The main reason is that the spindles for the disc kits are 6-bolt just like the Ford drum brake setups. Yours are 5-bolt so are not compatible.
But the ones currently on your Bronco (if you have stock ones?) are what is used. So if you have those, you're good to go there.

And the disc knuckles are still worth some money to someone that can utilize the stock disc brake setup.

Paul

 

[JeepGuy]

No, you grind down stock Bronco drum brake knuckles. There is nothing about the disc-brake knuckles that will work with the GM disc brake parts in the kits.

The main reason is that the spindles for the disc kits are 6-bolt just like the Ford drum brake setups. Yours are 5-bolt so are not compatible.
But the ones currently on your Bronco (if you have stock ones?) are what is used. So if you have those, you're good to go there.

And the disc knuckles are still worth some money to someone that can utilize the stock disc brake setup.

Paul

Thanks for your patience. Just getting back into this whole rebuild so remembering what was bought with what intention is a bit of a challenge.

So here is my thought process thus far. Re-sell the front knuckles, caliper brackets, and spindles for the 76 -77 set up.

Purchase this : https://www.wildhorses4x4.com/product/Front_Disc_Kit/Bronco_Disc_Brake_Kits

And then just grind my knuckles that are already on there to make the kit work. Looks like either way I'm breaking down the outers and drilling the knuckles for the one ton tie rod conversion.

 

[DirtDonk]

Correct.
And as far as TRO, the only option other than re-drilling from the top would be to find some GM or the even rarer Jeep Dana 44 knuckles that are already drilled for TRO from the factory.
And hope that they work with disc brakes!

I don't know all the compatibilities, but it seems more sensible to just drill out the knuckles that you know will work with all the other stuff.

Are you doing TRO for a specific reason, or just because? Reason I ask is that you need to factor in all the other stuff in the system, such as keeping the drag link parallel to the track bar, clearance for the lower trackbar bolt/stud (because the big tie-rod will hit it at full turn), plus the overall angle of things.
It's all a system and many things have to work with many others. And TRO is rarely a bolt-n-go proposition to get it right.
Things such as:
1. drop pitman arm or not? And if so, which one?
2. Track bar riser (almost always) or drop (or both)?
3. Tie-rod clearance with the wheels (should not be a big issue with the stock knuckles I don't think)
4. Which steering box (effects pitman arm height)

You know... All the fun stuff like that.

Paul

 

[JeepGuy]

Correct.
And as far as TRO, the only option other than re-drilling from the top would be to find some GM or the even rarer Jeep Dana 44 knuckles that are already drilled for TRO from the factory.
And hope that they work with disc brakes!

I don't know all the compatibilities, but it seems more sensible to just drill out the knuckles that you know will work with all the other stuff.

Are you doing TRO for a specific reason, or just because? Reason I ask is that you need to factor in all the other stuff in the system, such as keeping the drag link parallel to the track bar, clearance for the lower trackbar bolt/stud (because the big tie-rod will hit it at full turn), plus the overall angle of things.
It's all a system and many things have to work with many others. And TRO is rarely a bolt-n-go proposition to get it right.
Things such as:
1. drop pitman arm or not? And if so, which one?
2. Track bar riser (almost always) or drop (or both)?
3. Tie-rod clearance with the wheels (should not be a big issue with the stock knuckles I don't think)
4. Which steering box (effects pitman arm height)

You know... All the fun stuff like that.

Paul

Lol Yup, always something.

4x4x2 steering box. Already have the Track Bar riser installed. 3 1/2 inch suspension lift (one of your kits). Not sure on the drop pitman arm yet, I have a straight one that I was going to try first.

Not completely sold on going Tie rod over, but I would like to step it up to the one tons due to the factory one already being bent, and I already purchased the replacement. Under or over really isn't that big a deal to me as I'm not planning or, nor did I get too extreme with wheeling the Bronco. Moderate to difficult trails, yes, but not king of the hammers type stuff.

 

[DirtDonk]

Ok, sounds like a plan then. The flat pitman arm is probably going to be the one with that combo I would think.
And since you have the riser, I would still seriously consider the TRO, but I might be very tempted to try it both ways. Maybe not permanently, but mock it up in both conditions before committing to drilling and tapering. This lets you know where the draglink will fall in the scheme of things.
Mocking up will let you know how things are going to line up with the existing riser.

Your things to look for (sounds like you already know, but might as well run them down) are:
1. The drag link and track bar should be as parallel as possible.
2. They should be at as low of an overall angle as possible.
3. They should be as close to the same length as possible (your draglink is naturally longer in this scenario, but it's something to keep track of).
4. And they should travel in the same plane if possible. In other words, the less of a parallelogram they form, the better.

With a riser and with the tie-rod in the normal under orientation, it's hard not to make a parallelogram. But keeping it to a minimum is a big help.
Which is why I think TRO might end up being your best bet with the parts you've mentioned.

But mocking up is your friend here. So take that little extra time to do it. Even if you're the impatient kind that can see the light at the end of the tunnel and really wants to get to driving it again!;D

Paul