Steering Knuckle/Spindle Stud Install

[Armymedic]

I picked up a set of knuckle/spindle studs and I haven't been able to find any info about the install. Do you need to drill out the existing knuckle threads in order to press the studs in? If so, do you just go with a 3/8" bit? These are the studs:

 

[NicksTrix]

should be press out old and press in new

 

[Armymedic]

Stock setup uses 3/8" bolts inserted from the spindle into the knuckle. Unless I'm missing something the change to studs would be pressed in through the rear of the knuckle.

 

[thegreatjustino]

If the knuckles you're working with have threaded holes, you won't use the studs. You'll thread into the holes as shown in Armymedic's first photo.

 

[Armymedic]

Were there Bronco versions of the knuckles that used studs rather than bolts? I thought that the studs were a conversion/upgrade.

 

[DirtDonk]

My '71 used studs with nuts and as far as I know they were original.
I could not tell you for certain whether they were threaded in or pressed in, but I think they were pressed in because of the lack of room for bolt heads on the backside in at least some of the holes.
I've had to fix stripped threads before, which makes me think that those were buggered and re-threaded for external bolts at some point in their lives.

If yours are already threaded, do you have the studs in hand to verify the diameter?
That way you could find out for sure if the holes on yours are the right size for press-in studs.
If not you're stuck with bolts unless you can find the correct studs with larger shanks.

I can't say I know every Bronco, just that the ones I worked on were studs with odd-shaped heads in the back.
Are both of those knuckles in the pics yours?

Paul

 

[Armymedic]

The knuckle that's been painted black with the spindle attached is mine. The other is just a random pic I found. I tried screwing the studs into my knuckle but they seem to be just a tad too large (even though they fit into the appropriate size checker at Home Depot). It seems that I would have to grind the threads out of the knuckle or slightly enlarge the hole in order to fit the studs in, I'm just cautious of ruining the knuckle by doing so. Are the studs enough of an improvement to justify doing so? If not I could just stick with the grade 8 bolts.

 

[DirtDonk]

Are the studs enough of an improvement to justify doing so? If not I could just stick with the grade 8 bolts.

I would not think it's worth the trouble. Since the holes are already smaller than even the threaded part of the stud (much less the shank!) then yours never came with anything like that particular stud design and should not be made to work that way.
I'd only do it if it was the last way to do it because the threads were all buggered. And even then I'd use inserts before drilling out that much material.

I'll have to go back and look at mine sometime (I think I still have a drum knuckle) to see if my studs are actually threaded in all the way rather than anything that's pressed in. The random knuckle pic does not look like they have press-in shanks.
The studs pictured originally could be rear wheel studs for all I know.
Wait for others that have messed with theirs recently to chime in. It's actually been quite some time since I looked closely at the backside rather than the front.

Paul

 

[thegreatjustino]

It seems that I would have to grind the threads out of the knuckle or slightly enlarge the hole in order to fit the studs in, I'm just cautious of ruining the knuckle by doing so. Are the studs enough of an improvement to justify doing so?

The studs by the head are splined so they can press into the hole in the knuckle. If you drill out the threads in your current knuckles to try and use the studs, how do you propose to add the splines to the holes in the knuckle so the studs can press in?

No one does this. The knuckles were engineered two different ways from Dana. Use the correct mounting connectors for your style of knuckles.

 

[DirtDonk]

If you drill out the threads in your current knuckles to try and use the studs, how do you propose to add the splines to the holes in the knuckle so the studs can press in?

I agree with everything you said (good to know they came in two flavors) except for this part about the need for creating the splines ahead of time.
You don't usually add splines to match a stud. The stud literally displaces the metal of a smooth hole as it's pressed in. Same for most types I would assume.
Not sure I'm using the proper terminology for what goes on when pressing in splined studs, but you get the gist.

Paul

 

[Armymedic]

The studs by the head are splined so they can press into the hole in the knuckle. If you drill out the threads in your current knuckles to try and use the studs, how do you propose to add the splines to the holes in the knuckle so the studs can press in?

No one does this. The knuckles were engineered two different ways from Dana. Use the correct mounting connectors for your style of knuckles.

I hadn't thought of that. I'm not determined to attempt this if it's impractical or of no real benefit, which seems to be the case. I just wasn't aware that there were two styles of knuckle, but that explains why I wasn't able to find any good info on the switch. Thanks to you and DirtDonk for helping clear it up for me.

 

[Jedeka]

There should be a spec somewhere to tell you what size the holes need to be to press in the studs. My 74 has the 6 threaded bolt holes in the knuckle. The disc brake knuckles from the 78-79 Bronco have the 5 studs.