Confusion on disc brake swap

[Bryan_Tenn]

what I'm trying to understand is, if its just .0001 (sorry bout that before) difference & either will fit, then why does everyone make such a big deal about it being a MUST to get the i-beams too if you use 75-79 spindles???

Basically Bobby is saying I can use my I-beams with 75-79 spindles. I just cant get a clear understanding on which kingpins will be easier to use. It just creates a lot of confusion.

[Bryan_Tenn]

can anyone else chime in? I didnt really get a definite on my original question I don't guess

Can I use the smaller king pin set with my 72 I-beams & 76 spindles with no machining or problems? By what Bobby said it sounds like I can

[BobbyFord]

New bushings will have to be sized, anyway. I don't understand where you're confused.

[Bryan_Tenn]

New bushings will have to be sized, anyway. I don't understand where you're confused.

I dont guess I know what "sized" means. I planned on cleaning the bores up with some emery cloth & pressing them in the spindles, then lubing & driving the knig pins in. What exactly needs to be done, or what is sizing?

[BobbyFord]

Scroll back. Ultraranger explained it, with pictures.
Bushings need to be sized with about .001 clearance to the king pin.
Buy a 1972 king pin kit (Moog 8524B) and have them sized at an engine shop. It's really that easy.

[sargentrs]

What Bobby and Steve say is the whole deal. The bushing spec is .001" diameter ID larger than the king pin OD. No matter what the king pin OD is. Doesn't matter which king pin you're using as long as the ID of the bushing is .001" larger than the OD of the king pin. If your original king pins are .8592" and your bushing ID is .8602", you are within spec. If you use the .8593" pins in the same bushing you are .0001" tighter fit than necessary but that's not really a big concern. The bushing will wear down to that pretty quick with the possibility of damage to the king pin minimal to non-existent. What everyone is trying to tell you is that you need to check/verify/rework your bushing to insure they are .001" larger than whatever king pin you use. If they are the original bushings, they've probably already worn such that the .8593" pin will just take up some of the slack that's already there, not necessarily a bad thing. If you put the .8592" pin in, it probably won't even be noticeable. My advice would be to attempt to assemble it with the .8593" pin. If it slides in easily or with the lightest pressure, use it. If you can't push it in that way, it's too big. Do the same with the .8592" pin. If it feels sloppy or you can wiggle the spindle at all, it's too loose and you should put new bushings in anyway. I had mine done at a local machine shop when I swapped on my '74 disc spindles. I even held the machining lubricant hose while he reamed them and helped him assemble them. When they went together, it was the sweetest, tightest slip fit I've ever experienced. They wouldn't fall through on their own but you could push them in with one thumb pressure and there was zero slack that a human can feel with their fingers. Very professional work. It cost me $200 for the set, installed and machined, and included bead blasting and painting. I supplied the king pin kit. If your driving her now with sloppy king pin bushings, the larger pin is better than the smaller pin. However, no better time to do it right than right now while you have them apart and not have to mess with them for another 40 years or so.

[Bryan_Tenn]

ok sarge, thats clearer.

I plan on installing new bushings & king pins. I planned on getting the smaller ones for the 72.

Actually, the king pins out of the 76 are fine, I havent taken them out of my 72 yet, is there anybody that makes just a bushing set without the pins?

http://www.oreillyauto.com/site/c/detai ... word=8524b

here is the link for Moogs #8524b at O'Reilly for the 72. I worked at O'Reilly for years & can get a little better deal than the $74, but I see a lot on ebay, even from JEGS for less than $50 with free shipping so thats where I will be getting them or make O'Reilly match it I like getting things from my local parts store for ease of return if somethings wrong & keeping money in the community but $25 is a BIG difference!

http://www.ebay.com/sch/i.html?_from=R4 ... g&_sacat=0

[ultraranger]

ok sarge, thats clearer.

I plan on installing new bushings & king pins. I planned on getting the smaller ones for the 72.

Actually, the king pins out of the 76 are fine, I havent taken them out of my 72 yet, is there anybody that makes just a bushing set without the pins?

http://www.oreillyauto.com/site/c/detai ... word=8524b

here is the link for Moogs #8524b at O'Reilly for the 72. I worked at O'Reilly for years & can get a little better deal than the $74, but I see a lot on ebay, even from JEGS for less than $50 with free shipping so thats where I will be getting them or make O'Reilly match it I like getting things from my local parts store for ease of return if somethings wrong & keeping money in the community but $25 is a BIG difference!

http://www.ebay.com/sch/i.html?_from=R4 ... g&_sacat=0

I don't know if you can get just the metal bushings(?). If you're replacing components, it's better to replace the bushings and pins as a (new) matched set.

I would also advise not to hammer the bushings into the spindle bores. This will mushroom the lip of the bushings.

I initially tried to draw the bushings in with a piece of all-thread, some washers and an 11/16" Snap-On deep well socket. That didn't work so well for me so, I put the spindles in my 20-ton press and it smoothly pressed the bushings right into the bores.

[BobbyFord]

King pin set is $46 from Summit.

[Bryan_Tenn]

King pin set is $46 from Summit.

when I punch that part# in 8524B on ebay it comes up for jegs but not Summit

Do they use a different#? Was just getting ready to order but Jegs has it as an item that wont be delivered until 15th of January. Someone else in CA has it will be here by the 31st.

[Bryan_Tenn]

summit just has a mog prefix. Anyway, they must just not be selling it on ebay. I'll just order from their website