Rusty Hope Disc Brake Conversion

[Jim Shepard]

I realized I was bordering on highjacking 53Windsor’s thread (or maybe actually did…). Anyway I had another comment about this conversion and an issue I have not seen addressed yet: the castle nut/cotter pin issue. Charlie mentions in his instructions that as result of the conversion the castle nut may not fit deep enough to align with the hole in the spindle and thus not allow the cotter pin to be installed properly. Apparently this does not happen on all applications. It did on mine. He advises several ways to deal with it, none of which seemed appropriate (such as reversing the castle nut, essentially installing it backwards).

 

Now I understand that many, if not all, folks doing this conversion probably followed this advice and have had no problems or catastrophes. However, since I was dealing with my own comfort level, I decided on a different approach. I took the disc/hub to a machine shop and had them reem-out the inside (the part that goes over the spindle) to a depth that allowed the nut to screw in far enough to allow all of the threads to engage and the cotter pin to drop in. If I remember it was an additional 5/16”. Just a thought…

Edited August 30 by Jim Shepard

[Jim Shepard]

Don’t get impression I’m trash-talking Rusty Hope’s product. Thankfully he’s one of the few actually producing products for our old MOPARS. I would heartily recommend him to anyone. It’s a quality product and it sure as heck stops my truck on a dime!

[Plymouthy Adams]

I addressed the issue quickly and easily in a manner that it can be done at home and also to suit me by just elongating the cotter pin hole by inserting a drill bit into the original hole holding it in place with the nut and drill another hole in front to that one using the inserted bit as a hardened pin to ensure/guide the bit ahead of the original hole.  When the hole is drilled, removing the nut acts as a chip breaker.  You can drill part way in from the top and then part way in from the bottom as the spindle may have a small center bore here that could cause for bit to wander and break, center punch if drill from below also.  The key slot also sets up you left and right edges and prevent the bit from wandering.  Then with a jeweler's file I dressed the hole to a slot.  

 

 

 

 

Edited August 30 by Plymouthy Adams

[Los_Control]

That sounds like a perfect way to correct it.

 

I think that the castle nut has a very important role in the front wheels.

The actual purpose of it is to hold the front wheels on the car .... it actually sets the pre load on the front wheel bearings ....  you snug them up to where there is drag .... then you back it off to allow free movement with no drag or wobble on the bearings.

 

This is not a nut you torque down to 40 pounds .... It is something you adjust freely then use a cotter key to hold it in place.

 

While it sounds jacked up, imho if the nut has enough threads threaded to get on the spindle, the nut does not care which direction it is threaded on ..... the cotter key just keeps the loose nut from backing off.

 

So your way is fine, I think Charlie way is fine also ..... such a minor detail not worth worrying about.

[Plymouthy Adams]

If I recall correctly, either on as normal or facing the castle nut to the bearing the hole was off enough in either case the cotter pin would not effectively slip in either way.  But is seems with each install, each installer faces or finds an issue contrary if only in minute detail to that of anther person.  The above post was just a manner I corrected mine and just a suggestion this may work for you.  Others have found their own respective cure and that sits well with me also.  Same crazy cat carved with a different knife.

[Sniper]

I did cover this exact issue in my write of the swap I did.

 

 

[Plymouthy Adams]

mine above is a repeat, seems few folks search the forums regardless of the fact it is quicker and easier to do with immediate results verse waiting to see if anyone cares to repeat themselves and even when given various means to address the situation, months later it often is readdressed.  

Edited August 31 by Plymouthy Adams