69 2000 Brake Drum Holes

[NorCalMark]

Hey All:

Working on my new old 69 2000 roadster. This site has been great help so far, thanks!

Adding longer wheel studs. Has Enkei rims and there was not a lot of purchase with the lug nuts. While pulling the drums to inspect, I found the left had two holes, per pic below. One appears to have been plugged, and I found a corresponding lug of metal floating around. Looks like the plug may have been long and knocked off. All looks good inside the hub, shoes, cylinder, etc. Any thoughts on what is going on here? Should i just drill out the remainder of the plug and re-assemble? Thanks for any guidance.

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[notoptoy]

That chunk of metal look like they may be part of the brake adjuster? I don't recall ever seeing plugs in the drums before.

[NorCalMark]

I thought it might be the adjuster as well, but they are all in place. Weird. Thanks for the idea

[Nissanman]

I have noticed that the finned alloy brake drums fitted to the Z series cars have that hole.
The factory fits a lead weight in there to aid with balancing the drum I'm guessing
I have several of these in storage and they all have it.

[notoptoy]

So Nissanman, are you suggesting he has incorrect drums on his Roadster? That would make sense to me.

[Nissanman]

Well, I'm reasonably sure they are Z drums if true Roadster drums weren't fitted with that hole and weight.
As long as they fit OK I can't see any issues with using them.
I have a some of them that I was going to fit to my '65 one day: haven't even trial fitted them so I am not able to say if they work or not.

[todd lorber]

The Z drums have a hole in the front because the brake adjuster is accessed via that hole. I'm aware of this because when I bought VTO wheels for my Z, I drilled a new hole on the drum because the spoke of the wheel covered the original hole and I was unable to adjust the rear brakes without pulling the wheel.
As I recall, the Roadster brakes are adjusted via a square shaft bolt on the inside of the wheel.

[unklpat]

I have 2 spare drums, no holes. No holes in the ones on my 68 either. Pat

[NorCalMark]

Hmmm, thanks all for the input. I have the car on jacks and will check. A separate 311 Post states:

“ The Z drum has a 12mm[0.472"] stud hole and the standard Roadster studs are 7/16"[0.437" or 11.09mm].
That means there is a "slop" factor which can cause the drum to be eccentric to the hub

The post goes on to talk about needing an adapter To use these hubs. Which raises a whole new set of questions. Will let you know what I find.

[NorCalMark]

Well, pulled both drums. One has the unusual holes, one does not. Stud holes in both drums measure 11.6mm. So they would never accept a 12mm stud, I tried one. When drums installed on axle, there is no slop in the drums. Seems it is not a Z drum. I did see there is a newly manufactured drum on one vendor site that has an “adjuster access” hole like the Z hubs. Strange. At this point I do not see an issue with using these drums. Any thoughts appreciated

[notoptoy]

What is the diameter of the drums? Are they the same side to side if they are different drums?

[NorCalMark]

Both drums measure out the same in every way. 230mm interior dia., 54mm interior depth, same overall width, same stud hole diameters of 11.6mm. I would be interested in knowing if these measurements match known 69 Roadster drum specs. And thanks Notoptoy for your interest