Brake Drum Question

[jac04]

I'm putting new front drums on my Lightweight, which has 11" drums, part number 576973 (these are the later style with the bigger stud holes).

I noticed that the machining of the new Proline drums seems to be unusual on the surface where the wheel mounts. The machining of the surface actually takes a step out - just outboard of the stud holes. This means that the wheel will sit on this surface ( labeled "high")when mounted and will have to flex as the lug nuts are tightened to contact the inboard surface (labeled "low"). This doesn't seem right to me. Any comments?

I have looked up p/n 576973 on lrseries.com, and their picture looks just like what I have, so I may be OK. See http://www.lrseries.com/shop/product/listing/1585/576973-LWB-BRAKE-DRUM-SERIES-3.html?search=576973&page=1
Now, I have also looked at the earlier style drums (p/n 516599) with the small stud holes. This is apparently what was on my vehicle, but someone drilled out the stud holes to make them fit. On the earlier style drums the inboard surface is higher than the outboard surface, which is opposite of what the new drums are . However, this makes more sense to me.

Anyone out there have any 11" drums they can check out?

http://i79.photobucket.com/albums/j126/jac04/000_1680.jpg

[brucejohn]

I have 8 11" drums; 4 from an early 60's S11A 109, 4 from an 82 S111 109. All the old drums have a flat face with no step either way. Unfortunately, all 8 drums are over size and cannot be turned; I should be receiving my Proline drums from our hosts in a couple of weeks. I'll let you know what I receive, if you'd like.

EDIT[ I noticed that the old drums have three set screw holes and a threaded 'push off' hole]

[brucejohn]

What is the diameter of the inner surface on the new drums? The flat 'contact' surface on the nine old wheels I have appears to be 8-5/8" to 8-3/4".

[jac04]

brucejohn-
The recessed surface is 7-3/4" diameter. The contact diameter on my new wheels is the same as your old wheels - 8-3/4" diameter.

I'll be contacting RN tomorrow regarding this, but please let me know if the drums you get are the same as mine.

[brucejohn]

Jac04...
Will do.
...bj

[brucejohn]

jac04...
I received two brake drums today, two back ordered. They look to be the same as yours. They came in Allmakes 4x4 boxes (same brand as the parabolics I received from our hosts).

What did RN have to say when you contacted them?

[jac04]

Thanks for the feedback brucejohn. I also have the Allmakes parabolics, and the rear of my vehicle seems WAY high. Let me know how yours are once they are installed - I'm curious.



What did RN have to say when you contacted them?
I sent them a nice e-mail with pictures 4 days ago, and a reminder 2 days ago, but they don't seem to return e-mails (even from someone who has spent about $15k over the last year with them). :confused:

[Les Parker]

Here is a pic of the Genuine Landrover 11" brake drum.
The variation of the surfaces from inner to outer is negligable (may be 1mm).
Please advise if this would work better for you.

Apologies in the delay of reply, we have just recieved some new Genuine stock

[jac04]

Les-
Which surface is higher?
Either way, the Genuine drums would work much better. What do I need to do to get them sent to me?
Thanks,
Jeff

[Nium]

I'm kinda wondering why the face of the brake drum, side that mates up to the wheel, isn't flat. If you look at this pic of a used IIA 109 drum (for sale in "Clearance Outlet") here on RN...

http://www.roversnorth.com/store/p-16627-brake-drum-series-iia-109.aspx

You can tell that there is no step down from the outside diamter to the inside diameter on the outside of the drum at the wheel mating surface.

Another question that brings up. Why do all new drums just have the one set screw hole instead of the original 3?

[brucejohn]

Nium and I are wondering the same things, Les? Any inspiration?

[Les Parker]

Nium,

This brake drum also has a slight step as described on the new Series III brake drum.
There is only a real need for 1 brake drum locating screw, as the drum is held onto the hub by the wheel and wheel nuts.

Hope this helps