Alum. drums

[Alan Roehrich]

Hard anodizing doesn't necessarily have a lot of color, it usually darkens the surface slightly.

The scarf cut Teflon seals work fine. They seal better than you'd think.

There's nothing wrong with the chrome sealing rings. I've used them, and still do. I also use the scarf cut Teflon sealing rings.

[buzzinhalfdozen]

I guess most of my confusion on the hard anodized is I've been lead to believe it is VERY hard and durable, not what I'm seeing on this drum. I wouldn't expect the teflon seals to even damage a bare Alum. drum. Maybe I expect too much. Joe

[Tom Goldman]

Joe , Teflon can wear into most everything given enough time.
I just replaced a PG ringless input shaft because the teflon rings in the stator tube wore into the hardened Vasco steel shaft!.
Those rings do not turn, they ride stationary on the spinning shaft.
Tom

[ss3011]

The reason steel rings spin with the drum is because they have a thicker width which creates a higher force radially and overcomes the frictionally force created by oil pressure pushing the seals against the groove sides. The teflon seals are narrower so the force balance keeps the seal stationary in the groove and slips on the id of the drum. The teflon has a fiberglas filler material and that is what wears into the aluminum bore. One thing to keep in mind is aluminum drum expands alot more than cast iron drum and the steel seals typically have a clasp in the gap of the seal. If the bore wears too much or the aluminum drum get too hot , the clasp could prevent the seal from growing to keep the seal in contact with the bore. That creates a huge leak. Recommend a scarf cut teflon seal, and just live with the wear.

[Mike Fuller]

Joe if you want a permant fix for this , I can insert a steel sleeve in the drum. I have done this for a number of racers and it cures the problem once and for all.