Alum. drums

[buzzinhalfdozen]

Can you use metal seals on an alum. drum? Trans is a T-350 direct clutch drum. Thanks Joe

[sugar1366]

You should always use teflon seals on an aluminum drum. Metal rings will wear grooves into the ID of the drum. The Transtar part # is 44175BT. If you don't have an acct with them, any local transmission shop should be able to order them for you. If not, you can get them from Paul at Turbo-Action (904-741-4850).

Eddie Bolton

[Alan Roehrich]

Originally Posted by buzzinhalfdozen

Can you use metal seals on an alum. drum? Trans is a T-350 direct clutch drum. Thanks Joe

You can, but it is not a good idea. And you should never use a regular "rebuilders" type metal seal. The aftermarket companies, at least at one time, made moly faced sealing rings. Those "could" be used. But I'd advise you to use scarf cut Teflon seals. Usually aftermarket companies sell the seals for $15 or so for the set.

You may even find some in a TH350C/TH250C kit, as those late model lockup units (that's what the "C" denotes) often had the blue Teflon seals.

A good transmission parts house, like "Whatever It Takes", will have those kits fairly cheap (called a "short ring" kit, or "paper, rubber, rings, and seals" kit, or "overhaul" kit), maybe $20-$40 or so.

[Tom Goldman]

You have to remember the ring is supposed to be stationary in the drum and rotates in the ring land not the drum.
If the unit end play is held to a minimum the actual movement ot the ring within the drum bore is minimal. ...If line pressure is not excessive there should be minimal wear issues with a iron ring. .. I'd use the ATI chrome rings.

I've got several customers with 727's with aluminum drums using ATI chrome rings for years with no wear.
Many more PG'S also with chrome rings , altho ATI now makes their aluminum drum with a steer bore insert to hold up to racers using high line pressures.
I have seen wear caused by teflon rings in iron drums ,and pump ring lands when line pressure is very high. .
Tom

[Jim Kaekel]

Having literally grown up in a auto transmission shop, I would definitely use Teflon rings when using an aluminum drum. Even when using Teflon, the drum will still wear on the sealing surface, but not as great as if you were using chrome rings. The life of the sealing ring bore will last longer if the drum has been hardcoat anodized, but even that is not a cure all. A friend repaired an aluminum drum for me that was wore heavily by installing a steel sleeve, which eliminated the problem entirely. Like one of the other fellows said, I believe ATI now sells an aluminum drum for the Powerglide with a steel sleeve. Just my .02.

[buzzinhalfdozen]

Oh come on guys... I understand that everyone has their own ways of doing things and beliefs of what the best way of doing things are, this drum already has grooves in it was supposedly hard anodized however can see bare alum. at seal surface. The teflon rings just seem to fall thru the drum, the steel ones you have to push thru, was thinking of having drum honed smooth and installing steel rings but not sure of the rate of wear. A good friend of mine has a Pro-flite that has an alum. drum and uses chrome rings.However I decide to go I appreciate the responses. Thanks Joe

[Alan Roehrich]

Joe, if the drum is anodized or surface heat treated, honing it may go right through either treatment, leaving not only the ring wear surface soft, but also the bushing surface. It might eat itself and take out some other parts.

You'd be better off to see if you could get a sleeve made. Bore it to fit the sleeve then hone the ID as required. You might find a thick wall piece of thick wall stainless tubing with the ID being a few thousandths small, and then bore the drum for a to allow a 0.005" press fit. Drill the tube for the passages, cut it to length, press it in (I'd warm the drum up), then hone it to size.

[buzzinhalfdozen]

Thanks Alan, that plan has being been on my mind, having a hard time seeing how these scarf seals can actually seal well as they seem to have little to no tension to the drum bore. Joe

[buzzinhalfdozen]

Tom, very good point, I,ve considered the majority of wear would be caused by drum moving fore to aft.I,ve seen the metal seals eatin away to about half their thickness, but little to no wear to drum, more the seal wearing on the shaft. One more question....I've always heard that hard anodized parts are either Black or dark grey, this drum is Pewter in color. Joe

[Tom Goldman]

Anodizing can be done in any color ,including clear.
there are different processes that can enhance hardness,but bottom line is that it's still aluminum.
Alan's recomendation to install a thinwall sleeve is probably the best route....Ive done this to save a few PG drums over the years.
The reason the rings wear on the lands us usually due to the soft cast iron type ring ,and boosted line pressure.....Years ago when we were running a ClutchTurbo in a B/Altered we had to go to the teflon rings due to wear on the center support caused by the higher pressure we were running. ....Now ,years later ,I've been using nothing but the hard chromed rings in TH 400's ,and have not had a failure in years.
Every builder out there has their favorite combination. ...My preference ,especially on lower pressure S/SS type trans are the chrome rings. ...