MM54

What are you guys who still have rear drums doing for the drums? I pulled mine tonight and they are worn past the specified max 201mm far enough I could see it with my ruler. I see rockauto lists "economy" centric ones and some out-of-stock-everywhere raybestos. Atkins has what I think are Mazda ones, but they're $60 a piece! Any suggestions? Get the cheap ones and hope to stumble across a GSL axle?

Ckforker

I'd try the cheap ones and you could even get them turned if they are slightly out of round for less. $60 a piece seems steep.

DivinDriver

iTrader: (15)

Considering the local Autozone is asking $103.99 each for Duralast 1980 drums... $60 doesn't sound too bad.

Qingdao

iTrader: (3)

Turn the drums before installing them. I have yet to see a true drum from the factory. Mostly because of how they are stored just stacked and jammed for years on end.

Banzai

iTrader: (13)

This is the 2nd thread I've saw in the past couple weeks asking about where / how to source drums. I wasn't aware that they are becoming hard to source. Maybe it's just harder to find them at the prices people are used to paying. I used to think that consumable parts like brake pads, drums, water pumps ect.. would be available forever. Now, I'm not so sure. At what point do critical things like housings dry up, which forces more and more vehicles off the road which in turn reduces the demand for the smaller consumable parts. At some point, will a lack of demand for the smaller items drive them to become scarce or unobtaium too?

KansasCityREPU

iTrader: (9)

I'm in the process of trying to buy drums for my 1979 and I can't find them in stock anywhere. Not RockAuto, Summit, Atkins. I did order from Summit but they are on back-order. The 1981-1985 won't fit the 1979/1980. Summit says they will ship from the manufacture on 3/19. We'll see.

t_g_farrell

iTrader: (1)

The centrics work fine. I have them on my SA now for a few years and didn't even get em turned. No pulsing or other symptoms of out of roundness.

MM54

I think the first gen is approaching the critical point where either the value of the cars will start going up and the aftermarket starts to pick up (it's pretty clear a lot of once-common parts are drying up) or they will become like so many other old, obscure cars which are very difficult to get most model-specific parts for, if possible at all for some. We're already seeing the latter with the lack of 12A parts available.

MM54

I received the cheap chinese Centric drums today - they look good. The box is marked 7/25/17 which I would have to assume means these are not old stock - the drums are fairly close in appearance to the factory ones but not exact. Definitely look like they should fit and work well - and being new production (not on a shelf for a decade+) I'm not too concerned about getting them turned unless I find later on they act out-of-round. Should get around to throwing a coat of paint on them and installing on the car later this weekend. Way better than the old drums, both of which show signs of having old shoes run down to the rivets (current shoes are at 50% I'd say) and one of which is grooved/lipped deep enough (at least .75mm) I had to back the adjuster way off just to pull the drum.

Ckforker

Keep us posted on how they work out. These are on my ever growing list of parts to purchase.

GSLSEforme

Chuck them on a lathe and see how much runout they have now,guaranteed they have runout-all new replacement rotors/drums do. From manufacturing to shipping/storing where they get banged around. Quality parts generally have less,cheaper have more.

As a professional technician,i always chuck a new rotor/drum on lathe to at least measure for runout and if needed remove what's necessary for 0 runout. Reason: time is money,nothing like roadtesting a brake job to find vibration/pulsation/shimmy present which means you get to do the job twice while being paid once to do it. My2c.

j9fd3s

iTrader: (3)

most brake rotors/drums (90%) come from one factory. they make the parts in different quality/spec levels, box it in your choice of box and slap your label on it.

MM54

Update:
I got the new drums, cleaned them up, put some paint on the outside (to prevent rust), and contemplated roundness. Since I don't have a lathe handy (and couldn't figure out a way to mount them backwards to the hub centered well enough to use a dial indicator to measure), I figured I'd just try them. Took the car out this past weekend (just around the block) for the first time on them, and oh yeah one's way out of round. After calling several places to find somewhere that will actually turn drums (the guy at Midas genuinely asked "What do you mean?") I had that done today for more than the cost of the drums! Will put them back on, and next time the weather clears up (and I get some other work on the car finished) I'll hopefully find them to be satisfactorily round.

MM54

WARNING

Chinese **** **** me again! Put the drums back on, they were clearly uneven turning by hand - only after the screws (or wheel) were in place. Messed with it for nearly two hours before figuring it out - they aren't out of round, THE FLANGE BORE IS TOO BIG - there is several thousanths of radial movement between the drum and the hub on both sides - the drums CANNOT locate on the hub so there is no way to have them work correctly!

t_g_farrell

iTrader: (1)

Did you use the 2 small screws to attach the drums to the wheel hubs? That should center em regardless of the center hub diameter. The when you put the wheels on they should hold it all in place once torqued.

MM54

Yes I used both screws - the holes in the drums for these screws are too big, thus sloppy, and allow the drum to move around even with both screws started. This is not the case with the OEM drums, which fit snug, if not tight, on the axle flange. Even the lug bolt holes do not line up with the hub quite right - the holes are bigger than OEM and for good reason, since I would not be able to put the bolts in otherwise!

I am going to grind the lip off the original very-worm drums and return them to service until further notice.

t_g_farrell

iTrader: (1)

Good to know, thanks for the heads up. Seems RA parts for cars are not the right sizes anymore or the quailty control is very bad. Somethings changed, and for the worse it seems.

MM54

As a conclusion on my part, here's the part and lot numbers from the box (they matched between the two) and the bore which is too large. I've boxed these up and am returning them under warranty for a refund; I'm still out the $60 (twice the cost of the drums) I spend having them turned, though. Some careful Dremel work and a cleanup by hand with 220 grit took the huge lip off the one original drum, so I've returned them to service. They're past the 201mm max diameter, but at least they work! I'll have to keep an eye out for a somewhat local GSL axle.

DivinDriver

iTrader: (15)

My experience with Rock Auto is that they will do their best to make things right... but it's hard for them to be responsible for mistakes by their suppliers until they know about them. It's not like they unbox and measure parts they sell.

Clearly this is a supplier problem. Hopefully, they will make it right, as we're running out of sources for these aging parts.

The BRAPmobile

Thanks for the update as I was just about to buy those same drums. I wonder if all of the aftermarket drums are like that?

tommyeflight89

iTrader: (4)

Not good about the drjms.

I have centric front rotors on my 1982 GS and have not had any issues. Centric must be hit or miss.

I need to source GSL rear rotors for a GSL rear end swap. The rotors locate to the axle the same way as the drums and also provide the hub cenrric engagement for the wheel.

Anyone have experience with rear GSL rotors that work fine or ones to stay away from? I was going to get centric...

j9fd3s

iTrader: (3)

Centric is just ordering from the same place everyone else is. in this case all they are doing is designing the artwork on the sticker, everything else is outsourced