I replaced my rear shocks today, no reason other than I'm doing all 4 corners at the moment and wanted a warmup easy job. While the back wheel was off I decided to check the condition of the drums/shoes. The drum/hub turns easily enough although there's a 'swish' suggesting it's not perfectly round inside - however I can't get the drum off. There was some kind of corrosion build up in the hub/drum/wheel area which even made removing the rear wheel harder than it should have been - I scraped away and wire burshed as much as I could but it looks like this stuff has fused the drum and hub together. Tried WD40 - nothing. Tried a rubber hammer - nothing. Tried a metal hammer - nothing.

Does anyone have any suggestions for dealing with this problem - is it common? Tempted to just take this issue to a garage. I saw another post about using some bolts where the wheel location studs fit but behind those it seems to be threaded too, I don't see how the bolt would do anything other than just make it even tighter?

Make sure the handbrake is backed off as far as it can go, you could even slacken the cable at the lever end if needs be. Then try to remove the drum by turning it and tapping it with a hammer as you do so. Don't use a rubber mallet as you need the shock effect to help dislodge it. You can also use a lever between the drum and backplate but go easy as you obviously don't want to cause damage. Work your way around opposite sides of the drum and inch by inch to ensure it pulls off as squarely as possible.

You can put bolts in two holes to force off the drum, note I destroyed the fitting kits in the process slackening off the hand brake won't help as the auto adjusters keep the shoes out it's was a pita

Yeah it's not the shoes binding stopping it thats for sure, I was turning the hub with a thumb and middle finger.at the non-swish point. The corrosion substance whatever it is, actually looked like someone had deliberately welded or sealed the drum to the hub, but it was just neatly shaped by the back of the alloy. I had to attack that stuff with a screwdriver before I could wire brush more off.


So the bolt method - what happens about the thread you can see on the hub behind the drum, does it just get destroyed or something? I've actually never seen anything like this and I grew up doing the drums on my Capri etc.

You remove the locating pins and use long bolts through they press against the shoes forcing the hub off a very crude way if the hubs been on forever as often they've not been off since manufacture I needed to remove mine due to the extreme rusting!

For the rare occasion that I have difficulty on a persistent hub, I use a hub puller, spreads the pulling power equally.

jimboy said:

For the rare occasion that I have difficulty on a persistent hub, I use a hub puller, spreads the pulling power equally.

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Can you imagine using one on my rusty hubs you could just pull bits off with your fingers, unless you pulled on the bolts inserted in the holes?

jimboy said:

For the rare occasion that I have difficulty on a persistent hub, I use a hub puller, spreads the pulling power equally.

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Not much use on a 500, since the hub fits closely into a recessed part of the backplate and there's nowhere to get a puller onto it.

Screwing greased bolts into the holes in the drums which the locating pins pass through is the way to do this. The bolts press against the solid metal of the hub flange and can exert a great deal of extraction force on the drum; just be careful to tighten them evenly. Once the drum begins to pull free, you can even spray some silicone lubricant onto the shoes, since you'll likely be scrapping both the shoes and the drums anyway.

Slackening the handbrake cables right off at the handbrake lever may or may not help; it depends on how much the adjusters have wound out and how lipped the drums are. However, slackening the cables is well worth doing, as it makes it much easier to get the shoe with the handbrake actuator off the cable once the drums are off.

On the last one I did, one shoe had seized against the backplate and the drums were too scabby to be worth trying to salvage, but the springs, wheel cylinders and self adjusters were all in perfect condition and could be reused. The drums came off easily using extractor bolts. They were the original rears on a 9yr old UK car with about 90k on the clock.

Gotcha, never worked on the 500, those hubs did look very scabby indeed.

jimboy said:

Gotcha, never worked on the 500, those hubs did look very scabby indeed.

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They're just unpainted cast iron, so corrode quickly in the UK climate unless treated. Best to give them a coat of paint when new, but who wants to have to do that on a brand new car?

jrkitching said:

They're just unpainted cast iron, so corrode quickly in the UK climate unless treated. Best to give them a coat of paint when new, but who wants to have to do that on a brand new car?

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Certainly not having a go at the chap, but I'd have changed the hubs long before they became that bad, you should be giving the likes of brakes the once over from time to time, a brand new car you say...

jimboy said:

a brand new car you say...

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That one wasn't, but I remember taking the drums off my own 3 day old 500 to paint them. Not what you'd expect to be doing to a new car.

jimboy said:

Certainly not having a go at the chap, but I'd have changed the hubs long before they became that bad, you should be giving the likes of brakes the once over from time to time, a brand new car you say...

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We bought the car a six years old and that's how they looked!
And this was the rusted through leaking shock absorber also now replaced .

John202020 said:

We bought the car a six years old and that's how they looked!
And this was the rusted through leaking shock absorber also now replaced .

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Aye!! that did not look good, keep up the good work though. It's such a pity that right across the Fiat range needs constant looking after some what more than it really should. Hey ho it is what it is..

jrkitching said:

Screwing greased bolts into the holes in the drums which the locating pins pass through is the way to do this. The bolts press against the solid metal of the hub flange and can exert a great deal of extraction force on the drum

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Here's the problem - if I remove the locating pins there's a thread in the drum, but behind that is a thread in the hub. How can it ever put pressure on the drum to free from the hub if the bolt is going straight through them both?

Funny thing is the drums barely look corroded at all, there's only one outer edge with the paint flaking. The corrosion is some kind of white crumbly stuff where the metal surfaces touched - in fact you cant even see that a gap exists between drum and hub, it makes them look like a single piece of metal. Some kind of chemical reaction between the metal types I guess.

If you don't really need them off leave them though it will male it harder later.
The bolts press against the shoes if in the right place as it's these that's the issue, pushing the hub off away from the shoes.
Got alloys? The white is corrosion between steel and aluminium there are those that say don't put anything on the surface but I've painted mine without issue, the hubs

system11 said:

Here's the problem - if I remove the locating pins there's a thread in the drum, but behind that is a thread in the hub. How can it ever put pressure on the drum to free from the hub if the bolt is going straight through them both?

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The threaded holes have different diameters.

The bolts used for extraction are larger and won't pass through into the thread in the hub; they'll put pressure on a part of the hub that's outside of the thread for the locator pins.

John202020 said:

The bolts press against the shoes if in the right place as it's these that's the issue, pushing the hub off away from the shoes.

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No, they don't press on the shoes; they press on the hub flange.

They're used to extract the drums, not the hub; the whole point of using them is to leave the hub in place.

Correctly sized extractor bolts won't pass into or through the hub.

Removing the hub is a different proposition, but you'd only need to do this to replace a wheel bearing; the hub stays in place if just replacing the shoes and drums.

jrkitching said:

No, they don't press on the shoes; they press on the hub flange.

They're used to extract the drums, not the hub; the whole point of using them is to leave the hub in place.

Correctly sized extractor bolts won't pass into or through the hub.

Removing the hub is a different proposition, but you'd only need to do this to replace a wheel bearing; the hub stays in place if just replacing the shoes and drums.

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I will have to look I'd swear you can poke a screwdriver right through the hole once the stud is removed
And yes I've confused hub and drum terms

John202020 said:

I will have to look I'd swear you can poke a screwdriver right through the hole once the stud is removed

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You can - the threaded holes for the locating pins go all the way through the hub flange. But the tapped holes through the flange are of a smaller diameter than the tapped holes in the drum, and so the larger bolts used for extracting the drums are stopped by the flange when you screw them in. The wheel locating pins, being a smaller diameter, are a clearance fit through the tapped holes in the drums.

Quite a clever design really. I've seen plenty of other marques with holes in the drums that are tapped for extractor bolts, but this is the first time I've seen the use of the same holes for wheel locating pins.

I've heard it said that not all aftermarket drums have threaded locator pin holes, so something to check when buying drums (unless you're prepared to go to the trouble of running a tap through the holes before you first fit them).

Without the threaded locator pin holes, these drums would indeed be a pig to remove, since there's no easy way to get a hub puller onto them.

A thin film of a suitable anti seize compound on the hub flange also makes removal much easier (unless the inside of the drums are badly lipped), but this isn't used when fitting the drums in the factory, so by the time most folks first remove the drums, they're well corroded onto the hub flange.