Amazon: Seized brake drum

[Alex122]

Hi guys. Today I tried removing one of the rear brake drums on my 1964 121 but even though I was using the correct drum removal tool it simply refused to budge. Unfortunately in my failed attempt it looks like I've mushroomed the end of the axle half shaft so that the large castellated nut won't now go back on. I now can't safely drive my car and it's my daily!! I have a few questions, firstly is mushrooming of the end of the half shaft a known problem? Secondly I assume the easiest solution would be to replace the axle shaft, but as my 121 is an early 1964 version, are the axle shafts the same as on later Amazons? I suspect my rear drums have never been removed as it is a low mileage 2 owner car and have now totally seized themselves on? I may have to destroy the drum to get it off. If so, are the rear drums from later Amazons the same, as I'm sure there aren't so many parts out there for early Amazons? I'd be very grateful for any advice tips as I'm 20 years old and this is my first classic.

[123GT-AMAZON]

Originally Posted by Alex122

Hi guys. Today I tried removing one of the rear brake drums on my 1964 121 but even though I was using the correct drum removal tool it simply refused to budge. Unfortunately in my failed attempt it looks like I've mushroomed the end of the axle half shaft so that the large castellated nut won't now go back on. I now can't safely drive my car and it's my daily!! I have a few questions, firstly is mushrooming of the end of the half shaft a known problem? Secondly I assume the easiest solution would be to replace the axle shaft, but as my 121 is an early 1964 version, are the axle shafts the same as on later Amazons? I suspect my rear drums have never been removed as it is a low mileage 2 owner car and have now totally seized themselves on? I may have to destroy the drum to get it off. If so, are the rear drums from later Amazons the same, as I'm sure there aren't so many parts out there for early Amazons? I'd be very grateful for any advice tips as I'm 20 years old and this is my first classic.

X

Hi ya

Phone Brian at amazionia he's got the bits your after there a complete rear axle I think if u need it he's in the driver or linked on my website on Volvo parts secondhand

Www.phenix-classic-restorations.co.uk

Good luck kind regards
Robert.w

[volvonic272]

Simon,
Have you got any further on?
Are all four plugs firing, does the rotor arm turn when the engine is turning over?
When you set the ignition timing is number one cylinder at the top of its stroke.
Feel the valve rockers for number one cylinder through the oil filler cap hole there should be some play/ loose.
As Rons says is the coil working ok?
Is the petrol getting from the pump to the float chambers.
Has the fuel pipe collapsed internally.
Is it the correct dizzy cap, swop it with the one you took off.
All stabs in the dark mate, I'm afraid.

Dave

[Ron Kwas]

Alex;

Even if you used an approved puller, if you did not put the nut back on to reinforce the Axle end, you did not use the correct and approved procedure, and that resulted in damage. Drums do not seize onto Axles, but are stretched onto the tapered shaft by way of the huge force multiplier of the tapered joint and nut, requiring super high force to remove, and this force must be applied only correctly! (Too Late!)

At this point, I recommend filing damaged threads of axle (with a triangular file...yes it's a B***h, but you brought it on yourself!) until nut can be replaced, then use approved puller again with the approved techniques and procedures to remove Drum.

I request you take pictures of damaged axle which we can help you decide if it needs replacement, and which I can add to the following article: http://sw-em.com/Brake_Drum_Notes.htm

Good Hunting!

[Volvorama]

As I recall all 120 drums are the same although late B20 cars have a hole for brake adjustment they can be retrofitted. There are some earlier cars with different half-shafts that have finer threads on the end and do not have the same splines.
I have removed severely seized drums using the real Volvo special tool 9991791 which has a rotating bearing surface that reduces damage to the shaft end. The ultimate trick was to do up the puller to a fearsome torque (we used a long/3' snapon breaker bar) and then leave it with a butane torch playing on the hub part of the brake drum. We retired to a safe distance and after about 10 minutes there was an enormous bang and drum+puller were deposited about 5' away from the car - undamaged!
The late, great 940Turbo also had a device to attach to the drum to stop it rotating by bracing it against the floor or chassis.

[classicswede]

Clearly that method has worked for you but it is not the right way to do it. Tightening the crap out of the puller usually ends in stripped threads.
The best way is to tighten it reasonably tight with a good ratchet or short bar. The hit the end with a big hammer to shock the drum off.

[nozamaman]

One thing to check are the brake shoes adjusted tight, many years ago I worked on a friends amazon could not get tne drums off with the approved puller the reason was the drums had deep wear groves in which the shoes sat restricting the drum coming off. Once the adjusters slacked right off the drums came off after a lot of sweat. They were replaced with unworn drums.

[Ron Kwas]

Comments to posters:

Cl_Sw; "...not the right way to do it. Tightening the crap out of the puller usually ends in stripped threads." I fail to see what's wrong with Volvorama's technique...the only specific thing he did wrong is not replace the Nut, such that there was a risk of compressing the Axleshaft-end and doing damage, and that when the stretched-on joint finally released, it allowed the Drum to unnecessarily shoot across the work area...but before impact force can have any affect, the Puller must be tightened to fully take up all slack, plus make huge steady pulling force, so of course one has to tighten "the crap out of the puller", otherwise impact would simply taken up tightening the puller more...and what threads are you talking about stripping? ...those on the Axle?...I fail to see how those could be stripped since there is ZERO force on nut and them... or those on the puller (if so, it's an inadequate tool!). Compression of axle threads occurs as a result of not reinforcing the shaftend with Nut, but that is a different issue.

The bearing Volvorama speaks of SVO9991791 having is an interface between the rotating Puller shaft and non-rotating Axle...that bearing prevents damage to the shaft-end surface, but it still must transfer the astronomical compression forces...I simply apply a slight film of graphite grease between the two surfaces with the same protective result! What is crucially important is to reinforce the Axleshaft-end with the nut to prevent mushrooming the threaded end (additionally weakened by the cotter-pin holes).

noz...; I think you are combining two different aspects of removing the Drum...breaking the initial stretched connection to tapered Axleshaft (and this requires the irresistible pulling force applied by the Puller, and sometimes more, in the form of impact and thermal...), then actually removing the Drum and its Wear Lip past the Brakeshoes, which backing off the Adjuster will help with, if the Wear-Lip is excessive.

...but that is the easy part...if Adjustor is free to move (often they are galvanically frozen...different issue again!), the puller can easily be used to apply its irresistible force to pull the Drum with its Wear Lip past the Shoes. I do recommend grinding away the Wear Lip while Drum is removed, to prevent difficulties at future removals...but it is important to note that backing off the Adjuster will not help breaking the initial stretched connection, which is strictly between Drumhub and tapered Axleshaft!

Cheers

[grahamwatson]

Ron and I (and others) had quite a long discussion about seized hubs on a thread about a year ago. I had (and still have) a seized hub on my 122S. I needed to get the drum off to replace a handbrake cable. Eventually I worked out that I could replace the cable without removing the drum. That got me through the MoT but there will come a day when the drum has to come off.

I was using a proper puller and using the approved method, including leaving the hub nut on the shaft to avoid mushrooming. That would also have avoided collateral damage from a flying drum but I never got that far, despite copious amounts of heat and considerable impact violence. A major problem is that you cannot get heat directly to the seized area because it is inside the drum.

Ron's final suggestion was to set the drum in a liquid nitrogen bath before applying the heat, to maximise the temperature differentials. I haven't tried that but I expect that when the time comes, I will have to cut the drum off. I have decided that if it comes to that, damage will be minimised by cutting through the face of the drum so as to remove the drum circumference. That will allow access to remove the shoes so that heat can be applied directly to the shaft of the drum. If the wheel studs have been left on the drum, the puller can still be used and, if successful, will mean that only the drum has to be replaced. Any other angle of attack with the grinder is sure to cause damage to other parts.

Although I have been living with the seized drum it has never been far from my thoughts. Just yesterday I bought a can of penetrating oil with "added graphite" which I had never seen before but which brought to mind Ron's graphite crusade!

[old fart]

I've recently removed the drums from my estate project, doing everything as described by Ron, tightening the puller up with a 4 ft scaffolding pole and giving it several thumps with a sledge hammer. Neither came off at the time, so I left them under tension and gave them a thump and a tweek with the scaffold pole every time I went into the garage. The first one took 2 weeks to come off and the other one 4 days. Good luck.