Rear Brake drums

[elvimto]

Since I bought my Stag I have solved many problems with the aid of the good people on this Forum and others. I have had an issue with noise coming from the rear tyres and or wheels. Although I did not drive it much when I got it the car it had wire wheels and any of the noises were not noticable at the time. The original rear drums were at the max also the shoes linnings were cracked so I replaced the shoes and ran with the wire wheels for a bit. I have since changed the tyres and put on a set of recon alloys. I have no road noise from the tyres but I did get a drumming noise which could be the prop shaft out of balance or the rubber dampner going soft or some other component part creating it.
I did buy a set of rear drums along with some other rear end bits of Ebay, the drums were in good shape and one of the guys at work did a cut on them with a brake lathe,after fitting them I still had the a bit of a noise. I was going to cut them myself on a machine lathe with a four jaw chuck (that way you can zero the part in before cutting) but my workmate said he used to work in a tyre shop and it would be fine. Anyway after all this I fitted the newly machined drums did a bit of driving used the hand brake to seat the shoes etc and still had a tight spot on both drums when turning by hand. I just checked the fit on the drum to the rear axle where the register is and its a very tight fit 2.751 inch on the small bore on the drum and about 2.750 on the hub. I fitted one of the old hubs that came with the car which had been machined prior to me owning the car and had the same result. Given that all the other components are in good shape and I have no runout on the rear hub. This leaves me to believe that by machining the rear drums you can induce the noise that many people have reported. In essence the drum surface that contacts the shoe is tight on one side and has clearance on the other. I am going to buy a new set of rear drums and see what that does but I am just putting this out there to see if any body has had this problem. When I told my the guy who did the maching he did not believe me, i will follw up in due course.

cheers Stuart

[davidf]

When you say "no run-out on the rear hubs" - what are you measuring? I had a problem some years ago which I traced to the hub flange being distorted (possibly some PO attemt to strip the hub bearings?). I found this by fixing a dial gauge to the trailing arm, and running the tip on the outer edge of the flange face.

[elvimto]

I checked the face with a dial indicator and then also for end play in the bearings my note does go on a bit but if the people machining the drums do not get it right then you will have a problem.

cheers Stuart

[73stagman]

I removed all the paint from the centering hub before I chucked it in a three jaw. I then clocked the drum on the inner surface prior to machining and as it was less than .1mm (about 4thou?) total runout I figured it was pretty good. They weren't terribly worn though they just had some nasty rusty marks through standing still for so long.
We do have a very large lathe and i could have actually held the drums on the outer diameter! but was worried I might distort the drum like that so decided to chuck it up as described. There was no chattering at all and so the surface finish is fine. (photos on my "73 stag rebuild" posting)

[elvimto]

Don't think you will have any problems then, you live and learn.

cheers Stuart

[elvimto]

Just got my new brake drums so all brake parts are new drums, shoes, springs, brake cylinders etc. I put one side together and found the same result the drum gets tight after you start to nip it up. I can feel it just with the two countersunk screws that hold the drum inplace. All the settings are correct the self adjusters are correct but no matter what I try I still have a tight spot. Been at this for about four hours so its time to pack it in for the night. I get the same result no matter which drum I use. How much drag on the shoes should there be if any?
Of to sleep on it any suggestions most welcome.

cheers Stuart

[KOY 23]

Bent flange?

[elvimto]

Just rechecked them the flanges are good, muggy and hot here today that should make this job a bit more interesting.

cheers Stuart

[73stagman]

Have you run the car since fitting the shoes and drums? Maybe the whole shoe set up needs to centralize on the retaining springs and the wheel cylinders?

[elvimto]

Went back to work on the car started from scratch I found that the shoes had some high spots on them so in essence they were not round and in a central position. I used a course emery paper to remove the high spots and was able to fit the drums without them getting tight both sides good. I could hear the self adjusters working when the brakes were applied, test drove the car all seems fine. Some days are better than others. I still have a druming noise but I tend to believe that after eliminating all the other parts its now down to the prop shaft, still glad to have this bit done.

cheers Stuart

[StagnJag]

Have you checked/changed the quill shaft bearing? I had a drumming/vibration and eventually discovered that the cheap one I had put in had given up the ghost after only around 3000 miles!

Rgds

Dave

[Andrew S]

Dave's quite right, good point to check. These can go either because they are cheap versions out there or your front diff oil seal is leaking and it washes out the grease in the bearing. You should be able to feel up and down movement by hand but give it a good manhandle

[elvimto]

I went through the extension piece renforced it and used a SKF bearing car has less than 1000 on the current set up the diff I just swapped and I replaced the front seal I used a double lip seal made from viton so it should be good. I want to put a few miles on the car its fine if I keep it at about 55 which is not bad and I have a contact that has a prop shaft that I can have balanced eventually I should resolve this.

cheers Stuart