Rear wheel clunking when braking hard

[JavaG66]

I need help diagnosing a noise. When I brake hard, I hear a clunk, clunk, clunk coming from the right rear wheel. Moderate braking is quiet. Braking action seems to be good. I rebuilt the brakes to include rear drums, shoes, springs, wheel cylinders, axle seals, and parking brake cables. The brakes have been adjusted so that neither shoe drags, but one notch further on the adjuster wheel will produce rubbing for about 30 degrees of rotation. What ya think could be wrong? Thanks!

[exprof]

Take a look at the shocks and shock mounts. Also, make sure that the other suspension components are tight. It also wouldn't hurt to take a look at your CV joints.

Hope this helps...

[fatalifeaten]

Have you had the drums turned? Sounds like they could possibly be out of round.

[JavaG66]

CV Joints: don't have any of those.
Rubber: Shocks are solid and the big bullet tip for big bumps is intact. There is probably other rubber somewhere but I couldn't see it.
The brake drums are new, so I assumed that they would arrive round and true. Bad assumption?

[volksbugusa]

javag66
did you do any bearing work? did you remove the bearings or re pack the bearings?scraping noisescan be top to bottom movement on the bearings on the shoes,Some times when you install new drums and they are not GERMAN they will klunk on the rear plates.how many miles did you but on the new stuff..the only reason why i am asking is you will be able to see where things are rubbing due to new wear marks or scrapes..
also learn how to use a dial indicator...if you need more help then email me at

mdazzo@optonline.net

and i will email you my phone number to talk..
volksbugusa

[JavaG66]

Hi Volksbugusa,
We might be getting somewhere here; you have offered several items to evaluate.
Bearings: I did not replace them based on guidance from Muir, but I can't conclusively rule out bad bearings. The car has 106k miles. I did inject some grease in them with a needle tip.
Drums: they have about 500 miles on them. I am a bit reluctant to pull them back off because of the axle nut chore but will if you think that is the best place to diagnose. They are not German ; I got them from BFY Obsolete Parts and they only listed "new". They might be Brazilian.
Do I need to invest in a dial indicator set? And if I put up with this awhile, what kind of consequences am I looking at, safety wise?

Thanks for your willingness to help offline, I may eventually take you up on the offer. In the meantime, others may be interested in how this plays out.

Hal

[volksbugusa]

Hal:
Yes I would pull off the drums..you really have no choice.It is not wise to force new grease into any bearing without first cleaning the bearing thruout.Different types of grease mixed together cause more harm then good.The dial indicator will help in letting you know if things are turning out of round...cheap investment ...and a great tool..again pull off the drums....look for NEW WEAR STOPS... also look on the edge of the drum and the back plate for new wear spots.. really check things out...send me many pics to
mdazzo@optonline.net

volksbugusa
matt

[JavaG66]

Let's put this on hold a couple of days. I'll pull the drum off the first of the week and inspect it and the backing plate for wear patterns. And give me a day or so to run down a dial indicator and base; it generally doesn't take much persuasion to get me to buy a new tool!

[JavaG66]

A couple of weeks has turned into a couple of months! Thanks to all of you that helped with suggestions. Turning the drum cured the problem. I would not have thought a new drum would have needed it, but obviously I was wrong!

Regards,
Hal