Click-Click From Right Rear Wheelend

[Chris Bunker]

Hello all-
A bit frustrated here, I just got my car (78 SC) back on the road after redoing the spring plate bushings and an alignment, and I now have a strange clicking coming from the right rear corner.

The sound is a click-click (in quick cadence) that occurs once per wheel revolution, in forward and reverse. I jacked up the rear end and spun the wheels by hand and there was no clicking. I ran my hand all around the inside of the wheel to see if anything was rubbing on the caliper or something, nothing. I push and pulled on the wheel to check the bearings and there is no perceptable play. Once it was down I thought to check the axle shaft. I was not able to feel any freeplay (torsionally or along the centerline) in the axleshafts.
I drove it up and down the street afterward, and the noise was still there.

The only thing I can think of: when I changed out the spring plate bushings, I did not remove/unbolt the axleshafts from the stub axle. Could I have unduly stressed the CVs by not doing so?

I did not notice the noise when driving to the shop that did the alignment, nor on the drive home. Someone pointed it out to me in the parking lot of the video store after a 40 mile trip on the highway. Of course, now I can't help but notice it.

Puzzled in MI,
Chris

[Allan Broadribb]

Sounds like the CV joint to me.

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Allan Broadribb
'70-911E, 2.2l with Webers
http://www.cheaterswayside.com/uploads/Mvc-002s355.jpg

[MBradbury]

Hi Chris,

This is the most amazing coincidence. I spent the whole winter rebuilding the chassis, including new spring plate bushes etc. I lowered the height to 24.5 rear and 25 front and then drove it down to a Porsche specialist for a 4 wheel alignment. The car felt pretty good on the 15 mile drive to the garage. The garage phoned me up to tell me the work was complete and did I know my RHS CV was clicking. I said I didn't, but that because it was the only part I hadn't replaced in the rebuild I would do it myself. Well, when I collected the car and drove it home, sure as eggs there was a load clicking on moderately hard right turns. I thought like you that the CV may have ben stressed when I ran the engine for short periods with the suspension disconnected. Well, to cut a long story short I replaced the CVs and the clicking is still there. I am racking my brains too what is the cause. It almost sounds like something loose underneath. The other coincidence is we are both from Michigan. Spooky! Where did you take yours for the alignment?

If you have solved the problem, please post the solution.

Regards
'83 SC Coupe
Michigan

[Chris Bunker]

My car clicked in a straight line, not necessarily only in a turn. It has a strange cadence, a real quick "click-click" then nothing until it comes around again. I did a Drivers Ed with it yesterday at Waterford Hills and it didn't seem to worsen any. I don't know, I need to do some other things like look over the brakes and adjust the front bearings, so when I have it up I'll go over it real well and see if I can pinpoint it. The other strange thing was that it went away when it was off the ground.

Did you do a whole new/rebuilt axle assy, or just what you thought was the offending CV?

I live in Ypsilanti, so I took it over to Eurotech in Ann Arbor, they are actually only about 4 miles from my house. The place comes highly recommended by some people I've talked with in my region (Rally Sport). Where are you located?

Chris Bunker
78 SC

[MBradbury]

Hi Chris,

Thanks for the reply. It doesn't seem like we have the same problem after all.

To answer your question, I replaced both halfshafts with rebuilt ones. The old ones weren't too bad when I took them apart, with only minor pitting on one of the four CVs. I have new bearings on the rear as well as bushings on the sway bar and spring plates. There's a lot of new piping also to accommodate new SSI Heat Exchangers. One thought I have is that even though the ride height is nearly equal fender to fender, there may be difference between the spring plate inclinations. This is undesirable at best, plus I'm running out of theories. So I may reset the height again this time paying more attention to equalizing the spring plate angles.

I live in Troy on the other side of Detroit to yourself. I used Fred Lavery in Birmingham to do the alignment work. I was ready to take it back but I don't think it was anything they did, plus I'm determined to reason out the problem myself. If I solve it I will post the answer.

Mark Bradbury
'98 SC Coupe
Michigan

[Bob W.]

A stone stuck in the tread of the tire will click on the road as you drive. Sometimes it can be loud.
Bob W.

[Bob W.]

A stone stuck in the tread of the tire will click on the road as you drive. Sometimes it can be loud.
Bob W.

[Early_S_Man]

The emergency brake cable can cause a 'cricket-like' chirp or click-click once per wheel rotation ... if it is not perfectly aligned and clamped in place. This can happen when rotors are turned and replaced, if you adjust or clean & replace things in that deep, dark recess that the e-brake shoes and mechanism live!

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Warren Hall
1973 911S Targa

[Chris Bunker]

The first thing I checked when the guy in the parking lot said I had a ticking coming the rear of the car was the tires, I have pretty sticky rubber and I had just driven over a section of parking lot where they had torn up the pavement. No such luck though.
I must say Warren, your suggestion sounds to be the closest to what I am experiencing. I will have to take a much closer look. What part of the parking brake cable makes contact? Do I need to pull the rotor to check it out? Thanks for the help.

Chris B
78 SC

[Chris Bunker]

Well its been awhile since my problem first started, and I've done a lot since then, but it still has not gone away.

I pulled the axles and pulled apart the CV joints. They looked really bad, and I thought for sure that was the problem. I bought new joints, loaded them up with Swepco 101 and put the axles back in place.

I also decided to rebuild the brakes since the pistons looked quite bad and the dustboots were all burned off. I bought new SS pistons from Stoddards, blasted and powdercoated the calipers and installed Pagid oranges. I guess the main point of this section is to explain that I had the rear rotors off and I cleaned up and greased the parking brakes, as well as adjusting the cables. Nothing appeared to be amiss during disassembly.

I thought for sure I was going to have this *&%#@ licked, but sure enough, I got my car back on the road yesterday and the damn thing STILL makes the clicking noise!!!!

The only thing I haven't touched back there is the stub axle bearings, but it just doesn't sound like the rumbling that bearings make when they go bad, not that I've ever heard bad bearings in the rear of a 911 before though. Besides, they is no real play at the rear wheel to suggest it was a bearing.

I am at a loss for what to try next. Warren, any chance you could elaborate a bit on your park brake cable suggestion???

[MBradbury]

Chris,

Hi, just so you don't feel lonely, I haven't solved my clicking problem either. It dosen't sound like we have the same problem, but I am monitoring the thread for ideas.

I thought I would let you know all the parts you have mentioned I swapped-out during my winter chassis overhaul. The only part I didn't do myself were the bearings. I left that job to a Porsche gararge because of the special tool requirements. Although, after receiving the bill I could have probably bought the tools, and I wouldn't have this nagging feeling they could be the problem. The likelyhood is small though. My attention has moved to the engine mounts. The theory is they're tired out and the RHS transmission mount cup washer is banging against the cross member on cornering.

Best of luck and keep the thread going.

Regards
Mark '83 911 SC Coupe

[Early_S_Man]

Chris,

Once, after I had taken the rear rotors off during a caliper rebuild, and removed, disassembled and cleaned all of the rust from everything in the parking brake assembly ... put everything back together with fresh paint and anti-sieze conpound where things rub ... readjusted the parking brakes to perfection, and everything worked fine. Except ... that there was a click or cricket-chirp-like noise, once per wheel revolution, noticable from the very start of the test drive, backing out the driveway!

The noise hadn't been there before the brake work, and the CV-joints had been repacked and operating perfectly for three months, so it had to be something do do with the rear rotors and the brake work. It didn't take long with the tail up on jack stands to locate the problem as inside the left rear rotor, so, as much as I hated to break the hydraulic circuit again, with it full of freshly-bled DOT 5 Autodyne silicone brake fluid (Lyn St. James' company, a regular Autoweek advertiser in the '80s) ... I pulled that caliper off and proceeded to take the rotor off and have a look. The spring around the E-brake cable was bowed-out slightly too much because it was off-center and not seated correctly against the backing plate! It had been rubbing on a 'high-spot' on the backside of the hub, once per revolution. Less than two-minutes to fix the problem, and another half-hour to put things back together and re-bleed the rear brake circuit, and the click/chirp was GONE!

So, the moral of the story is ... rotate the hub/rotor assembly and listen for anything rubbing or hitting inside BEFORE YOU DO THE CALIPERS ... if you have had the E-brake assembly apart!!!

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Warren Hall
1973 911S Targa