The Popping sound

[moosetestbestanden]

When do you get this "pop"? What does it sound like exactly?

As I release the clutch and start moving the car, and occasionally when changing gears. I can accelerate sometimes w/out any problems and sometimes not.

The sound is basically identical (from my broke, bogus car, college day experience) to the sound of a driveshaft U-joint about to blow. A 'pop' or 'clunk' iow.

I checked the drivesha..., er, prop shaft (English English, old boy) when I had the car up in the air last weekend and it seems ok, no slop or free play was evident. Ditto the halfshafts, unfortunately. At this point I'm basing my rather thin diagnosis on both the nature of the sound and where it seems to be coming from. It could be coming from the rear end or (less likely) the clutch. Ugh.

I demonstrated and discussed it w/ Will. He said that he had experienced a failure of a halfshaft and told me the untoward motion was not radial slop (in the direction of rotation iow) but rather 'vertical' (or back and forth along the halfshaft's axial centerline). He mentioned that there were some halfshaft problems w/ CC at some point in time. I haven't as of yet contacted CC regarding the matter. I'd like some second opinions before getting in touch w/ them, and so going up to the track to meet w/ many other owners seems like a good idea. Once underway at a(ny) constant speed there does not seem to be any ill effects such as vibration or anything of that nature.

Besides, I've got an AAA card!

[magnusfeuer]

Hmm.

It can be that something in your suspension is loose, and that it settles in two different positions as you accelerate and brake.

Try to rock the car back and forth with the handbrake engaged and see if you can reproduce the sound. If you hear suspicious sounds (apart from your own grunting, from which your neighbors surely will deduce that you are having sex with your car), get under the car and try to find loose parts in the suspension by pulling and pushing them.

Especially the A frame/De Dion tube mating is known for developing some play every now and then.

If you bring the car to Willow Springs, we can all rip it to pieces while arguing about what is wrong. Wouldn't that be great?

/Magnus F.

[moosetestbestanden]

I examined just about everything when it was up in the air, to no obvious effect - obviously. I'm lifting it again tonight to go through the possibility you suggest and also to look and see if the brake caliper(s) may be loose, as suggested by Will.

If you bring the car to Willow Springs, we can all rip it to pieces while arguing about what is wrong. Wouldn't that be great?

Sure. As long as I can drive the track while you all wrench!

[Elv15]

clunk

What maguns said is true, check all of the suspension bolts. Check the engine/tranny mounting bolts. Check the diff mounting bolts (this is a frequent cause of such knocks). Check the large nut's on the axles (one was loose on my car and caused a similar noise). I also had the front A-arm camber lock nuts loosen.

Cheers,

Tom

[slomove]

I had clunk noise for a while until I noticed that I almost had lost the lower right front suspension ball joint. So, better check your nuts :mrgreen:

Gert