TheSamba.com :: View topic

Wed Mar 28, 2007 1:24 pm

Hi all,

Edit: I should have said, it's a 1973 GT Beetle!

I'm trying to figure out the source of a rattle on bumps and would like to draw on your collective wisdom! It sounds like it's somewhere under the rear parcel tray.

How hard should the transmission mounts be? My rear ones seem to have a little bit of 'squish' to them, for want of a better word, but I've never felt a new one to know the difference!

How does one test the front transmission mount? Is a worn front mount the kind of thing 'you'd know about' when driving? There's no trouble shifting and no drama when pulling away hard from a stop (apart from a slight smell of rubber :wink: !).

Interestingly (to me anyway!) the rattle only seems to be there when I'm on my own. This makes me wonder if it could be worn Z-bar bushings, as I read somewhere that the factory Z-bar only comes into effect when there's a bit of a load on the suspension - is this the case? If so, could an extra person or two constitute enough of a load to activate the bar and hide the rattle?

Finally, the rattle is worse in the morning - bizarre or what?!

Thanks very much!

Michael

PS: I replaced the shift rod bushing last weekend - easily the most worthwhile couple of hours I ever spent working on a car :D !

Wed Mar 28, 2007 1:29 pm

If there isn't any discernable movement in your shifter when you accelerate, chances are the tranny mounts are doing their job.

Look at your shocks and z-bar.

-jeffrey

Wed Mar 28, 2007 1:32 pm

Check body mount. Rubber bushings should be between body and mount. Bolts should be tight. The rubber bushings have a way of deteriorating, and can cause a nasty rattle.

Pic for reference is early body on late pan, but you get the idea.

Wed Mar 28, 2007 1:58 pm

Thanks guys, I'll check those out.

Michael

Thu Mar 29, 2007 2:44 am

Could also be the shocks (happened to me), you can remove them and go for a drive to see if the rattle is still there.

Thu Mar 29, 2007 5:31 am

Uncle Bob has found it for you, I bet. Check those mounts.

Fri Apr 20, 2007 11:30 am

Hi all,

I finally got round to checking everything out!

The shocks were pretty wallowy during the bounce-test (plus it was a little unsteady on bumps on the motorway - 70mph - last week), so I replaced them with a pair of KYB GR2's - what a difference, it feels like a car again! Having seen the state of the old ones when I removed them, it's a wonder they did anything at all! Body mounts were fine, Z-bar looked fine and I was ready to live with the noise.

Rebuilt the brakes this afternoon and, lo and behold, whilst adjusting the driver's side, noticed that the bottom Z-bar bushing (on the hole on the trailing arm) was worn out over a distance of about 10mm. I gave it a manly wiggle and I reckon that's my rattle solved! It would also explain the intermittent nature of the noise, as it only knocks when it hits that bit of the bushing. So, gotta get the bushing then hopefully I can look forward to rattle-free bumps!

Thanks for all your advice and pointers, they were greatly appreciated!

Michael

PS: I bought a Torquemeister to deal with a massively over-torqued axle nut, as my four-foot cheater pipe was bending the wrench before moving the nut! The Torquemeister didn't seem at all fazed by it, just got on with undoing it - those things are absolutely worth their weight in gold, every home should have one!