Dolomitejohn Posted July 4, 2019 Report Share Posted July 4, 2019 Hi all. Just looking for some potential direction. My gt6 has some vibrations and noises from the rear. Vibration kick in at about 50 mph. I am sure there is a noisy wheelbearing also. I do know there is some slop on the uv joints. However there is a sharp knock noise that sounds like its from the rear left wing. With car stationary pressing up and down on the wing results in no noise. However if I push the rear left wing to the right it knocks once. Push again and nothing. Push the right hand wing to the left and I get the one knock from the left side. Totally repeatable. Any ideas before I get under the car? Cheers all. John Link to comment Share on other sites More sharing options...
Herald948 Posted July 5, 2019 Report Share Posted July 5, 2019 "Roto-flex" or "swing-axle / swing-spring" suspension? Link to comment Share on other sites More sharing options...
Dolomitejohn Posted July 5, 2019 Author Report Share Posted July 5, 2019 Non rotoflex. Very late car. Link to comment Share on other sites More sharing options...
Clive Posted July 5, 2019 Report Share Posted July 5, 2019 Vibration at 50 is classic prop in and/or balance. The knock.... I think you will have to concentrate on one thing at a time. Disconnect the lh shock at one end and see if it still knocks. Then spring eye. That enables you to feel the wheel bearing without it being under tension. Don't forget tie rods, I had one where a PO had helpfully used a 5/16 bolt (rather than 3/8) causing a knock when pulling away or braking. Easy fix that one... Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 5, 2019 Report Share Posted July 5, 2019 I echo Clives thoughts add in a bent drive shaft, easy to check jack up a little and watch the trunion stays undisturbed when you rotate the wheel , if the trunion gets moved /wobble the shaft has bent Pete Link to comment Share on other sites More sharing options...
Bob Horner Posted July 6, 2019 Report Share Posted July 6, 2019 Could be lots of things as stated but I had similar symptoms on a swing spring spitfire and turned out to be loose mountings on radius arm. A very simple fix! Bob Link to comment Share on other sites More sharing options...
Dolomitejohn Posted July 6, 2019 Author Report Share Posted July 6, 2019 My uv joints def have slack. I can see it. The clonk can physically be felt through the body work! If I hold my hand on the wheel arch at top centre. Could it be knackered chassis to body mount / bushes? John Link to comment Share on other sites More sharing options...
NonMember Posted July 6, 2019 Report Share Posted July 6, 2019 The half-shaft UJs MUST NOT HAVE ANY SLACK. You can get away with a little bit on the propshaft ones, but only a very little bit. Any play in the half-shaft UJs will cause bad handling, vibration, clonking, and fairly rapid terminal failure. Get them changed ASAP. Link to comment Share on other sites More sharing options...
Dolomitejohn Posted July 6, 2019 Author Report Share Posted July 6, 2019 Yes that's what I thought. I tightened the chassis to body bolt in the boot and masivly reduced the knock sound. So guess it needs new bushes all round. Hardly supprising I guess. Noticed today the shocks have girling on them. Must be old...... Got a list as long as the country of jobs to do.... Link to comment Share on other sites More sharing options...
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