hypoid53 Posted October 15, 2014 Share Posted October 15, 2014 I am experiencing a bit of a problem with rotoflex GT6 rear shocks.The top mounts are on shock extensions off the chassis but a banging noise is still experienced from the LH rear. The photos clearly show a difference in the compression of the shocks when stationary. Look at the position of the blue sleeve relative to the GAZ logo.The car drives well; has been laser tracked on all 4 wheels and sits perfectly on a new Canley spring. The new GAZ shocks are the correct length ones for the top mount modification from the TSSC. To lessen the banging they are currently on setting 9 out of 12 which is a bit hard! Top mount measurements to the ground are identical. Any ideas what could be causing this? Quote Link to comment Share on other sites More sharing options...
John Bonnett Posted October 15, 2014 Share Posted October 15, 2014 hypoid53 wrote:I am experiencing a bit of a problem with rotoflex GT6 rear shocks.The top mounts are on shock extensions off the chassis but a banging noise is still experienced from the LH rear. The photos clearly show a difference in the compression of the shocks when stationary. Look at the position of the blue sleeve relative to the GAZ logo.The car drives well; has been laser tracked on all 4 wheels and sits perfectly on a new Canley spring. The new GAZ shocks are the correct length ones for the top mount modification from the TSSC. To lessen the banging they are currently on setting 9 out of 12 which is a bit hard! Top mount measurements to the ground are identical. Any ideas what could be causing this?Funny thing, before I put the body on mine when I bounced up and down on the chassis there was a banging from the nearside. I didn't spend much time trying to track it down but it wasn't obvious where it was coming from. Not much help I'm afraid but I will be interested to read any replies. Quote Link to comment Share on other sites More sharing options...
Phwoar Posted October 15, 2014 Share Posted October 15, 2014 Shouldn't make any difference but have you swapped the shockers over to see if it does?If the ride height is the same on both sides and the shocks are identical then the asymmetry must be caused by different mounting points, or methods, L to R. Quote Link to comment Share on other sites More sharing options...
Slimboyfat Posted October 15, 2014 Share Posted October 15, 2014 How much fuel did you have in the tank when you took those pictures? Quote Link to comment Share on other sites More sharing options...
Richard B Posted October 15, 2014 Share Posted October 15, 2014 Sure it's not the spring rather than the dampers? Quote Link to comment Share on other sites More sharing options...
JensH Posted October 15, 2014 Share Posted October 15, 2014 Bent vertical link? Quote Link to comment Share on other sites More sharing options...
hypoid53 Posted October 15, 2014 Author Share Posted October 15, 2014 Slimboyfat wrote:How much fuel did you have in the tank when you took those pictures?Slightly more than 3/4 of a tankQuote:Sure it's not the spring rather than the dampers?No, but it is a new Canley spring and the car 'sits' right. The banging was present with the previous OE spring as well.Quote:Bent vertical link?Cannot be ruled out, but unlikely. It was checked before fitting against the WM specs and was a mirror of the RH side. Tracking is spot on. Quote Link to comment Share on other sites More sharing options...
daedalusminos Posted October 15, 2014 Share Posted October 15, 2014 What's the difference side to side from shock absorber stud-stud? Quote Link to comment Share on other sites More sharing options...
Slimboyfat Posted October 15, 2014 Share Posted October 15, 2014 hypoid53 wrote:Slightly more than 3/4 of a tank.About 25 kilos then. That would explain the left to right difference on a GT6 (GT6 has petrol tank way over on the left hand side of the car).On the US GT6 Triumph fitted a spring spacer on the left hand front coil spring to compensate for petrol tank, and driver (sits on the left!).I say its the shock knocking due to having insufficient range of movement which is common on this conversion. Quote Link to comment Share on other sites More sharing options...
hypoid53 Posted October 15, 2014 Author Share Posted October 15, 2014 Quote:I say its the shock knocking due to having insufficient range of movement which is common on this conversion.I tend to agree but what can be done about it. These are GAZ shocks. The same problem arose on Konis fitted previously.Can the manufacturer alter the specification to correct this problem? Quote Link to comment Share on other sites More sharing options...
GT6 M Posted October 15, 2014 Share Posted October 15, 2014 3 things come to mind1, the shockers are the wrong type, , IE original roto shockers2, the actuall shocker has a fault, I have a pair, and the car developed a nok frae,t passenger side.was found to be shocker its self, banging frae inside its self.3, ye say, ......To lessen the banging they are currently on setting 9 out of 12 which is a bit hard! there is a condition called shocker pull doon, ie, the shockers settings for fliud flow, are strang,r than the springs deflection rate, so as yer going along, the car slowly gets lower and lower, till it bottoms oot.thats why springs need to be matched to dampertry it on other side, see if it still noks,if it noks on other side, then its shocker.still sitting low on one side at rest, then maybe front springs are weak, set wrong,or chassis twist,or maybe even the VL threads are coming oot the trunnion, lowering that side onlytry and show a pic of underneath cr showing full length of car, so can see if car is actually sitting flatif left front is doon, then right rear will be up, and vice veraedit, is the car got a lowering block in it ,!!!!editted edit, it looks like there is a diff to the shape of the roto, one is moer twisted than the other, indicating car is sitting lower at ya side, pics of car needed for inspecting flatness, M Quote Link to comment Share on other sites More sharing options...
hypoid53 Posted October 15, 2014 Author Share Posted October 15, 2014 796 wrote:3 things come to mind1, the shockers are the wrong type, , IE original roto shockers These are new GAZ supplied by the TSSC shop as being correct size for the conversion bracket. 2, the actuall shocker has a fault, I have a pair, and the car developed a nok frae,t passenger side.was found to be shocker its self, banging frae inside its self. The same problem arose with the Konis fitted previously 3, ye say, ......To lessen the banging they are currently on setting 9 out of 12 which is a bit hard! I agree there is a condition called shocker pull doon, ie, the shockers settings for fliud flow, are strang,r than the springs deflection rate, so as yer going along, the car slowly gets lower and lower, till it bottoms oot.thats why springs need to be matched to damper I am going to talk to GAZ about that. Will try the Konis again. try it on other side, see if it still noks,if it noks on other side, then its shocker.still sitting low on one side at rest, then maybe front springs are weak, set wrong,or chassis twist,or maybe even the VL threads are coming oot the trunnion, lowering that side only Everything is sitting flat and square and floor to top mount measurements are identical try and show a pic of underneath cr showing full length of car, so can see if car is actually sitting flatif left front is doon, then right rear will be up, and vice veraedit, is the car got a lowering block in it ,!!!! No block, and new canley spring just fitted. Sits well on the road and looks 'right'. M Quote Link to comment Share on other sites More sharing options...
hypoid53 Posted October 15, 2014 Author Share Posted October 15, 2014 Quote:pics of car needed for inspecting flatness, Quote Link to comment Share on other sites More sharing options...
DougBGT6 Posted October 15, 2014 Share Posted October 15, 2014 You haven't mentioned if you've lowered the suspension but it's certainly low. Too low? Particularly on the front, maybe an optical illusion but it looks nose down, the bottom of the car doesn't seem parallel to the road. Quote Link to comment Share on other sites More sharing options...
WIMPUS Posted October 15, 2014 Share Posted October 15, 2014 9077 wrote:You haven't mentioned if you've lowered the suspension but it's certainly low. Too low? Particularly on the front, maybe an optical illusion but it looks nose down, the bottom of the car doesn't seem parallel to the road.Seems to be the same as my spitfire .. Quote Link to comment Share on other sites More sharing options...
hypoid53 Posted October 15, 2014 Author Share Posted October 15, 2014 Here are some comparative measurements:-top shock to ground : passenger 608mm : driver 614mmThen jacked up level with wheels off:- bottom shock to ground: passenger 288mm: driver 298mmtop to bottom shock mounts passenger 328 driver 328inner wishbone to ground: passenger 360mm :driver 365mmwishbone (u/r) to ground: passenger 242mm :driver 252mmSo nothing seems awry there.I have spoken to GAZ and they say it must be the mounting points: but these measurements show them to be within 10mm tolerance.The front has Moss TT4701 springs and Gaz adjustables. Not an intentional lowering as such, just the weight of that engine! Quote Link to comment Share on other sites More sharing options...
hypoid53 Posted October 16, 2014 Author Share Posted October 16, 2014 Here is a photo (taken early in the rebuild) of my mounting extension brackets as fitted (from Chic Doig incidentally). How do they compare with other brackets available. To get more shock travel the top fixing eye for the shock could be arced a little higher. What has everyone else got fitted? Quote Link to comment Share on other sites More sharing options...
Clive Posted October 16, 2014 Share Posted October 16, 2014 There is a thread somewhere about using the mini shocks, Konis in the threads case.But are the gaz shocks the same in terms of open and closed lengths? Just because they are supplied for a purpose, they may not actually be correct? And I believe the TSC also sell the top conversion bracket. It may be different to Chics? And have you asked Chic which dampers to use?I know I am answering questions with more questions, but it seems to be the shocks closed length is just too long..... Quote Link to comment Share on other sites More sharing options...
hypoid53 Posted October 16, 2014 Author Share Posted October 16, 2014 The car originally had Koni 18-1717 shocks (Mini Cooper) but one was defective.The TSSC GAZ ones are 'specials' and are 8.5/8" closed 12.125" open which closely matches the Konis. They are based on the GAZ GT4-2270. I would like to see some other brackets for comparison as this LH banging is apparently common to the GT6 with these brackets.If the shock is still bottoming out then the shock mounts needs to be made further apart surely?The top mount is the most likely suspect in my opinion. Quote Link to comment Share on other sites More sharing options...
John Bonnett Posted October 16, 2014 Share Posted October 16, 2014 If the knock happened on the same side with the AVOs does this not point to something else being the problem rather than the dampers? If the bump stops are sound there should be no metallic knock when the limit of travel is reached more a firm bump. Just my thought. Quote Link to comment Share on other sites More sharing options...
hypoid53 Posted October 16, 2014 Author Share Posted October 16, 2014 No bump stops on the bracket conversion John. You lose that when you remove the wheel arch mounting plates. Quote Link to comment Share on other sites More sharing options...
John Bonnett Posted October 16, 2014 Share Posted October 16, 2014 hypoid53 wrote:No bump stops on the bracket conversion John. You lose that when you remove the wheel arch mounting plates.I think there should be an internal bump stop in the damper unit Quote Link to comment Share on other sites More sharing options...
daedalusminos Posted October 16, 2014 Share Posted October 16, 2014 Are you sure the outside of the top damper 'eyelet' isn't contacting the bracket conversion? Quote Link to comment Share on other sites More sharing options...
hypoid53 Posted October 16, 2014 Author Share Posted October 16, 2014 Might have solved this.The shocks should be 2270 but are actually 2273 which is the STANDARD rotoflex shock and is 9.5" closed 14" open. So thats why they are bottoming out. Replacement 2270 shocks now being ordered. Through a simple error in ordering and thinking they were 2270's the very condition that was to be alleviated was actually reproduced. DOH ??) Quote Link to comment Share on other sites More sharing options...
GT6 M Posted October 16, 2014 Share Posted October 16, 2014 3 things come to mind1, the shockers are the wrong type, , IE original roto shockersI thought this at first,common mistake by folk no in the no.when ye get the new shockers, take off the cover, and see just where they are sittingM Quote Link to comment Share on other sites More sharing options...
.thumb.jpeg.b15b81ef10abeea1c3039ae03c4a9f3a.jpeg)
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.