Ralph45 Posted May 23, 2022 Share Posted May 23, 2022 As aboveIts quite loud and is really noticeable when in towns at low speed when going over road repairs or other road imperfections.Is it time for new A frame bushes or possibly more ?cheers Ralph Link to comment Share on other sites More sharing options...
SM25T Posted May 23, 2022 Share Posted May 23, 2022 Watts link rod end bearings or anti roll bar ? Loose bolts on dampers or radius arms ? Loose wheel nuts ? Link to comment Share on other sites More sharing options...
7 wonders of the world Posted May 23, 2022 Share Posted May 23, 2022 Check the security of the front radius arm mounting - the one with the allen bolt hidden behind the side of the seat Link to comment Share on other sites More sharing options...
Ralph45 Posted May 23, 2022 Author Share Posted May 23, 2022 #2 SM25TMy thoughts initially the wheel nuts but they are torqued correctly and this seven doesn't have watts links or rear ARB. #3 7 WondersAre you referring to the unused hole by the seat ? I believe there are mounting position options and this car uses the other?I'm going to nut and bolt check the rear end later tonight to see if anything is amiss.The first time I heard it my initial thoughts were handbrake cables smacking the dedion tube as its very metallic sounding but there are no marks to suggest this and I have since wrapped some bike inertube around them to silence the noise with no effect. Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted May 23, 2022 Leadership Team Share Posted May 23, 2022 Check the integrity of the dedion tube ... Link to comment Share on other sites More sharing options...
Ralph45 Posted May 23, 2022 Author Share Posted May 23, 2022 SLR, I did inspect it and the only issue that I could find is some flaky powder coat next to the ns dedion ear.The rest looks really good with all the welds intact and no other powder coat loss. Link to comment Share on other sites More sharing options...
Wrightpayne Posted May 23, 2022 Share Posted May 23, 2022 Does the car have an FIA bar (with diagonal)? If yes there are (or should be) two thin headed bolts that sit above the shocks, fixing into the bottom of the FIA bar. It has been reported previously that the shocks can touch these bolt heads in a bump. This is on the imperial chassis. This area on the metric chassis was re-engineered to create more space above the shock.Ian Link to comment Share on other sites More sharing options...
Ralph45 Posted May 23, 2022 Author Share Posted May 23, 2022 Hi Ian,my car has a standard rollover bar not an FIA one.I can understand what you are saying but I don't think that's it but I'm going to have a good look in that area. Link to comment Share on other sites More sharing options...
Ivaan Posted May 24, 2022 Share Posted May 24, 2022 Get someone to grab the roll bar and give the car a good rock whilst you're laying under the back of the car. You'll either hear or feel where the movement is. Probably A frame bushes. Link to comment Share on other sites More sharing options...
Ralph45 Posted May 28, 2022 Author Share Posted May 28, 2022 UpdateI have just given Ivaan's idea a quick go and I can see visible movement between the A frame and dedion mount so pretty sure I need to order something from Cc or Redline!Thanks Ivaan. Link to comment Share on other sites More sharing options...
7 wonders of the world Posted May 29, 2022 Share Posted May 29, 2022 Whilst your under there it would be wise to check all the other points too.consider replacing with Powerflex bushes too Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted May 29, 2022 Share Posted May 29, 2022 If you use the Powerflex centre deDion bushing (https://www.demon-tweeks.com/powerflex-dedion-a-frame-centre-bush-pfxpf8-907/), the nylon limit washers I received were a bit oversized compared with the Caterham "race washers" (https://caterhamparts.co.uk/fixings-other/1438-nylon-racing-washer-shim-175-x-32-x-1.html) and moved around a lot more, getting chewed up. I managed to destroy the Powerflex washers in 5 track days compared with about double that for the Caterham ones. I'm currently experimenting with my own reverse cone washers that fill the gap better between the 45 degree face on the A-frame ends and the deDion attachment point.Once these limit washers wear, you get clunking with any lateral load, but if the car is generally for road use, they shouldn't need replacing very often, but for track use a season is about the life limit. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted May 29, 2022 Share Posted May 29, 2022 ****Duplicate**** Link to comment Share on other sites More sharing options...
7 wonders of the world Posted May 29, 2022 Share Posted May 29, 2022 I'm looking to see it the whole area can be reworked to accommodate a spherical joint there to permit free articulation of the axle without imparting torsionally and bending loads to the A frame - seen quite a few cracked and broken.The reverse set up as used on the LA was my option but either way will require some fabrication and welding to tube and / or frame. need to look at suitable joint dimensions and work from there......its on the list Link to comment Share on other sites More sharing options...
22daz Posted June 9, 2022 Share Posted June 9, 2022 I've been hunting a very similar noise on my car for a while. Exactly the same situation where if one rear wheel hits a bump it is silent. If both drop together like when there is a rut across the road, it clunks like something is badly loose. I've removed hood sticks, checked all bolts, replaced the ARB droplinks, seats, headrests, cable tied everything, sorted the boot floor, you name it..The other day I tightened the two long threaded bars that hold the fuel tank in place approximately another 5mm. I haven't heard it since. I'm too skeptical to say I've found it after so much effort searching, but I didn't hear it once the last time out whereas normally I would hear it 5 or 6 times on a run. Thought it was probably worth a mention. 22daz Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted June 9, 2022 Member Share Posted June 9, 2022 "The other day I tightened the two long threaded bars that hold the fuel tank in place approximately another 5mm. I haven't heard it since. I'm too skeptical to say I've found it after so much effort searching, but I didn't hear it once the last time out whereas normally I would hear it 5 or 6 times on a run."Very interesting.To remove the (admirable) skepticism... how about backing them off to where they were and seeing (!) if the noise recurs?Jonathan Link to comment Share on other sites More sharing options...
Ralph45 Posted June 10, 2022 Author Share Posted June 10, 2022 Thank you for this response this is something I hadn't considered.Tomorrow morning the car will be up on a fellow club members lift and this is something that will be checked,any findings will be reported back. Ralph Link to comment Share on other sites More sharing options...
Ivaan Posted June 11, 2022 Share Posted June 11, 2022 It could also be the float on the fuel sender in the tank hitting the top of the tank. Mine does it when the tank is full. Link to comment Share on other sites More sharing options...
Ralph45 Posted June 11, 2022 Author Share Posted June 11, 2022 Well we managed to get to the bottom of it after putting the car up on Chris's ramp.The A-frame bushes checked and after a closer inspection with bolt removed and A-frame dropped decided they were all OK. Then we moved on to the next possibility as suggested by 22daz and bingo,there was a loose fuel tank retaining rod allowing about 4/5mm movement of the tank.After reassembly I did about five miles on roads I know would hi light the clacking noise and all was quiet.I have just come in from a lovely sixty mile afternoon drive and it's 100% quiet now.A big thank you to 22daz for suggesting the possible fix and a huge thank you to Chris for the use of some great facilities and the cups of coffee throughout the morning.Ralph Link to comment Share on other sites More sharing options...
Wrightpayne Posted June 11, 2022 Share Posted June 11, 2022 Great result - just goes to show what a breadth of knowledge we have to share! Link to comment Share on other sites More sharing options...
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