AlanT Posted February 11 Report Share Posted February 11 Hi All, I’ve got the classic +50mph shake. The sliding joint on my prop has play in it so I’m looking at new props( have already tried changing UJs). Paddock’s have them at £135 which seems low vs. getting one made. Has anyone experience with these? Thanks Alan Link to comment Share on other sites More sharing options...
johny Posted February 11 Report Share Posted February 11 My prop has play in the sliding joint but just needed straightening and balancing however dont know how the price of that will compare with a new one now. The advantage of reusing the original is that you can use quality UJs whereas I would expect any replacement to use the 6 pounds a shot ones.... 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 11 Report Share Posted February 11 the telescope can wear terribly , considering it doesn't move much must have some detrimental effect Ive only bought props from bailey & morris not used a JP unit . JP has a good reputation Pete 1 Link to comment Share on other sites More sharing options...
johny Posted February 11 Report Share Posted February 11 I think most of the spline wear occurs between its faces that transmit rotational drive rather than in a radial direction so not a major factor in prop out of balance. However I was told that prop bending is quite common although no idea how that happens! Link to comment Share on other sites More sharing options...
trigolf Posted February 12 Report Share Posted February 12 Having ruled out all other causes of vibration at 50+mph( wheels,diff mounts,gbox mounts, driveshafts etc), I bought a new prop for my OD Vit last year from Bailey Morris. Cost £300.00.😟 Looked like a nice job, but when fitted I noticed a small amount of play in the sIiding joint and still had vibration! So back it went for a rebalance. They also replaced the sliding jt . Fitted prop again, still had vibration! 😡I ended up taking the car to Vibration Free Services in Bicester. They put it on the ramp and ran her up. After a lot of testing,they measured 28 microns out of balance at the diff end, IIRC. They did'nt want to disturb the welded weight already on the prop, so eventually fitted 2 jubilee clips and that figure came down to 3 microns. This process took about 3 hours of test, adjust weight posn and orientation,measure again + a couple of road tests. Car now drives fine. I've never really understood why some Vits seemingly don't suffer from prop vibration at all, and others do. Are convertibles more prone? Are Mk2's ( mine) more prone? Does the extra weight of roto wishbone, and cast v links increase the likelyhood? Link to comment Share on other sites More sharing options...
johny Posted February 12 Report Share Posted February 12 Wow I know vibration is an extremely complicated subject with harmonics and all sorts coming into it. Some cars might just resonate at a certain frequency so making a small amount of vibration, which on another car would be no problem, worse. In your case I think youve got to pray that you never need to replace a prop UJ or even dismount the thing😨 Link to comment Share on other sites More sharing options...
trigolf Posted February 12 Report Share Posted February 12 30 minutes ago, johny said: Wow I know vibration is an extremely complicated subject with harmonics and all sorts coming into it. Some cars might just resonate at a certain frequency so making a small amount of vibration, which on another car would be no problem, worse. In your case I think youve got to pray that you never need to replace a prop UJ or even dismount the thing😨 Oh yes! Hopefully the job will see me out, before revisiting! I've Tippex marked the Jub clips relative posns etc. I think it comes back to ' just. because the shaft balances on the balancer does not necessarily mean it'll run true when fitted to the car' Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 12 Report Share Posted February 12 it is always worth checking the connecting couplings for runout and aged bruising from years of mallet ingress max runout less than 0.005" on the coupling fce and its spigot location you can do what you like with the prop but a wonky coupling means you wont succeed . Pete Link to comment Share on other sites More sharing options...
johny Posted February 12 Report Share Posted February 12 I think the prop is bolted into the balancing machine using the flanges Pete so any deformation there should show up during the process🤞 Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 12 Report Share Posted February 12 (edited) taking the prop to be balanced wont check the state of the wonky flanges on the diff and gearbox !!!! always run a file over the faces or if you can use a DTI in the face and the register diameter they are critical pete Edited February 12 by Pete Lewis 1 Link to comment Share on other sites More sharing options...
trigolf Posted February 12 Report Share Posted February 12 1 hour ago, Pete Lewis said: taking the prop to be balanced wont check the state of the wonky flanges on the diff and gearbox !!!! always run a file over the faces or if you can use a DTI in the face and the register diameter they are critical pete I agree Pete. Did all that first. No faults found with flanges. Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 12 Report Share Posted February 12 thats good Pete Link to comment Share on other sites More sharing options...
AlanT Posted February 12 Author Report Share Posted February 12 Thanks All. I think I’m going to go for a new prop. Climbing about underneath isn’t my fav activity but it will be a break from welding what has turned out to be a very rusty Morris! Link to comment Share on other sites More sharing options...
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