NevSpit Posted February 14, 2015 Report Share Posted February 14, 2015 Spitfire Mk4 1971 O/D I have all of a sudden developed a vibration from the rear of the car (was fine on the outward leg of a journey but seemed to appear on the way home the same day) at around 45 mph and over. I have admittedly not taken it much over that as it does not appear to go away. It is not engine speed related as the problem still occurs at the same road speed irrespective of gear. I have swapped the wheels front to back and the problem still persists. Having trawled through a small portion of the web the symptoms seem to point to the prop shaft so off to the garage this morning to extract it. Any tips on removal or is it simply a case of removing the nuts / bolts and dropping it down? It is a non sliding one prop and when I had to drop the front end to replace the overdrive last year it was not that simple given part of the OD output protruded into the prop. Hopefully the back end is 'flat' so that will just drop down and give me the movement to take the front off - if you follow me. Any other tips or pointers to look for whilst I am under the car or indeed once the prop is off would be most welcome! Cheers. Paul. Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 14, 2015 Report Share Posted February 14, 2015 there has to be some telescope effect be it a slide or strapped coupling propshaft vibration is rapid, its same speed as engine in top gear , so vibration is high frequecy, most likely is one of the drive shaft UJ has failed or has some joint float, this is road wheel speed and can be worse on cornering can make some awfull vibrations as the cross pin moves in the journals... get a pry bar you dont want any shift in the cross pin do this with the wheels at road height , ie jack up on stands but support the wheels. Pete Link to comment Share on other sites More sharing options...
NevSpit Posted February 14, 2015 Author Report Share Posted February 14, 2015 Thanks for the pointer Pete which is appreciated, but for the purposes of clarity (you can tell I am no expert in these things) which bit do you mean on this diagram :-) Link to comment Share on other sites More sharing options...
dougbgt6 Posted February 14, 2015 Report Share Posted February 14, 2015 The Universal joint is in the "dotted box" on the diagram it's labelled GUJ115. They're quite cheap, around £10. If it was me I'd do both sides even if the other side seems OK. It's quite an easy job, I remember doing one on the road under the Hammersmith flyover! Link to comment Share on other sites More sharing options...
Eddie Posted February 14, 2015 Report Share Posted February 14, 2015 This interests me because although I do not get the vibration, the rear of my Herald is noisy above 45mph. I had assumed it was a worn diff or worn bearings in the diff and have been trying to pluck up the courage to remove it for reconditioning. Would it be worth changing the UJs first, in case that is the problem rather than the diff itself? Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 14, 2015 Report Share Posted February 14, 2015 There some simple clues about how to on bills www.rarebits4classics..co.uk the drive shaft universal can make some unbelivable noises and vibrations its less problem on rotaflex but on spit herald mk1 vitesse and gt6 this little unit takes awhole lot of load as it rotates the journals on the crosspin must not have any lift or end float the caps under the circlips must be a neat tight fit, a prposhaft is self centres and less of a problem thicker circlips are about to make these little sods a neat fit You must get the shaft as in its running position and stick a strong lever through the cross pin and attempt to lever the yoke , the slightest lift will give you noise vibtration and or clicking on corners at low speed, you cab change the circlips on the car , they must ,,, reallymmust be cleaned and fully located in their shallow groove believe me you dont want one to pop out on test got that Tee shirt. Bearing caps can and often pitch and jam it goes with the job , never force a new cap , if it stops when pressing in then you probably have a needle roller dropped out , stop look start again pete Link to comment Share on other sites More sharing options...
KevinR Posted February 14, 2015 Report Share Posted February 14, 2015 A propshaft U/J can suddenly go from being "tolerable" to shaking the car apart in a few hundred miles, and the vibration can be very severe. It's well worth jacking the car up and checking the to see if one has failed - probably the rear one. Relatively easy repair, although it may be easier to buy a new (balanced) prop shaft and fit that - less phaffing with the bearing caps. Link to comment Share on other sites More sharing options...
NevSpit Posted February 21, 2015 Author Report Share Posted February 21, 2015 Brief update, driveshafts looked ok as far as I could tell (that's not to say they are guilt free at this stage) so extracted the props shaft - after the swear box was suitably topped up removing the rear nuts / bolts... Looking at the rear UJ it was 'sticking' on one plane so a replacement UJ was sourced. Once on the workbench I used the over and under sized socket plus big hammer method and after quite some persuasion managed to separate everything and this is what it looked like: As can be seen three sides are shiny and one is not and this is what the a couple of the caps look like: Now, the one on the right I may have mangled more than it was in trying to get it out but as for the needle rollers I have no idea where they are (and yes that was on the 'dull' side of the UJ). It was not loose when it was on the prop and I have not found them on the workbench or floor so no idea what happened there. Hopefully this is the cause of my problems but if not then it needed doing anyway! Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 22, 2015 Report Share Posted February 22, 2015 Think you have nailed your vibro There is a gremlin with classic repairs when you have a problem and find the culprit Once repaired you find the problem still exists many have this Tee shirt, It can haunt the best intentions thers often 40/50 years of ghosts determined to win ha pete Link to comment Share on other sites More sharing options...
mishmosh Posted February 22, 2015 Report Share Posted February 22, 2015 Good work. Ujs are a pet hate. Prob caused by owning heralds ! Link to comment Share on other sites More sharing options...
KevinR Posted February 22, 2015 Report Share Posted February 22, 2015 Now where have a seen a rear prop shaft U/J that looked exactly the same as yours ? Link to comment Share on other sites More sharing options...
Colin Lindsay Posted March 4, 2015 Report Share Posted March 4, 2015 Pesky little beggars, aren’t they? Link to comment Share on other sites More sharing options...
NevSpit Posted April 19, 2015 Author Report Share Posted April 19, 2015 Just by way of closure it worked!! I was fairly confident given the condition of the old UJ but you can never be certain that there is not some other dark force at play... I know it has been a while since I raised the original thread but there have been demands of everyday life to deal with and whilst the car was up I sorted out the other jobs I had been meaning to do such as painting the floor / chassis, a healthy dose of cavity wax, greasing, trunnion oiling, painting the exhaust with VHT paint (now that does smell when it cures!) etc. I'm ready now for some more sunshine! Link to comment Share on other sites More sharing options...
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