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7 Aug 2016, 09:20 (Ref:3663965) | #26 | |
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Remove the rack and fit a Cortina steering box, job done.
Just don't expect any precision when cornering! |
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7 Aug 2016, 12:19 (Ref:3663980) | #27 | |||
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Thought I was on to something his morn. Dropped the ARB clamps and found the bushes were soft and shagged. (Not renewed when car put together, as was intending to change to double width mounts.) Fitted new hard rubber bushes (double width ones, but fit OK), and ran the car up the road. Atrocious shake again!!!! How can it all have changed.......... |
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7 Aug 2016, 15:11 (Ref:3663994) | #28 | |||
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Mike:
From your opening post: Quote:
Steering shimmy exacerbated by a tyre change... Logically: it is a dynamic rotating mass problem; i.e. wheel, tyre, brake disk and hub. How long have you owned and driven the car; was the shimmy always there and so excessive? If not (logic again) what's new? What has changed? BTW: do you have a tie bar between both upper strut mounts? |
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7 Aug 2016, 15:27 (Ref:3663998) | #29 | ||
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Have you had anyone else look at it, a second pair of eyes often works wonders.
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7 Aug 2016, 17:44 (Ref:3664027) | #30 | |||
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Yes, it feels like rotating mass problem. Going to search out somewhere that does on car balance...... No strut brace fitted, shell is seam welded and has all usual gussets etc. Don't use a brace on my Gp2 car either, and never had problems with that. Tim, the only eyes around on the weekend are mine! |
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7 Aug 2016, 18:05 (Ref:3664028) | #31 | |
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Mike,
Bear in mind I know nothing .... Apart from the odd steering shimmy - usually down to balance or tyre wear - on my own Fords in the early 70s the only major problem I can recall was a Escort Van that, from new, had a tendency to pull strongly left or right under braking. We were half way through Ford's 40 step warranty fix process when I wore out the rear tyres (by running them at high pressure for full load conditions all the time as it also made roundabouts more interesting, especially in the wet). At that point the original Pirellis were changed for Goodyears and the problem disappeared never to return in the subsequent 60k or so miles that I was around to use it. We had swapped the original tyres around during the initial investigation so I don't think it was a duff tyre - but seemed to be tyre related. Did I understand correctly that the problem was much worse with stickier tyres? (I have no feel for the performance of the different tyres so no idea if they are significantly different.) Have you had a look at the back end? Could something wrong there - or in the drive train/Engine mount stuff - end up inducing apparent steering shake under certain conditions with certain camber and toe in adjustments? Final suggestion .... it's possessed. You need a priest to exorcise it. See, I told you I know nothing. |
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7 Aug 2016, 18:45 (Ref:3664036) | #32 | |
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Mike, can you get someone to track you on the dual carriageway(at a suitably quiet time of day!) just to watch what the fronts are doing when you get the vibration? If a damper is shagged any wheel imbalance could cause severe pogo-ing of the wheel. Just a thought before you start spending money.
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7 Aug 2016, 20:40 (Ref:3664071) | #33 | ||
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Quote:
Maybe a suitably mounted phone camera - but if the vibration is really bad the results might only be good enough to tell you you must have a really bad vibration ... ETA: Obviously the historically correct way to make this check is to have someone hanging on to the bonnet and watching the wheels as you drive the car at racing speeds around the local roads. This would clearly give you yet another expert opinion to work with but, in this risk averse age, might attract some criticism from Health and Safety. However with a hi-viz jacket, safety hat and some form of harness I think you might get away with it. Identifying the problem would not be guaranteed. If it is clearly evident at even low speed how about taking it to an MOT station (or wherever) and sticking it on a rolling road to see what happens. If all else fails there is always eBay ... Last edited by grantp; 7 Aug 2016 at 20:52. |
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8 Aug 2016, 05:10 (Ref:3664238) | #34 | ||
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I don't have an external camera mount- it would have to be good to avoid being shaken off! However, I am going to mount my Sony HDR in usual place on the cage to record the steering wheel movement.
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8 Aug 2016, 07:10 (Ref:3664255) | #35 | ||
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Make sure that the gearbox mount is ok, I know you might think WTF has that got to do with it, but once a slight wobble starts for what ever reason it can start a serious vibration with the weight of the engine and gearbox !
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Balls of steel (knob of butter) They're Asking For Larkins. ( Proper beer) not you're Eurofizz crap. Hace más calor en España. Me han conocido a hablar un montón cojones! Send any cheques and cash to PO box 1 Lagos Nigeria Africa ! |
8 Aug 2016, 09:02 (Ref:3664281) | #36 | ||
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SOLVED!!! Collapsed inner TCA bush......
BTW on car balancers are a thing of the past, it would appear. Guess with modern geometry not so necessary..... New bushes on order! |
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8 Aug 2016, 09:14 (Ref:3664289) | #37 | |||
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Quote:
The average tyre shop will not do this: however, believe me, dynamic balance of the rotating mass can be critical. More so with very wide single seater rims and slicks. http://www.zetamak.com/detay_en_18_w...-balancer.html And of course, one must balance each tyre-rim set for a specified wheels; and mark the relative stud position. Plus ditto for wets and intermediates. |
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8 Aug 2016, 09:41 (Ref:3664296) | #38 | ||
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Balls of steel (knob of butter) They're Asking For Larkins. ( Proper beer) not you're Eurofizz crap. Hace más calor en España. Me han conocido a hablar un montón cojones! Send any cheques and cash to PO box 1 Lagos Nigeria Africa ! |
8 Aug 2016, 09:43 (Ref:3664297) | #39 | ||
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Zetamak appear to be in Turkey- maybe they have more need for such machines.... Although no one around here has one, seems still a need for such equipment on classic cars. Perhaps I need to start a new venture!
TBH, but as all the bushes are poly and recent, didn't think the inner would be ****ed already! Was more worried about the outer ball joint. Have gone for the 'even more expensive' bushes, this time. Being Gp1 spherical bearings not an option...... |
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8 Aug 2016, 09:53 (Ref:3664298) | #40 | ||
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Yes, I think I would! One of the people we (me and Motorbitz next door) phoned this morn looking for an on car balancer related that many years ago he had an RS2 with steering shake, and that it turned out to be inner TCA bushes. i took a video of the symptoms but tenths doesn't want to post a link to it, due to security issue......
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8 Aug 2016, 10:55 (Ref:3664306) | #41 | ||
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Quote:
Pre-drive check list. Check Oil Check water Check Tyre pressures. Check fuel level Change inner TCA bushes .... |
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8 Aug 2016, 11:01 (Ref:3664308) | #42 | ||
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Fair point - problem found but cause not? Why did a new TCA bush give up the ghost after so little use? Crap bush or something causing it to wear excessively?
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8 Aug 2016, 11:32 (Ref:3664312) | #43 | |||
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Quote:
Back in the 1960s many will remember MKI Lotus Cortinas on tight bends (Bottom at Brands was the classic!) and pilots such as Jim Clark, Jack Sears et al, powering into the next bot thru the bend with the inner wheel er, sort of floating in the ether? Cause: on the sideways thrust developed at speed, the bearing inside the McFearful strut simply gave up and locked as it was pushed sideways. Henry's quaintly described "Service Fix" (all problems in use needing a quick - and cheap! - solution, were called "Service Fixes"!) was to produce the bearings with conical faces. Did wonders for the surface the strut bearing, well bore on! Perhaps the best two service fixes were: 1. All affected passenger cars: squeaking from underpan bodywork in service. Cause; poor spot welds in production. Service Fix: spray Adsil Silicone on the offending joints, in order they well, squeaked silently! 2. Rear Axle outer wheel bearing rotating in housing ruining oil seals and if left, bearing housing at axle end. Making nasty rear-end noises on cornering. Service Fix: fit new wheel bearing and seal: press bearing in with copious amounts of the new wonder drug, Locktite! Working for a while in the passenger car and Tech Service, warranty and policy division, Ford Europe was much of an eye opener. If one possessed much of an engineering and sensitive spirit, after a month it had to placed neatly in cold storage. |
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8 Aug 2016, 11:50 (Ref:3664317) | #44 | ||
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Must have been the excessive sideways angles you achieved when reliving your rallying past as per your excellent new profile pic IMHO the buyer has bought a very well put together car that was a privilege to drive, enjoy! |
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8 Aug 2016, 11:55 (Ref:3664319) | #45 | ||
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It was all right up to the end of the race, and looking back over last few days, I now realise it got worse every time I jacked the car up to look for the problem....
Shite quality bushes, probably. Will be interesting to see what's left of them, and if other side is still perfect! |
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8 Aug 2016, 18:38 (Ref:3664413) | #46 | ||
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Just a thought.
In racing circles, henceforth Mike should be known as "Shimmy" Bell. |
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8 Aug 2016, 18:45 (Ref:3664414) | #47 | ||
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Problem Solved?
Oh! Goodie, now we can put this decidedly shaky thread to bed, I could not bear any more as I am bushed from reading it. |
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8 Aug 2016, 18:59 (Ref:3664417) | #48 | |||
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Bob- 46 posts in 4 days, so at least the thread got people talking! Anyway, as Gordon observed, not cured until new bushes fitted and car tested again. Who knows, could be another 4 pages of pain for you yet...... |
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9 Aug 2016, 03:37 (Ref:3664494) | #49 | ||
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Well,just for Bob you could describe,in detail,about how you renewed the bushes Mike.
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9 Aug 2016, 05:29 (Ref:3664504) | #50 | ||
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