Annoying Vibration

[nick Godridge]

Hi all, Please let me know your suggestions relating to an annoying and persistant vibration on my MK1V. First off,the car is a very early Build from 1984, and I am told by those that know that it has Mk3 front suspension.
   The vibration is most noticeable at around 2,200 rpm in 5th, so between 70-80m.p.h the sweet cruise spot!
   I have had the car up on a ramp and checked professionally for steering and suspension faults,- none found.  The front wheels were balanced around 1500miles ago when new front shocks were fitted.
   So, I am at a loss as to where the problem may lie.
   What do you guys think?
   
   Nick G

[Flyinghorse]

Nick,
   I would suspect rotating parts that can wear. Have you checked the prop & outboard drive shafts & UJ's?
   
   Other area to check would be the brakes-are they all free rotating & not binding.
   I assume tyre pressures are good allround and wheels are not warped. (Powder coating heat can do this)
   You just have to keep hunting & eliminating as it has to be something!
   
   Has your clutch been replaced

[nick Godridge]

Thx for your ideas. The vibration appears to be coming from the front off side quarter, but that could be illusory I suppose. Will work through your suggestion.
   The clutch is almost new, uses a Tilton hydraulic actuator within the bell housing. I hope we don't have to search that far!
   
   Nick
   
   

quote:Originally posted by Flyinghorse
   
Nick,
   I would suspect rotating parts that can wear. Have you checked the prop & outboard drive shafts & UJ's?
   
   Other area to check would be the brakes-are they all free rotating & not binding.
   I assume tyre pressures are good allround and wheels are not warped. (Powder coating heat can do this)
   You just have to keep hunting & eliminating as it has to be something!
   
   Has your clutch been replaced
   

[Flyinghorse]

I would swap front wheels over & see if the problem moves with the wheel.
   The other thing to watch for is the spring perch. I dont know about Mk Iv's but my CRS run's shorter springs and these can be loose when jacked up (ie not in compression) so often the retainers are RTV'd in to stop the assembly coming apart.
   
   Graham

[nikbj68]

I would start with getting the wheels checked for balance again as you could have lost a weight, and it`s quick 'n' easy!

[nick Godridge]

Thx again, Flyinghorse, I'll put those two one on the list of things to try out.
   
   Nickjb68, A sensible suggestion, and, like you say, easy and quick.
   
   I should have thought of the two simpler suggestions myself. maybe I'm trying to think too complicated!
   
   Nick
   
   !

quote:Originally posted by Flyinghorse
   
I would swap front wheels over & see if the problem moves with the wheel.
   The other thing to watch for is the spring perch. I dont know about Mk Iv's but my CRS run's shorter springs and these can be loose when jacked up (ie not in compression) so often the retainers are RTV'd in to stop the assembly coming apart.
   
   Graham
   

[CRS9505]

Not at all Nick, like the rest of us,just making mental provision for the potential bills to come![]

[shep]

Hi Nick, It happens to the best of us! I have a BMW 3 series everyday car, and it developed that familiar wheel bearing droning at 60 mph. We traced it to the front right, and ordered up the bearing and fitted it. On road testing the car after, total misery as the noise remained! We swapped the front and rear wheels, on that side, and bingo, the noise moved to the back. When we examined the tyres, the tread bocks on the inner edge had worn more at the back than the front making them slightly wedge shaped. Whilst not visible to a casual look, it was enough to cause the noise. This is not likely to be your problem, but it goes to show how we can all be wrong footed! If possible I would do as already suggested, and swap the wheels around to see if the vibration travels with a particular wheel. If not, then the focus can change to the rotating components, hubs and brake discs all round, and the drive shafts, diff, prop shaft, clutch, flywheel and eventually engine. We all love a challenge! Anyone want a perfectly good but used wheel bearing?

[MkIV Lux]

Hi Nick,
   
   Two other rather less common sources of vibration/noise that I had experienced myself:
   - water inside a tyre (this should be noticed at the latest when a proper balancing is being made; so better be present to chek as it is done)
   - a loose bolt of screw floating in its base without untying enterely, the vibration or resonance being amplified more or less depending on its location
   
   Constant

[jbottini]

On my ex MKIV( now French Frie), I experienced similar issue. Turned out to be a passenger side front wheel bearing failure. This was after two or three rebalances of all four wheels( no rotation front to rear as tires were staggered in size). When all is correct there should be zero vibration, wheel wiggle etc in these cars.

[Flyinghorse]

The Tyre itself could be a culprit. We do leave our cars sitting over the winter,often in the same spot and if a tyre had gone flat/been under inflated it may be out of round at the floor contact point.
   
   Graham

[nick Godridge]

Thx to all  of you who have responded to this query.

[jbottini]

Typically  the flat spotting associated witha tire that has one or more nylon or rayon belts will disappear when tire warms up.tires without those belts may flat spot over excessive time of no movement...drive it more or put on stands for storage

[ak1234]

.... all are good suggestions ... my experience with a vibration of my car was lack of grease.  I found the rear bearings, fron bearings and all the u joints had a minor amount of grease ... basically nothing was greased from the factory when assembled.
   
   My 2 cents.
   
   Ron