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Nigel Ralph
Unregistered guest
Posted From: 203.87.65.98
Posted on Sunday, 06 March, 2005 - 21:23:   Edit PostDelete PostView Post/Check IP

I have a vibration that is progressivly evident and is worst at about 95km/h.

I have searched through the Forum's pages on vibrations but am wondering if someone may have some specific knowledge.

Thinking wheel balance/alignment etc I have replaced the front tyres and had an alignment done. I will at some time soon swap the trunnions but I am not fully certain that these are the problem.

My mechanic friend has said that he thinks it feels like the engine mounts have become compressed as the vibration as well as coming up through the seat also gives the steering wheel a bit of a shake. In other words it is a whole 'box and dice' shake.

My engine does leak a fair bit of oil. Is it possible that the oil has effected my mounts and they need replacing? Is there a simple test to see if they are OK?

(Message approved by david_gore)
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John Dare
Grand Master
Username: jgdare

Post Number: 230
Registered: 12-2004
Posted on Wednesday, 09 March, 2005 - 12:32:   Edit PostDelete PostView Post/Check IP

Hello Nigel. The trunnion swap would be a reasonable start and a changeover would do each of them good anyway. Certainly check/replace engine mounts if distended etc.(due to oil) since a sudden emergency stop can result in the fan impacting the radiator, if for whatever reason/s, they are beyond their service life.
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Patrick Lockyer.
Grand Master
Username: pat_lockyer

Post Number: 348
Registered: 9-2004
Posted on Wednesday, 09 March, 2005 - 18:26:   Edit PostDelete PostView Post/Check IP

Nigel,have just seen your posting.
In reply to your question it is in my opinon that there could be all sorts of manner of things to suggest.
Before i would like to comment on the above i would first like to know more about the car.
Is the ride hight working and at its correct setting.
Has the car been in daily use.
Has the vibration come to your notice suddenly progresing steadly worse.
Have the rear wheels been balanced on off the car.
Does the engine run Ok
How manny miles has the car traveled.
Do you get any worst vibration on brakeing.
Have you had any work carried out on the prop uj's
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GabriŽl Viljoen
Prolific User
Username: gabriel

Post Number: 32
Registered: 3-2004
Posted on Wednesday, 09 March, 2005 - 21:31:   Edit PostDelete PostView Post/Check IP

Same Problem with my 1971 Shadow.

At first it started to vibrate at about 130 km/h and when the engine is under load, like an uphill. I had the engine rebuilt. The ride height adjusted - I think it might be a tiny bit high at the moment. The engine mountings were replaced. I swopped the half shalfts. The universal joints were checked and greased. Wheels balanced and aligned. The vibration is now starting at about 90 km/h.

What I will try next is to balance the driving shaft. I am also going to swop my tyres with a car that does not have this problem to rule out the tyre issue.

What I did notice when I had someone to drive the car and I followed in another vehicle is that the grooves on the left hand side tyre is visible when the car is driven, but the right hand side is blurry. I think the wheel has a slight wobble to it.

Any suggestions would be most welcome.

Kind regards

Gabriel Viljoen
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Nigel Ralph
Unregistered guest
Posted From: 203.87.57.151
Posted on Thursday, 10 March, 2005 - 21:12:   Edit PostDelete PostView Post/Check IP

Hi Patrick,

I have had reconditioned accumulators installed - I tried to do this but my mechanic friend got fed up with the time I was taking to undo nuts in tight awkward places so he did it. I am full of admiration for professionals who really show one up as an amateur. Pressure switches redone - these were causing the major problem. Height control valves redone, one with genuine o-rings and one with regular oil resistent o-rings. (Huge difference in cost and shall see if there's a huge difference in life span).

I had previously replaced the springs and the car sat slightly higher than recommended but there was no vibration when driving. This has only come since the height control valves were redone. I am toying with the idea of adding a steel plate to the boot for additional weight. (Archives showed one of the Canberra people to have done this some years ago).

As soon as the height control valves were redone some strange noises came from the rear. 1 squealching type noise sometimes like whales talking. 2 A terrible metal tearing type noise over road bumps.

I drive the car daily and there is no on-car balancing facility in the Whitsundays. The engine is fine though aged and blows a bit of smoke. The valves were redone prior to my purchase but obviously rings have not been touched. Have recently had a complete repaint and have redone the woodwork. Now looks a treat.

Engine block has a slight coolent leak and I have got some stuff from Robert Chapman to put in the radiator. Oil leaks very slowly from everywhere and my next major project in a year or so is rings and bearings. This should fix most of this.

There has been no work done on prop ujs. The problem arose immediately after the height control valve work so I did not even go down that line. I shall check as coincidences do sometimes happen.


(Message approved by david_gore)
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Patrick Lockyer.
Grand Master
Username: pat_lockyer

Post Number: 358
Registered: 9-2004
Posted on Saturday, 12 March, 2005 - 19:18:   Edit PostDelete PostView Post/Check IP

Nigel, poss Gabriel! Sounds as though it is indeed the rear drive shaft trunnion wear or the shafts out of alignment as the vibration has only started since the ride hieght control valves were done.
First check to see the cars trim hieght,it is correct, checked with the sill chrome strip front and rear checking to the ground from memory 13,1/2" depending on what tyre size are used.
this is with the car running in park with some load in the car to allow for driver etc.
The important thing is that they are the same F/R. The n/s and o/s of the car should be the same.
If this is correct the shafts should both be level.
If not then adjustment to each of the ride hieght adjusters is needed and at worst the crossmember diff body mounting washers.
If due to the New springs keeping the body high then a load in the boot for a period of time may be the answer.

Regarding the reversal swopping the drive shafts i would first check for movement between the trunnion and shaft.
This must be carried out from under the car with hand brake ON, wheels chocked engine running,the shafts must be in the dead level plane "ride position".
With the car in netrual rotate the diff flange or prop backward and forward checking for movment between trunnion and drive shaft if movement is pressent then swop the shafts left to right assuming they have not been done before.