Monaro – Bad Vibrations

[sjr56]

I have had an infrequent and intermittent vibration problem at high speeds (80+ ish) for a number of months. Sometimes feels as though coming through the floor of the car, but no significant shake of the steering wheel. If I slowed to 60mph the noise/vibrations would slowly go away. Accelerate up to 80mph again and all is fine. On another trip no vibration problems at all. This was a mystery, and I was starting to wonder about the propshaft bearing.

However, today having not driven the car much for three weeks and not having had any time to investigate further, I got onto the motorway and accelerated to about 70mph and had very strong vibrations, this time accompanied by strong steering wheel shakes. Had to slow to about 35mph for the vibration to subside. I stopped and went around the wheels and discovered that the front right hub was extremely hot. Centre part of wheel was too hot to touch. Other three wheels were cool.

Wheel bearing problem? Sticking brake calliper? But brakes seem fine, and touching the brakes didn’t seem to affect the vibration. The tyres are good. A new set of Continental Sportcontac 5Ps was fitted about 5,000 miles ago.

I crept home at 30mph and my local trusty garage man around the corner (who services the car) is going to look at it tomorrow, but he is mystified by the story. Any ideas or suggestions of what he should look for?

Steve

[THUNDER STORM]

Look at the center prop shaft bearing, the rubber round the bearing splits, cheap enough to repair.

Ade

[sjr56]

Aden,
Yes will definitely check the prop shaft bearing. I guess that if the prop shaft is shaking it can shake the engine on its mounts, and feed into the steering. The hot front hub might be a separate issue.
Steve

[Superhans_]

Usual offenders for things like that are:
A loose wheel,
A buckled wheel,
A sticking calliper.

[Superhans_]

To get to the bottom of it you would probably want to:
Firstly check all your wheels are tight,
Secondly touch all the discs after use to see if one is melting hot compared to the rest,
Thirdly take it into a tyre shop and get all the wheels re-balanced,
Then final thing would be to take it into a garage to get the driveline looked at on a ramp.

[Boosted LS1]

Certainly could be the wheel bearings given that you felt vibration through the steering wheel.

[mfp4073]

I think you will need to take a structured approach to this problem.
As always start with the easy checks first. Check the tyres even if new, check for damage to the wheel, maybe even swap your wheels around. Don't forget to examine all the suspension and steering components.
I had a steering wheel wobble for some time and it drove me crazy. I checked every thing several times and couldn't see anything wrong. After several frustrating months I found the problem, it turned out to be a worn track rod end, even though it looked fine.

Happy hunting

John

[sjr56]

Had the car up on the lift this morning and the centre prop shaft bearing rubber mount clearly split, and largely absent! (The hot front hub must be a separate issue, which I will deal with when the prop shaft has been fixed.)

Much more worrying, I called Monkfish for advice and to order parts and discovered a recorded message saying that they closed the business on 30th August. Still selling their existing stock online, but only working to fill orders and dispatch on Wednesdays. So I ordered a refurbished prop shaft online (easier to fit than the bearing).

Who do we get parts and advice from when Monkfish have completely closed?

Steve

[mfp4073]

sjr56 said:

Had the car up on the lift this morning and the centre prop shaft bearing rubber mount clearly split, and largely absent! (The hot front hub must be a separate issue, which I will deal with when the prop shaft has been fixed.)

Much more worrying, I called Monkfish for advice and to order parts and discovered a recorded message saying that they closed the business on 30th August. Still selling their existing stock online, but only working to fill orders and dispatch on Wednesdays. So I ordered a refurbished prop shaft online (easier to fit than the bearing).

Who do we get parts and advice from when Monkfish have completely closed?

Steve

This is one of the sad things about Monkfish closing down. I have had to call them in the past for free advice and they were happy to help.
You could call Walkinshaw performance and see if they can help. They should be quite knowledgable about VXR8's and Monaro's, but I have never used them myself......yet!

John

[sjr56]

Roger at Monkfish provided a reconditioned propshaft, and it was fitted by my local garage this morning. A quick trip up to 70mph on the local bypass confirmed that the vibration has gone. Also hot front hub problem seems to have just gone away. Will keep an eye on it though.

[mfp4073]

Good result, it's aways nice to get an update for future reference.

Edited by mfp4073 on Friday 22 September 16:36

[maccavvy]

If the wheels hot... a sticking caliper is deffo on the agenda for inspection.. check pad thickness to confirm

[sjr56]

Yes, I will take the calliper off the rotor in the next few days and take a close look.
Steve

[THUNDER STORM]

I understand that if you do not change brake fluid at recommended intervals the water content can build up in the fluid and this could cause piston seizure.

Ade

[sjr56]

Yes good point, and I was thinking about that. The fluid has been changed - but I cannot quite remember when!
It must be overdue.

EDIT: Just checked the service book and the fluid is supposed to be changed every 2 years. Looks like mine hasn't been changed for five years.

Edited by sjr56 on Saturday 23 September 14:46

[vxr2010]

the reason for the change is not purely fluid based , the bleed nipples can get stuck if left too long and when they do that creates another big head ache , the funny thing about brakes as they get worse slowly you don't realise how bad they are till you actually do the fluid

[vxr2010]

the reason for the change is not purely fluid based , the bleed nipples can get stuck if left too long and when they do that creates another big head ache , the funny thing about brakes as they get worse slowly you don't realise how bad they are till you actually do the fluid

[sjr56]

Extremely disappointed!

This morning took the car on the motorway for the first time since Friday’s prop shaft swap. Got it up to 70-80mph and the vibration started to return, but not immediately. Started with a rumble under the car, which became a strong vibration and eventually started to shake the steering wheel. Had to slow to about 40mph for it to go away, but was then able to speed up to 60 with no vibration. Couldn’t go faster again because I took an exit to turn for home (naturally) and traffic then prevented any speed.

What is going on?

Is the recon prop shaft perhaps out of balance? It was unpainted, but Roger at Monkfish assured me that it had been balanced. The centre bearing assembly was clearly new.

Has the vibration already ripped out the new rubber bearing mount? And if so why? Could it be one of the ‘doughnuts’ at the prop shaft ends that is breaking up? They looked fine. Cannot get under the car to check any of this until tomorrow.

Help!

Steve

PS – Before this test drive I did check the front hub, removed the calliper and the pads, checked the pins on which the calliper ‘floats’ and put it all back together again with the magic Copper Ease grease. Wheel bearing was fine.

[THUNDER STORM]

It is defo to do with the prop shaft drive line, if it cured it, then its back. As any joint bolts not been tightened enough?

Ade

[MedwayMonaro]

I had this. Turned out it occurred after I adjusted the handbrake and was the shoes rubbing on a lip on the disc. Backing the adjuster off a bit helps but obviously need to be careful the handbrake still hold the car. It might not be this but worth a try?