Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: oscarfish on 14 May 2010, 17:33:29

Title: Left hand tracking drift and Decceleration rumble
Post by: oscarfish on 14 May 2010, 17:33:29
Hello everyone.

I have recently purchased an 04 plate Omega 2.2GLS, manual, 49,000 on the clock, 1 owners and full service history.

The car was recently serviced, but I put it into ATS to get the wheels balanced and tracking done. All four wheels were balanced and front and rear tracking done. However, the car still pulls slightly to the left, im aware of how camber affects it etc, but ATS stated they couldnt get it to run completely straight. It is only a slight drift to the LHS, but a definite and consistent thing.

Also, the car has a rumble when deccelerating (not breaking) down from 50mph to 40mph. It is a low throaty rumble, nothing that sounds "broken or wrong", more like an unbalanced sound. It does this with the clutch in or out, braking or not breaking. The only thought I have had are an unbalanced prop.

I have taken it to a local mechanic I trust and they have done the following:

1) swapped wheels front to back and side to side - no effect on either problem
2) checked all wheel bearings - no effect on either problem
3) checked for warped disks etc - no effect on either problem
4) checked all is as it should be and the car has been in a smash
5) checked the prop shaft couplings etc - no problem

The only thing we can think is an unbalanced prop, or dodgy centre bearing (although on inspection it seems fine).

Can anybody offer advice on either the tracking or vibration issue?.

Thanks

Rich
Title: Re: Left hand tracking drift and Decceleration rumble
Post by: feeutfo on 14 May 2010, 18:46:42
first off tracking on its own is a waste of time on the omega, it needs full geomotric set up, which given your new tyres you need to act fast before the cars current set up wears them ireparably causing a pull for the rest of thier life.

Where are you in the world? we can advise on where to send you for this service. But wheels in motion in Chesham is set up meka.

usual procedure is rectify any suspension faults such as wishbone bushes, stearing idler, track rod ends, broken springs or leaking shocks. Visit wheels in motion. Then fit new tyres.

Oh, and welcome to the forum by the way. :y
Title: Re: Left hand tracking drift and Decceleration rumble
Post by: Martin_1962 on 14 May 2010, 19:37:46
If it is following the road camber - I am not sure if it is a problem.
Title: Re: Left hand tracking drift and Decceleration rumble
Post by: oscarfish on 14 May 2010, 20:46:32
Thanks people.

The tyres are Pirelli P6000 all round but only have a few thousand left in them. The wear is even on all 4 and nothing seems out of the ordinary. I'm in Ely in Cambs, there's a Vauxhall dealer nearby, apart from the obvious they should be able to rectify any tracking issue shouldn't they?. I'm not sure if I'm just being picky, it's a clean car, even with genuine GM exhaust.

Anyone got any thoughts on the rumble?, I can only think it's a resonance (harmonic) on the prop shaft at a certain speed when not under load.  :-?
Title: Re: Left hand tracking drift and Decceleration rumble
Post by: feeutfo on 14 May 2010, 21:29:58
ffs dont take it to the dealer, EVER.

As said, WHEELS IN MOTION.
Title: Re: Left hand tracking drift and Decceleration rumble
Post by: Turk on 14 May 2010, 22:30:14
As Chrisgixer says, avoid main dealers/stealers as much as possible. 
If WIM is too far, ask at a local crash/body repair centre. Basically anywhere reputable that has full geometric set up capabitity. Some may even use WIM's settings.
Title: Re: Left hand tracking drift and Decceleration rumble
Post by: mic_k on 14 May 2010, 23:13:38
Ely isn't that far from WIM, it's just 95 miles each way.
 I've had 140 with makes 280 round trip. still worth it  :y
Title: Re: Left hand tracking drift and Decceleration rumble
Post by: Turk on 15 May 2010, 00:40:02
Quote
Ely isn't that far from WIM, it's just 95 miles each way.
 I've had 140 with makes 280 round trip. still worth it  :y
[/highlight]
Mine was a 400 mile round trip, just before last Crimbo.  :y
Title: Re: Left hand tracking drift and Decceleration rumble
Post by: feeutfo on 15 May 2010, 08:25:55
so with the noise your getting, is it purely road speed related?

or only when decelerating between 40 to 50?(edit, or even from 50-40 ::) ;D) if the later i guess if you where to roll down to 45 mph, in range of the noise, and then accelerate again the noise would go instantly? No idea what would cause that tbh, just curious.
Title: Re: Left hand tracking drift and Decceleration rumble
Post by: Andy H on 15 May 2010, 08:56:05
What condition is the differential? Is there oil dripping from the pinion seal or is there free play in the pinion bearing?

Due to the ingenious design of the gear teeth in a hypoid bevel gear the pinion tends to get pushed in or out of engagement depending on drive/overrun if the pinion bearings have any slack.

Are the splines OK on the prop shaft?