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Omega Help Area => Omega General Help => Topic started by: Migv6 le Frog Fan on 19 February 2017, 20:47:11

Title: Knocking n/s/f
Post by: Migv6 le Frog Fan on 19 February 2017, 20:47:11
Quite a severe knocking when going over bumps and even when applying the brakes, from the n/s/f. I fitted new Meyle droplinks today but that hasn't cured it.
I observed there was noticeable play in the wheel bearing, question is, would that be a likely cause of these symptoms. I cant see it myself, but I may be wrong.  :-\
Title: Re: Knocking n/s/f
Post by: Elite_L0ver on 20 February 2017, 08:25:20
Following as iv same but only when turn or a little bump
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 20 February 2017, 09:44:43
The usual cause is droplinks needing replacing which is why I did that first. In my case it hasn't worked though.
I shall probably replace the wheel bearing (hub) soon anyway, and if it isn't that, then dampers and top mounts are about the only thing left to change.
Title: Re: Knocking n/s/f
Post by: Nick W on 20 February 2017, 10:13:53
You can determine if it's the wheel bearing by jacking the car and inspecting. It's unlikely to be the problem,as you would have other symptoms. Changing them just for the sake of it is daft.


Which leaves a worn out shock/top mount/bearing/rusty strut tower.


Knackered shock is where I would look next.
Title: Re: Knocking n/s/f
Post by: Elite_L0ver on 20 February 2017, 11:47:49
You can determine if it's the wheel bearing by jacking the car and inspecting. It's unlikely to be the problem,as you would have other symptoms. Changing them just for the sake of it is daft.


Which leaves a worn out shock/top mount/bearing/rusty strut tower.


Knackered shock is where I would look next.

If it was WB then you would hear a grumbleing noise would you not
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 20 February 2017, 12:33:23
You can determine if it's the wheel bearing by jacking the car and inspecting. It's unlikely to be the problem,as you would have other symptoms. Changing them just for the sake of it is daft.


Which leaves a worn out shock/top mount/bearing/rusty strut tower.


Knackered shock is where I would look next.

Definitely noticeable bearing play when pulling / pushing on top & bottom of the disc.  :y
I'm also suspecting shock. Being an elite,means its quite "floaty" anyway, so maybe not as easy to diagnose as an MV6 say.
Title: Re: Knocking n/s/f
Post by: Webby the Bear on 20 February 2017, 13:54:26
Play at 12 and 6 isn't always a bearing. If you do that and feel the top mount I bet you'll find it's that that's causing the knocking and the play. Check the nuts tight and if it is replace top mount
Title: Re: Knocking n/s/f
Post by: cam.in.head on 20 February 2017, 14:50:05
Check the rear vertical bush on the suspension arm.this can detach itself from its rubber surround
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 20 February 2017, 17:45:49
Its almost brand new, genuine GM. ;)
Title: Re: Knocking n/s/f
Post by: cam.in.head on 20 February 2017, 18:42:36
Worth a wiggle but we can probably eliminate that then !
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 01 March 2017, 11:31:20
Removed the strut this morning to see if there was anything visbly obvious, which there wasn't. Problem is I don't have any spring compressors to strip it any further, so cant ascertain if the top mount bearing is knackered or not.  :-[
Should be able to borrow some compressors soon, so can hopefully carry on with diagnosis shortly.
Title: Re: Knocking n/s/f
Post by: Elite_L0ver on 01 March 2017, 13:09:40
Iv a pair u can borrow :y
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 01 March 2017, 13:37:43
Very kind offer thanks, but Ive arranged to borrow some from a workmate.  :y
Title: Re: Knocking n/s/f
Post by: Elite_L0ver on 01 March 2017, 15:30:46
Very kind offer thanks, but Ive arranged to borrow some from a workmate.  :y

Ok buddy be interested to know what the outcome is as my steering is a little wavey n I've a knocking coming from ns also
Title: Re: Knocking n/s/f
Post by: Doctor Gollum on 01 March 2017, 15:45:24
Very kind offer thanks, but Ive arranged to borrow some from a workmate.  :y

Ok buddy be interested to know what the outcome is as my steering is a little wavey n I've a knocking coming from ns also
99/100 droplinks knocking and worn bushes... bet yours is between 80 and 120k miles old ;)
Title: Re: Knocking n/s/f
Post by: Marks DTM Calib on 01 March 2017, 16:20:14
Play at the 6-12 position could be the bottom ball joint, if its the wheel bearing it will be at every position and may reduce if the brake pedal is pressed. This type of test is useless for diagnosing top mounts as the mount is not loaded with the wheel dangling as its sat on the top hat which serves no other purpose than to stop the strut falling out the strut towers when you jack the vehicle up or launch it off something whilst on the move.

Title: Re: Knocking n/s/f
Post by: cam.in.head on 01 March 2017, 16:23:37
Its almost brand new, genuine GM. ;)
                 I thought bottom arm too but he says nearly new gm ones ?
Title: Re: Knocking n/s/f
Post by: Doctor Gollum on 01 March 2017, 16:41:00
Caliper bolts or carrier loose :-\
Title: Re: Knocking n/s/f
Post by: Kevin Wood on 01 March 2017, 16:46:09
Caliper bolts or carrier loose :-\

Good call. I had one recently where the anti-rattle spring had pinged out from under the caliper body meaning the brake pad was unsupported. Cue surprisingly loud knocking / rattling sound which disappeared under braking.
Title: Re: Knocking n/s/f
Post by: Elite_L0ver on 01 March 2017, 16:51:10
Very kind offer thanks, but Ive arranged to borrow some from a workmate.  :y

Ok buddy be interested to know what the outcome is as my steering is a little wavey n I've a knocking coming from ns also
99/100 droplinks knocking and worn bushes... bet yours is between 80 and 120k miles old ;)

88700k ish :y but i have grabbed them cannot fell any play  :y
Title: Re: Knocking n/s/f
Post by: Kevin Wood on 01 March 2017, 16:54:23
Very kind offer thanks, but Ive arranged to borrow some from a workmate.  :y

Ok buddy be interested to know what the outcome is as my steering is a little wavey n I've a knocking coming from ns also
99/100 droplinks knocking and worn bushes... bet yours is between 80 and 120k miles old ;)

88700k ish :y but i have grabbed them cannot fell any play  :y

They can be surprisingly noisy with very little play evident. Also, unless the car is completely level on its' wheels they are often under some preload from the ARB, so you can't feel the play until they are off the car.
Title: Re: Knocking n/s/f
Post by: cam.in.head on 01 March 2017, 17:43:45
Anti roll bar links should be ok now if you fitted new ones but test by standing by front door and push and pull on top above door severely !. This loads them from one extreme to the other and you should hear any noise. An assistant comes in handy here to feel.that will eliminate them.             To check wishbone bushes other than levering or pulling try having someone move car forwards whilst applying and releasing brake. Wheel should not jolt back and forward .rear bush of wishbone can be checked by jacking up under jacking point to let wheel hang free. .you should be able to see the bush and if tearing will be obvious. You say they are fairly new gm arms anyway. So after this check that will eliminate them.....strut top is possible i suppose but with weight of car bearing down on them and spring pushing up they are hard to test. Do they creak when turning ? Can you recreate the noise when stationary?  Does the noise stop when braking or get worse. . Hope this is of some help to you. Probably just repeated whet everyone else has suggested ! ,
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 01 March 2017, 18:14:34
In my case, droplinks are a week old. Bottom arms are genuine GM refurbed with new balljoints, new GM rear bushes and new polybushes at the front. Everything wishbone related seems to be exactly as it should be, and I would be surprised if it wasn't.
Only really leaves dampers or top mounts I think. They have done well in lastingWill find out when I get spring compressors and some time off work.
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 01 March 2017, 18:28:18
Having said all that - It wouldn't do any harm to check the balljoint anyway, as I could have got a duff one.
In fact I should have already done so, as to assume is to make an ass of you and me.   ::)
Title: Re: Knocking n/s/f
Post by: TheBoy on 01 March 2017, 18:32:58
its sat on the top hat which serves no other purpose than to stop the strut falling out the strut towers when ..... launch it off something whilst on the move.
So vitally important then ;D
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 01 March 2017, 18:35:11
In your case - very vital indeed.  ;D
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 09 March 2017, 15:27:07
Play at the 6-12 position could be the bottom ball joint, if its the wheel bearing it will be at every position and may reduce if the brake pedal is pressed. This type of test is useless for diagnosing top mounts as the mount is not loaded with the wheel dangling as its sat on the top hat which serves no other purpose than to stop the strut falling out the strut towers when you jack the vehicle up or launch it off something whilst on the move.

Ok, Ive just had another play. Definitely perceptible play in the wheel bearing at all positions. Pretty much disappears when brake pedal pressed.
I'm trying to narrow down the cause of the knock from this corner when going over bumps etc. without replacing everything.
To recap - ARB bushes are ok. Wishbones are GM with new GM rear bushes, new balljoints, new polybushes at the front. Brake calipers are tightly mounted.
This leaves dampers and top mounts, unless a very audible knock could be caused by the play in the wheel bearing ?
What is the best way of checking top mounts ?
If replacing dampers is I tstandard practice to replace top mounts and springs at the same time ?
I'm guessing yes for the top mounts. Springs, I'm not sure.  :-\
Tia.
Title: Re: Knocking n/s/f
Post by: cam.in.head on 09 March 2017, 15:39:01
You say anti roll bar bushes are ok ? . Do you mean droplinks ?
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 09 March 2017, 15:51:20
Sorry I missed some info ou., Rubber arb bushes are fine. New Meyle droplinks a week ago.
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 09 March 2017, 23:54:20
Any opinions ? Knock caused by play in wheel bearing, knackered dampers, or top mounts ?
Tia.
Title: Re: Knocking n/s/f
Post by: Doctor Gollum on 10 March 2017, 11:11:50
Yup ;)

Retighten everything though, especially the droplinks ;)
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 10 March 2017, 12:17:57
Will do.  :y Got plod spec front springs arriving soom which will definitely go on there. Also plod spec front dampers. If I can find a way of ascertaining if they are still  in good condition internally, hopefully without fitting them on the car to find out, they will also be going on the car.
So, need to get a pair of top mounts, then get it all fitted and get wheels aligned again. :)
I think I'm going to have to name it Triggers broom 2. So many parts renewed in less than a year of ownership. :D
Any suggestions on top mounts from the good doctor ?
Title: Re: Knocking n/s/f
Post by: Doctor Gollum on 10 March 2017, 12:40:55
Pedders heavy duty from Monkfish plus bearings...

http://www.monkfishperformance.com/info-vauxhall-monaro-cv8-57-parts

https://www.atp-autoteile.de/de/product/152445-sachs-staubschutzsatz-sto%c3%9fd%c3%a4mpfer/v-15808

https://www.atp-autoteile.de/de/product/159575-febi-bilstein-w%c3%a4lzlager-federbeinst%c3%bctzlager/v-15808

Should see the job done :y
Title: Re: Knocking n/s/f
Post by: terry paget on 12 March 2017, 21:50:23
Yup ;)

Retighten everything though, especially the droplinks ;)
Affirmative. I once changed drop links but failed to properly tighten bottom nut. That caused a knocking noise until properly tightened. With car over pit and son bouncing car fault was obvious.
Title: Re: Knocking n/s/f
Post by: cam.in.head on 14 March 2017, 19:06:14
Did you get to the bottom of this ?
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 14 March 2017, 20:04:35
Not yet. On a run of nightshifts at the moment. Got a pair of springs & dampers arriving in the near future. Will buy a pair of topmounts and bung the whole lot on there.
Its all done 175k miles, so must be past its best.
I'm pretty convinced that the damper is shagged. The front is rather bouncy now, even by Elite standards.
Car isn't used as a daily, so its not desperately urgent.
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 10 April 2017, 12:14:22
Update. I have fitted the plod spec dampers & springs along with new Pedders Monaro spec top mounts and new top mount bearings.
I cant believe how much stiffer the front of the car is now, but when I removed the old dampers it was obvious that there was very little compression damping left in them.
However, there is still a bit of knocking over bumps from the n/s/f. Not as bad as it was and not quite the same, but I'm surprised it hasn't completely gone as everything suspension & wishbone related has been changed.  :-\
Title: Re: Knocking n/s/f
Post by: Doctor Gollum on 10 April 2017, 14:00:43
Any play on the caliper?

Is the horn still securely attached?
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 10 April 2017, 14:04:15
Pretty sure calipers are fine, but may be worth another check. Hadnt thought of horn. Will have a look.  :y
Title: Re: Knocking n/s/f
Post by: Stige on 10 April 2017, 19:19:30
I just had a really noticable bang everytime I touched the brakes and a noticable "budge". The driver side outer tie rod had massive play in it causing really unsteady steering and massive knock.

Swapped it today, made everything a lot better but I still have the passenger side lower control arm rear bushing completely busted as the control arm is resting against the body causing more play and random knocking.
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 10 April 2017, 20:44:44
Tie rods are fine. Control arm bushes are new. A couple of hours ago I found the strut to steering knuckle bolts weren't as tight as they should be, so I tightened them to the spec in Haynes manual. I thought I had found the cause, but a test drive showed it is still there.  :-\
Title: Re: Knocking n/s/f
Post by: Doctor Gollum on 10 April 2017, 22:09:34
Another half turn on the drop links, just to be sure :-\
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 10 April 2017, 23:17:16
Almost gave myself a hernia doing just that earlier. When I get the chance I think I will slacken everything off again and carefully torque everything up carefully from scratch.
Title: Re: Knocking n/s/f
Post by: Doctor Gollum on 11 April 2017, 01:39:29
As a thought, have you done anything with the arb bushes? Might be worth checking the clamp bolts while you're there... Can be done from the side with a regular spanner, 13mm iirc ;)
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 11 April 2017, 03:11:34
Havent touched them but will check them  :y
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 19 April 2017, 14:46:52
Right then, just to tie this thread up. Ive been out to the car with a torque wrench and Haynes book of bollix  and checked the tightness of everything which has been disturbed recently.
Nothing was loose by any means but most things weren't tightened up to the correct torque value. I tightened everything up to spec,put my tools away, had a rest due to sudden chest pains,  >:(........then went for a test drive on local bumpy backroads.
Result is that its now all perfect, and the front end is nice and stiff / solid, due to the plod spec springs & dampers.  :) :) :)
Well worth checking, even if it nearly did give me a heart attack.  ;D ;D

Just need to fork out to have the wheel alignment done - again - to finish the job off. Will be aligned to WIM spec this time, so I'm looking forward to seeing how it drives after that.  :)
Title: Re: Knocking n/s/f
Post by: Migv6 le Frog Fan on 19 April 2017, 16:16:25
Actually, I have one more question. If changing the rear doughnut bushes does that affect the rear wheel alignment ?
The reason I ask is, that I have a new pair to fit at some point over the summer. If it affects alignment, I will try and get them changed sooner rather than later, so I can get the alignment done asap.
Tia.  :)
Title: Re: Knocking n/s/f
Post by: Doctor Gollum on 19 April 2017, 18:48:56
Shouldn't make any difference, but if in doubt... ;)
Title: Re: Knocking n/s/f
Post by: cam.in.head on 19 April 2017, 19:57:55
As above .shouldnt make any difference providing the bushes were centred before and no one has tried to alter toe / thrust angle if 1 mounting was out/damaged/replaced singularly.both sides can be perfect in terms of thrust angle but still too far rear wards thou due to the large clearance in the captive nut and centre bolt/ bush bore.this does in my opinion put extra strain on the rear diff mounts. Or at least it did on my car.no one else has ever to my knowledge had issues .