Vibration on Acceleration

[Wacky]

Hi Everyone,

As you can tell by my profile and low post count, I am a newby to this site. I have just recently purchased a VS S1 Exec Sedan with 168,000km on it. It's in great condition...drives nice, etc ,etc.

However, one thing that is really niggling me is a vibration upon acceleration, through to about 35/40 km/hr.

I can feel the vibration through the steering wheel and gearshifter.

I know I need to get a wheel alignment ASAP as it pulls to the right a bit, however I get the feeling it's something to do with the drive train, as rolling down a hill from 0km/hr does not cause this vibration, nor revving the engine in neutral.

This site has been a great and impressive source of information and initial reseach has led me to want to investigate the Uni Joints (I believe there are two of them between the gear box and the diff (?).

I am getting a workshop manual ASAP (I prefer Gegory's, but is it the best?), but I'm wondering if the symptoms match to Uni Joints, and whether there might be other issues, such as rubber bushes on various linkages (can anyone expand on the bushes info? Such as how many there are, what their proper names are, should I replace them anyway, if so, what do I ask for at the shop?)

Also, in Sydney (North Side) what are the best shops for these sorts of parts? Autobarn, Repco ?

Thanks for reading my long winded post...I hope I made myslef clearer than by writing a short confusing one.

[Wacky]

I also just found this through the VS Faults sticky post:

Tail shaft centre mount - Commodores use a 2 piece tail shaft and the centre is supported by a centre mount bearing which is bolted to the floor. The centre mount bearing is caged in rubber which helps absorb torsional twist and vibrations, but the rubber can split which allows the centre of the tail shaft to rotate unsupported. Tail shaft centre mount bearings are readily available, but the tail shaft needs to be separated for installation, and correct reassembly is important and best left to qualified repairers. The tail shaft centre mount bracket is also responsible for tail shaft drive angle. When a vehicle is lowered, repositioning of the centre mount bracket spacers is required to correct the drive angle, and reduce vibrations during take off.

[Patrio7]

yeah if my vs s1 comes under heavy acceleration [ with passengers or a trailer ] it makes a thudding noise from around the rear transmission area, i figured its a mount or rubber somewhere

[Jamie_87]

my calais has same prob, cant work out why it does it, im thinking trans problem/tailshaft??
ive learnt to live with it,not gonna bother spending any more money trying to fix it, might as well save it for a better car.

[boojak87]

I was told it's normal for a VS to shudder under hard acceleration. . It does get to be a bit of a pain in the ass sometimes though because usually you associate the vibration with stress and it's struggling to keep up. If someone could pinpoint the problem and give a fix it'd be awesome. Thanks!

[hako]

There are 1001 stories about exactly why it happens and just as many cures.

[phatwagon4u]

yeah if my vs s1 comes under heavy acceleration [ with passengers or a trailer ] it makes a thudding noise from around the rear transmission area, i figured its a mount or rubber somewhere

if you have symptoms like this it sounds like the transmission mount has broken,at the rear of the trans there is a rubber mount where it bolts the trans too the chassis,
what happens is the rubber mount seperates from its metal mount (they are glued together),so it creates a thud when the engine is under load.
they only way too check if the mount is ok is too remove the mount and bracket off your trans,if it is fu#ked it will fall into 2 pieces
hope this help

[VRAddiction]

this may be odd and little off but try get your wheels balanced and see how it goes??

try basic stuff first

[94 Stato V8]

Does the vibration cease as soon as you back off? While driving under light acceleration can you 'pedal it' to make the noise come and go? If so, my guess would be uni's and centre bearing. You can check what these are like by grabbing the tailshaft and twisting it back and forth with the car in gear (or Park for auto's) it will move a little, but it will move a fair bit more (or even clunk) if things are amiss. Also try pushing the tailshaft up and down, if the centre bearing is gone, it'll also move a fair bit.

[betts]

yea my VR does the same thing only when theres passengers in the car though, ive also been told that VR's and VS's do this normally under heavy accellaration. ive had my car for yonks and nothing in the transmission has gone wrong so i figure its just a normal thing.

[Infus10n]

If the gearshifter moves around alot and is quite noticeable then check your mounts. But quite naturally the gearshifter will move a bit.

[97 SEN]

I was told it's normal for a VS to shudder under hard acceleration. . It does get to be a bit of a pain in the ass sometimes though because usually you associate the vibration with stress and it's struggling to keep up. If someone could pinpoint the problem and give a fix it'd be awesome. Thanks!

I was told that also. Fixing the broken engine mount fixed the problem straight away though. dodgey cars sales people try to get away with murder some times (this was when the car was still under warrenty and they had to fix it)

[Patrio7]

if you have symptoms like this it sounds like the transmission mount has broken,at the rear of the trans there is a rubber mount where it bolts the trans too the chassis,
what happens is the rubber mount seperates from its metal mount (they are glued together),so it creates a thud when the engine is under load.
they only way too check if the mount is ok is too remove the mount and bracket off your trans,if it is fu#ked it will fall into 2 pieces
hope this help

hmm well my car has been though a lot [ had it on two wheels once ] so i'd say its safe to assume its buggered.

c'mon tax cheque.......

[boojak87]

Haha lucky you say that! That's actually one of the things that the service guys picked up on the last major service (that engine mounts are going out) but this problem has been around since we bought the car at 50,000kms (now at 218,000). How much would I be looking at for new engine mounts? Supplied and fitted?

Thanks, Boojakz

[97 SEN]

I don't know, i didn't have to pay for it. It looks like a pain to do though.

[sircruisealotVS]

i dunno whose been telling you guys such things...but it is definately NOT normal for a vr/vs to shudder under heavy acceleration. in fact they are actually very smooth to respond to heavy throttle.
something is amiss if this is happening to you, and id start checking out your drivetrain and mounts asap.

[hako]

As sircruisealotVS says there may well be something wrong as some Commodores are smooth, however Commodores always have had harsh drivetrains. There's a road test of a VR at:
http://carsguide.news.com.au/story/0...-26236,00.html
which states "There was also a characteristic vibration from the drive line just after takeoff. It went away as you accelerated through the problem zone, but it was a common annoyance with a lot of early Commodores"

[digisol]

Worn engine mounts wil make it vibrate under moderate to hard acceleration, I bet it's fine if you drive off slowly ?

The mount hidden under the A/C compressor is usually the culprit.

[Wacky]

Well, for me, it's acceleration from 0km/hr to about 35/40km/hr...wether that be gentle acceleration or planting my foot...I haven't had a chance to check out the Uni Joints and Centre Bearing yet, but I did get my wheel alignment looked at.

I went to Pedders (read on before bagging me for going to Peders...you can bag me later) to get it done and have their 28 point suspecnsion check as well.

Well, I've got :

** 3 dead bushes on each side at the front, and some sort of plate at the top of the strut is apparently broken on both sides.

** The radius rod on one side is apparently bent slightly (I think he said it's actually straightened as it's normally got a bend)

** Bushes on rear lower arm require replacing (not as urgently)

They did this report for free, and even gave me a quote for fixing it (read in another thread someone else get their report for free too...funny that).

$ 983 !!!!!!

Yup, that's right. Now, I dunno if that's a ripoff or not...but it sounds like it...they also said it needs to be done ASAP within the next 1000km.

Now, I need to get this done, as I'm about to become a father and will be putting my newborn in this car, but

(a) how much would parts be approximately (I saw a thing at auto one in a catalogue for a VS COmmo Nolathane Bush kit for about $350)
(b) How difficult is it to do this stuff at home (assuming you have the right tools)? I have rebuilt engines and gear boxes and done alot of general stuff on cars - like brakes), but never suspension, but I'd love to give it a go.

Any thoughts?

[digisol]

All them bits can be had on Ebay, simple as, I know Ebay sucks but for some stuff it's OK, you may get the radius rod there too.

You'll have to explain just what plate is broken in the top of the struts ?

Radius rod = wreckers NP, new rubbers = Ebay.

Pedders check is $14 here, they will normally be over cuatious with offering advice and spares, if the radius rod is bent you must have hit something, or bought it like that, if so it could have had a front ender.

Rubber bushes last a while, if keeping the car for ever go for the better bushes, personally the cheaper ones do the same thing at 1/4 the price.

[Wacky]

Thanks Digisol !

I think it must be the bearing plates or support plates that are broken...I can't remember exactly...just that he confirmed it was at the top of the strut where it mounts.

Yeah, I'll check Ebay, have no problem with Ebay (always cautious as one should be though).

Re the Radius rod, yeah, it wasn't me (only had the car a few weeks). Pedders guy said someone probably smacked a pothole (there doesn't appear to be any evidence of a front ender.

And yeah, I'll probably have the car for quite a few more years, so I won't go over the top with parts, but won't skimp either.

Thanks, your advice has given me much to think about !

[digisol]

I personally hit a pot hole "AKA small mineshaft" at near 110 and it destroyed the strut, steering rack, inc tie rod end, two wheels, the front wheel had to be changed instantly as it was flat with a 4" dent in the rim, and that hit pretty hard.

To bend the radius rod and have broken upper strut parts check the front end for different paint or overspray, and nuts that have been undone, where normally would never be touched, sounds like it's hit something, does it steer straight ?

My neighbour has a VN ute that had hit something real good, new s/h guards, L + R and new s/h inner guards L + R, new s/h bonnet and hinges, new suspension L + R, new grille, new lights, new apron, damaged / leaking a/c drier first gave it away, all was detailed for resale very well and being the same colours it was hard to see until I spotted the bent L chassis rail, so it had hit something reasonably hard.

Problem is they are made to fold up, you survive, but the car don't.