Front vibration under vibration - what should I be looking at?

[Edzhere]

My car has always had a bit of a vibration in the front but even though I replaced the front discs, pads and tie rod ends, it's getting worse.

I assume something is worn in the suspension bushes. I noticed comments on here that MM only sell the whole control arm for $1k but you can buy bushes on ebay for $100.

[oldn64]

Gone are the days where workshops actually fix stuff, with time schedules and curn them over mentality they are looking for quick solutions whihc dont take time. So to replace a arm is far quicker then pressing and assembling a bush into the existing arm. Repco and bursons etc (national parts too) have gne this route for older car, no longer do you get a control arm bush anymore you get a complete arm with you needing to hand yours back over as a exchange. (the early commodores are particularly a good example for lower rear control arms.)

Years ago and I still have a set for the race car I would press these in myself. The bush was only $25 and 30minutes of my time, the arm now is $175 eek, but then again how many actually fitted the bush correctly too. Rare spares pulled complete door skins from some of their line up simply because people who didnt do panel fabrication had not idea how to make the skin fit properly and blamed the replacement skin not their workmanship.

So if you are confident, have access to tools or can make a tool to do it (no a vice will not work generally you will break you vice.) then I say go for it. It doesnt take much to do the job right if you pay attention to detail, However, if you will not be able to complete the job and tooling is a problem then you might find this difficult to complete and then call on someone else who will have to do the job for you and thus the arm would have been a cheaper easier option. Check out peddars and see what they would charge for an arm, surely they would be cheaper then a dealer/factor part.

Oh and stay away from nolathane.

[spot01]

Simple questions first:

How many kms on the car?

I assume the vibration is the same with different tyres & after balancing?

Also, as I notice you have off road tyres, have you checked for mud, etc. stuck inside the rims or even inside the hub & disc vents? (I note you have replaced the discs, but as it is getting worse, worth checking).

The new discs could have warped - does it vary when braking or not? Do you drive through water crossings with hot discs?

[old Jack]

"Front vibration under vibration" and the subsequent details in the OP's post is not enough info to be able to assist in a more accurate way.
It could be a tyre/wheel balance problem.
It could be incorrect wheel torque.
It could be a tyre wear or delamination of a tyre.
It could be engine mounts or gear box mounts.
It could be driveshaft joints.
It could be wheel bearings.

We need more detail to under what conditions the vibrations are felt, like;
engine rpm, speed, gear being used, tyre size, wheel offset, suspension ride height, manual or auto trans?

OJ.

[Edzhere]

"Front vibration under vibration" and the subsequent details in the OP's post is not enough info to be able to assist in a more accurate way.
It could be a tyre/wheel balance problem.
It could be incorrect wheel torque.
It could be a tyre wear or delamination of a tyre.
It could be engine mounts or gear box mounts.
It could be driveshaft joints.
It could be wheel bearings.

We need more detail to under what conditions the vibrations are felt, like;
engine rpm, speed, gear being used, tyre size, wheel offset, suspension ride height, manual or auto trans?

OJ.

Thanks all for the feedback, I should have given more info.

Car has 260,000 km on it. have all the service records but they don't show any suspension/bushes/parts replaced. Just normal logbook type servicing at a general workshop, but the same one for all it's life before I bought it 2.5 years ago.

Vibration only occurs under brakes as I'm slowing to come into a roundabout or intersection, smooth as silk at all other times. Initially I thought it might be just due to corrugations in the road from trucks slowing down it happens everywhere now which makes me suspect wear in the front. If I brake really gently it does not occur, firm braking and it shudders. You can feel it through the car rather than the steering wheel or pedal, my young son even commented a couple of times, sitting in the front passenger seat.

Didn't change after fitting new discs and pads, very careful to clean the hub before fitting discs, clean and grease calliper sliders, torque wheels etc. Wheels have been rebalanced recently and a 4 wheel alignment done.

I'll probably book it into Pedders next week for one of their complete suspension and brake checks for $26, but I'm a bit wary of them because when I booked my Range Rover in many years ago they told me I needed just about all of the suspension bushes replaced. When I booked it in with my mechanic I usually use he said he could only find one pair of bushes he recommended replacing. I think the $26 check is just a good way of getting unsuspecting customers in the door sometimes.

I do have access to a high power press and have done this on older cars but from past experience I know you need the correct size mandrel to push the old ones out and new ones in. It's another school so I'd have to measure the bushes first to check and then find the time to do it.

[old Jack]

Does the shudder frequency change as the vehicle speed changes?
Does the shudder only happen between a certain speed range?
Have the brakes been bled according to the service manual?
Does the shudder get better or worse or the same when in 4H compared to 2H?
Does the shudder happen when you have your 2nd set of tyres fitted?
Does the shudder occur when firm braking and the steering wheel is pointed straight ahead or only if there is also some steering input or both?
Are there any lights flashing on the dash when the shudder happens?
Do all 4 tyres have equal tread depth?
Is the tread wear even or is there unusually wear on the tyres, can you post a photo of looking across the tyre tread face both both left and right tyres.
What are your front ride heights, measure from the centre of the wheel hub to the underside of the wheel arch in a vertical line, when the car is parked on level ground.

OJ.

[oldn64]

So is it only under braking or as the car drops speed? (ie coasting)

Can you get it to happen up a hill without assistance of the brakes?
does it change with the pressure you apply to the brakes?
is it pulling in any one direction?
Have you torqued or retorqued your wheel nuts lately?
if you grab the top of the wheel (tyres) and shake it is there a rattle or looseness?
are all the boots in good condition for tierod ends balljoints steering etc.

I think a closer look of many things is need here. Start trying to rule some out.

I would check your upper suspension rubbers too, they maybe floating the shock.

[Edzhere]

I just took it for a number of tests as it's 10 pm and the roads are quiet. If I brake lightly or mediumly from 80, 60 or 40 kmh, the shudder is bad. If I slam the brakes on, there is a slight initial shudder, then no more, just brakes quickly and smoothly. I suspect under heavy braking the suspension components are under full rearward compression so any gaps are taken up reducing front and back flex, therefore vibration. I'd say it's just wear in the suspension.

Do all 4 tyres have equal tread depth? - similar. Tread depth from inside to outside - Pass front 3. Driver Front 6 5 4, Pass back 4, Driver back 4 4 3. I know the tyres are old and this probably doesn't help. It will be interesting when I put my new AT's on if the problem goes away.

Does the shudder frequency change as the vehicle speed changes? - constant as I slow down under light to medium brakes.

Does the shudder only happen between a certain speed range? - Only when slowing under light to medium brakes from any speed

Have the brakes been bled according to the service manual? - only had pads and front discs changed recently, no record of brake fluid being change (probably overdue for a flush!)

Does the shudder get better or worse or the same when in 4H compared to 2H? No difference

Does the shudder happen when you have your 2nd set of tyres fitted? - I'll check on the weekend, will take me a little while to swap 4 wheels over.

Does the shudder occur when firm braking and the steering wheel is pointed straight ahead or only if there is also some steering input or both? - No difference.

Are there any lights flashing on the dash when the shudder happens? - no lights flashing.

Is the tread wear even or is there unusually wear on the tyres, can you post a photo of looking across the tyre tread face both both left and right tyres.
Tread wear is fairly even, the tyres were second hand when I got them.

What are your front ride heights, measure from the centre of the wheel hub to the underside of the wheel arch in a vertical line, when the car is parked on level ground.
Front Pass 490, Front Driver 485, Rear Pass 520, rear Driver 515

I shook the tops of the rims but there is no in or out movement or noises front and rear.

So is it only under braking or as the car drops speed? (ie coasting) - only under braking.

Can you get it to happen up a hill without assistance of the brakes? - no, dead smooth

Does it change with the pressure you apply to the brakes? yes - light to medium shudders, heavy not.

Is it pulling in any one direction? - no brakes nice and straight. Had a 4 wheel alignment done not too long ago.

Have you torqued or retorqued your wheel nuts lately? - no, will do this weekend and then I'll swap wheels and try them.

if you grab the top of the wheel (tyres) and shake it is there a rattle or looseness? - nothing, all good

Are all the boots in good condition for tierod ends (new 5000 km ago),
balljoints steering etc (will check the rest this weekend when wheels are off)

I would check your upper suspension rubbers too, they maybe floating the shock. - yes, thought of that, I'll know more when I pull the wheels off

As I said, it's been getting progressively worse over the last 12 months so I'm pretty sure that it's something in the suspension. I'll have a look when I have it jacked up to swap tyres this weekend and report what I find.

[old Jack]

Is it just a coincidence that the vibration seems to be originating from the front passenger side and the front passenger tyre has a unusual wear pattern?
I would be fitting the spare tyre to the front passenger side and see if there is any change.
Whilst the LHF wheel is off have a close look at the front strut, is it leaking oil?
The vibration could be the front LH wheel bouncing under braking if the strut damping control has deteriorated.
Does the front suspension seem to dive down when braking and particularly turning right?
Does the front of the car bounce up and down after you manual compress the front suspension?
Is the suspension original ? Have any suspension parts been replaced, what and when?

OJ.

[oldn64]

no brakes nice and straight. Had a 4 wheel alignment done not too long ago.

Right, one this I want to point out is having a wheel alignment on worn components can cause interesting results. I am not saying it is the cause but could have contributed to an increase in vibration. IT IS NOT THE CAUSE, so you will still need to find the root cause. I would not put new AT tyres on until this has been resolved you might just happen to get another wheel alignment only to have it chew you new tyres or shudder more.

Definitely have a good look at the suspension and steering components. Did the brake pedal "pulse" or shudder with the vehicle. if so look at the pads and rotors as well.

The only reason I mentioned torquing wheel nuts is that most tyre stores will use a rattle gun to do them up and walk away. I actually request they use a wheel brace and torque wrench on mine. I have seen too many wheels leave vehicles over time from either not being tight enough or being too tight and stretching the threads. Rememebr threads are stress concentrators and thus will fail if too tight. Falcons do it often.

I remember asking a tyre place to use a wheel brace to undo and do up my wheels on my VH Commodore. The note was on the paper and was read by the tyre fitter, who then got angry and used a rattle gun anyway. On complaining to the manager, who then had a word with the fitter, he then in front of the manager tried to remove another wheel with the rattle gun to prove that there is no issue (VH commodores did not have large studs so it was easy to break the 12mm thread) He forgot that he had just put two tyres on the car next to mine and proceeded to break two studs off (in do up mode). long story short the tyre fitter didnt touch my car after that, i got two new studs for free, access to their workshop and the two tyres I wanted for free too. GRRRR. anyway I digress. Check your studs carefully.

when you do have your wheels of make sure the ball joints and the steering tierod ends are tight too. I chased an issue with a brother in laws car for a month where he stated that there was a clunck and the car would shake sometimes into a left hand corner. After some time I found out he had replaced the right hand ball joint (or rather got a mechanic to replace it) and they had not seated it properly into the strut, so while it was tight the taper that the shaft has was not seated into the strut correctly allowing it to rock side to side (we are talkin 1/2 mm here) the only reason I picked it was that the shaft had rust makes on it which was abnormal.

Keep your eye peeled and have a good look around. If you are not able to pick it. go to a peddars outlet and get a 28 point safety check this should highlight what the issue might be. if shock related the shock test will tell you.dont get them to do any work, but more use it as a report card that can then been reviewed and targeted. Often they pick steering rack/box just because.

[old Jack]

Is it just a coincidence that the vibration seems to be originating from the front passenger side and the front passenger tyre has a unusual wear pattern?
I would be fitting the spare tyre to the front passenger side and see if there is any change.
Whilst the LHF wheel is off have a close look at the front strut, is it leaking oil?
The vibration could be the front LH wheel bouncing under braking if the strut damping control has deteriorated.
Does the front suspension seem to dive down when braking and particularly turning right?
Does the front of the car bounce up and down after you manual compress the front suspension?
Is the suspension original ? Have any suspension parts been replaced, what and when?

OJ.

Further to the above post, I would be also checking the lower strut bush for wear, the top strut rubbers for wear and the top mount for cracking.
Apart from complete removal and disassembly of the strut, you can get a good idea by removing the wheel, making sure the chassis/subframe is supported on an axle stand and then slowly jack up from the lower control arm from where it attaches to the hub knuckle. Watch to see if they is any movement in the lower strut bush and the top mount, before the coil stars to compress under the weight of the vehicle.

OJ.

[Edzhere]

Does the front of the car bounce up and down after you manual compress the front suspension? - You're kidding right? I actually went out and tried this and I weigh 115 kg and I couldn't get either side to move down 10 mm let alone bounce. This may work with a light car but not with a heavy 4wd.
Is the suspension original ? Have any suspension parts been replaced, what and when? Had the car nearly 3 years. Have the full service history from the previous owner but no details on it of any suspension repairs. Doesn't mean it wasn't worked on elsewhere, but have no records. I bought the car from a dealer in WA and managed to track down all the service records at his regular mechanic. Car is stock height.

All great advice above, a thousand things to check. I'll have to wait until next weekend as I need to get my toy ready for a car show this weekend. It's been off the road for 11 months.

I fitted a new motor, gearbox and new dash and want to take it to a car show Sunday for it's first outing if I can get the last bit of the wiring done.

I'll book the Pajero in to Pedders next week for a start as their check still only costs $26 and they are pretty thorough and have a hoist, however any work that is needed I can do myself. They are only 10 minutes walk from work. Then next weekend I'll pull wheels of and check all the front suspension as suggested. You've given me some good tips to give it a thorough going over. I'll report back in 2 weeks.

[Edzhere]

Is it just a coincidence that the vibration seems to be originating from the front passenger side and the front passenger tyre has a unusual wear pattern?
I would be fitting the spare tyre to the front passenger side and see if there is any change.
Whilst the LHF wheel is off have a close look at the front strut, is it leaking oil?
The vibration could be the front LH wheel bouncing under braking if the strut damping control has deteriorated.

OJ.

Vibration is from the front, not just the left.

[oldn64]

enjoy the car show Edzhere, you will find the issue it is just a case of what the root cause is, once that becomes apparent everything will fall into place.

Pedders check is cheap for what you get and they have the specialised equipment to check shocks and suspension travel etc, if the shock is suspect then it will become apparent. Also if their machine creates a clunk or the vibration where they can see what is going on then the problem i am sure will be identified.

I am of two minds as to whether to tell them about the issue or let the safety check be performed without prior knowledge. Whatever happens make sure that the suspension is tested, I cannot remember whether this was an extra or included in the normal 28 point check but it is cheap diagnostics