Front Suspension Issues - what do you think.

[101RRS]

Well my RRS has now done 160,000km - within the last 15,000km I have replaced the front disks (PBR) and pads, put on new Nitto Terra Grappler ATs and had a full wheel alignment. The front end is all original and for a little while the suspension arms have been making a bit of noise but not too bad mainly on poor town streets rather highways or offroad.

When I got the new tyres, the balance was not the greatest but the Nittos have lots of casting dags on them so I decided to leave the balance as was and see what happens.

For the last two months I have been doing lots of kms and not have had the time to have the car off the road for maintenance other than changing the engine oil and filter.

Over the past few weeks the balance seems to have got worse at around 90kph but fine at other speeds then when braking from highway speeds there was a noticeable shake from the front end and the steering wheel until speed slowed a bit and then ok - a bit like the front end death wobbles at speed in a Series 1 with dodgy swivel pins - but no where near as bad. Around town braking, steering and the front end all perform perfectly.

On Thursday I had to go to the coast and the car was fine until I was going down Macquarie Pass where the wobbles got really bad when braking for the bends - in fact a loud knock from the front end was audible matching the shaking of the wheel. At the bottom of the pass - all gone and on the straight and level no issues even with test braking from 100kph.

To start the diagnotic process I got a front wheel balance yesterday and that improved things a little but the wheel shake is still there sometimes.

So to diagnose

Is it - wheel balance, warped disks, the worn suspension bushes (upper and or lower), worn upper/lower king pins, steering tie rods or a combination of the lot.

WHAT DO YOU THINK?

This is what I think.

I know the lower suspension bushes are worn and the balance on the front wheels was not good. The brake disks are new so unlikely to be warped. The problem only shows up when braking at higher speed or under heavy load and is like the series 1 death wobble - so I think my suspension rubbers are worn (known) and when braking the wheel balance issue is causing the whole lot to be loaded up and magnifies the movement in the front suspension system, in particular the upper and lower kingpins causing the audible knock. I dont think I have a brake warp issue as the issue is not consistent across the speed range.

So - wheels are now balanced, brakes are probably fine - do I just order new Dephi lower suspension arms with a new king pin from Advanced Factors and get a new top kingpins as well. Are steering arm ends also likely need to replaced.

The car drives fine with no noticeable issues at all around town - in fact the rear roll bar rubbers back more noise than the front lower suspension arms.

SO WHAT DO YOU THINK?

Thanks

Garry

[Ean Austral]

Well my RRS has now done 160,000km - within the last 15,000km I have replaced the front disks (PBR) and pads, put on new Nitto Terra Grappler ATs and had a full wheel alignment. The front end is all original and for a little while the suspension arms have been making a bit of noise but not too bad mainly on poor town streets rather highways or offroad.

When I got the new tyres, the balance was not the greatest but the Nittos have lots of casting dags on them so I decided to leave the balance as was and see what happens.

For the last two months I have been doing lots of kms and not have had the time to have the car off the road for maintenance other than changing the engine oil and filter.

Over the past few weeks the balance seems to have got worse at around 90kph but fine at other speeds then when braking from highway speeds there was a noticeable shake from the front end and the steering wheel until speed slowed a bit and then ok - a bit like the front end death wobbles at speed in a Series 1 with dodgy swivel pins - but no where near as bad. Around town braking, steering and the front end all perform perfectly.

On Thursday I had to go to the coast and the car was fine until I was going down Macquarie Pass where the wobbles got really bad when braking for the bends - in fact a loud knock from the front end was audible matching the shaking of the wheel. At the bottom of the pass - all gone and on the straight and level no issues even with test braking from 100kph.

To start the diagnotic process I got a front wheel balance yesterday and that improved things a little but the wheel shake is still there sometimes.

So to diagnose

Is it - wheel balance, warped disks, the worn suspension bushes (upper and or lower), worn upper/lower king pins, steering tie rods or a combination of the lot.

WHAT DO YOU THINK?

This is what I think.

I know the lower suspension bushes are worn and the balance on the front wheels was not good. The brake disks are new so unlikely to be warped. The problem only shows up when braking at higher speed or under heavy load and is like the series 1 death wobble - so I think my suspension rubbers are worn (known) and when braking the wheel balance issue is causing the whole lot to be loaded up and magnifies the movement in the front suspension system, in particular the upper and lower kingpins causing the audible knock. I dont think I have a brake warp issue as the issue is not consistent across the speed range.

So - wheels are now balanced, brakes are probably fine - do I just order new Dephi lower suspension arms with a new king pin from Advanced Factors and get a new top kingpins as well. Are steering arm ends also likely need to replaced.

The car drives fine with no noticeable issues at all around town - in fact the rear roll bar rubbers back more noise than the front lower suspension arms.

SO WHAT DO YOU THINK?

Thanks

Garry

This is where i would start . Had issue's similar at last front pad change .

Cheers Ean

[loanrangie]

With worn bushes you cant align suspension correctly.

[BigJon]

If it has done 160 000km on the original front lower arms, they are knackered. Get new ones and it will transform the way it drives.

[101RRS]

Yes I agree but I am wondering about all the other related components such as upper arms and kingpin and steering tie rods.

At the moment I cant be bothered putting in the lower arms myself so I might get the indy who will do the work to provide an advisory on all the rest.

Thanks

Confirms my thoughts

[Towcar]

I'm in a similar boat.
I didn't get this when braking, I use to get it when the car is cold, like I just jumped on the freeway. and on some road surfaces at 90kmh. Lower control arms being replaced helped 70 percent. Then new brakes helped a little, plus a balance and alignments , I thought about power steering flush...I really want to do king pins, and arms as well as I think that is all contributing.

Would Rimmer Bros be able to supply complete arms with bushes, or where would you get them from?

These cars are a little hard to get right I find, if you want it perfect.
Cheers
Jeremy

[Piddler]

Yep, definitely check King Pins when do arms, would say they are probably worn.
I think Arms and King Pins will transform.
Cheers

[simmo1]

wonder if it might be wise to think outside the square. Years back I had similar issues with an 80 series cruiser. I had fitted new Dunlop adventure tyres. These were a tough tyre and I reckon not made to very high standards. After about 2000km I had them swapped to BFF muddies, problem gone completely. Then about a further 70,000km this issued emerged again. Replaced the tyres as they were well worn. It turns out 2 tyres at diagonal corners had started to delaminates. But the symptoms in both cases were very similar to what you are describing.
So it might be worth a try to simply shift the tyres about on the car, a front to rear rotation. This would at least show whether the tyres are contributors or not.
Cheers Alan

[BigJon]

What are the king pins that people are referring to? Cars haven't had king pins since the 1960s!

[Geedublya]

I think they mean the ball joints but I was confused as well.

[Fatso]

Have done 170Km in my 2007 RRS and the Arms are not fubbard , but did have a slight wobble under heavy braking after fitting new disks and pads but went away after a shortwhile , and no probs since ..