Wobbly under braking

[mymini007]

Drove the patrol home from work tonight, and under braking it feels like the discs are warped, is this likely to be the case or could it be something else, warn steering components? Or just the big chunky tyres?

 

[makeitfit]

King pin bearings 10-1 :thumb2

 

[mymini007]

King pin bearings 10-1 :thumb2

Big job? :nenau

 

[mymini007]

http://www.ebay.co.uk/itm/Front-Axl...=AU_Car_Parts_Accessories&hash=item4175de186a

These ?

Is there a definitive way to tell ?

 

[makeitfit]

http://www.ebay.co.uk/itm/Front-Axl...=AU_Car_Parts_Accessories&hash=item4175de186a

These ?

Is there a definitive way to tell ?

You can get the bearings from Milners and get club discount too :thumbs
Chances are though you can take out a shim and it may be enough.
Not a big job as long as you're careful taking out the bolts. Clean the area first. I think the way to do it properly is with a fish weighing scale or similar. You need a certain load on the swivel hub to know the bearings are correctly shimmed
I took one out at a time :lol
Definitive answer : RTFM :sly

 

[cncfabs]

Justdone my fourtrak very easy job.check same as wheel bearing you can see the play in swivel.I tried removing shims doesnt work if bearings are shot.I replaced the bearings and installed original shims.got my bearings from milners

 

[mymini007]

If this was the case and it is the bearings, would I not be able to feel this through the steering wheel rather than the brake pedal.

I spoke to the previous owner again and he said it only started when the bigger tyres were fitted, could this have been an underlying issue that has been exaggerated by the heavier tyres?

......Alllso, the wobble slows as the truck slows which is what made me think it was discs or a rotational issue, would this be the case if it was the bearings?

Sorry for all the questions but its better to get answers from the people who know rather than trying to RTFM

 

[cncfabs]

If this was the case and it is the bearings, would I not be able to feel this through the steering wheel rather than the brake pedal.

I spoke to the previous owner again and he said it only started when the bigger tyres were fitted, could this have been an underlying issue that has been exaggerated by the heavier tyres?

......Alllso, the wobble slows as the truck slows which is what made me think it was discs or a rotational issue, would this be the case if it was the bearings?

Sorry for all the questions but its better to get answers from the people who know rather than trying to RTFM

Best jack it up give it a good shake see where the play is if any

 

[makeitfit]

It's possible I guess. Do you have any other anomalies with steering for example? Bigger tyres will expose any weaknesses pretty quick that's for sure.
From my experience the rotors are bloody thick and I would have thought they wouldn't warp, but maybe ?

 

[mymini007]

It's possible I guess. Do you have any other anomalies with steering for example? Bigger tyres will expose any weaknesses pretty quick that's for sure.
From my experience the rotors are bloody thick and I would have thought they wouldn't warp, but maybe ?

No, all the other steering attributes seem to be ok, the only issue is under braking. if I brake for 60 kph its like wob wob wob as i slow it becomes wob.....wob.......wob........wob.............wob.....................wob

 

[makeitfit]

Well I still reckon a quick 10 mins under the front will find the issue.
Kack it up and have a wobble n a shake
It only takes a few mins to undo the swivel bearing , oik out a shim and refit. AND it's free. :sly
Try that and go for a spin again.
If it's not that then maybe a quick nip on the wheel bearings.
If it's not that then I guess it could be the actual rotors, in which case whip them off for a quick skim. (assuming their not worn too far)
Good luck

 

[mymini007]

Well I still reckon a quick 10 mins under the front will find the issue.
Kack it up and have a wobble n a shake
It only takes a few mins to undo the swivel bearing , oik out a shim and refit. AND it's free. :sly
Try that and go for a spin again.
If it's not that then maybe a quick nip on the wheel bearings.
If it's not that then I guess it could be the actual rotors, in which case whip them off for a quick skim. (assuming their not worn too far)
Good luck

Its coming home for a service on saturday so I will have a look then

 

[macabethiel]

wobble when braking.

If its warped discs the pedal will kick back creating a judder. Usually this is most obvious between 20-50 mph. Having bigger wheels means it will magnify any wear in the systems that hold the wheel in position.i.e. wheel bearings, arb links, steering arms etc. Other obvious one is wheel balance. Most suspension is designed to cope with the manufacturers specification of wheels & tyres. When you tinker with that you can expect problems. That's why insurers do not want to insure modified vehicles. Also this highlights the differing tyre build quality.

 

[macabethiel]

P.S.

If the wobble is big enough it will not be felt just in the brake pedal it will transmit through the steering column and be felt at the wheel. Its quite novel on Mercs with fly by wire braking such as the new SL warped discs manifest themselves in the steering column and stering wheel due to lack of mechanical connection between brake caliper and brake pedal.

 

[mymini007]

If its warped discs the pedal will kick back creating a judder. Usually this is most obvious between 20-50 mph.

This is what is happening :thumb2