O/S front wheel juddering under load

[Oxyuris]

So, went to Rockingham yesterday and, despite being the slowest and scruffiest car out there, we had a great time, however during the morning we started to get a juddering from the front o/s wheel around pif-paf and gracelands and occasionally turn one, which really affected confidence. It didn't get any worse and could only be felt on the left handers, which wasn't great for a counter-clockwise circuit.

Nothing is loose in the suspension, the driveshaft appears fine and the wheel bearing is smooth with no movement. I have read that in some circumstances the engine can move to the offside and put pressure on the o/s driveshaft causing juddering. Is this likely to be the cause and does anyone have any experience of this?

I'd like to get it sorted before our next trackday but I'm not sure where I am going to be able to replicate those kind of loads on public road, I guess a 'belt and braces' approach of replacing as much as possible on that corner as well as improving engine mounts is the way forward but could incur some unnecessary expense. So the input of anyone that has had similar problems and fixed them would be really appreciated.

Oh and it's a standard, unmodified (apart from exhaust and airbox) '02 172.

 

[White16valver]

Are your wheelnuts tight? lol

Was it only under acceleration that it happened?

Have you tried swapping tyres from side to side to see if the juddering moves?

 

[Oxyuris]

Definitely not wheelnuts.
It only happened when the wheel was fully loaded through a left hand corner, I wasn't about to fully lift off to see if the noise stopped but reasonable throttle adjustments made no difference to the noise.

I didn't swap wheels around, but that is because I really don't believe it's a tyre or wheel problem due to the way it feels.

 

[bloke]

Did you try the bearing with the cv out or still in?

 

[Oxyuris]

Still in, not had time to dismantle yet and would rather get any necessary new bits before doing so, although I understand this might not be possible.

 

[JamesBryan]

I'd still go with the wheel bearing theory tbh.

Just because it feels smooth by hand doesn't mean it seems ok, you won't be generating the forces it goes through by hand.

 

[STEVE.M]

I have read that in some circumstances the engine can move to the offside and put pressure on the o/s driveshaft causing juddering. Is this likely to be the cause and does anyone have any experience of this?

Oh and it's a standard, unmodified (apart from exhaust and airbox) '02 172.

Yes, I have experienced this.

I have camber adjustable coilovers, and when running with negative camber, the RH driveshaft would bind when lent on hard in lefthanders.

As proof, adjusting out the negative camber stopped this, as it moved the wheel bearing away from the engine/gearbox assembly.

Your cheapest option is to see if you can move the engine over to the left, as the top RH head mount is slotted, and install one of Powerflex`s inserts.

Photo courtesy of Kam racing.

 

[Oxyuris]

@JamesBryan I appreciate what you are saying but it doesn't feel or act like any wheel bearing failure I've had before, if it was the bearing making that vibration I would expect to be picking up bits of metal or probably the wheel and hub as it bounces off down the track

@STEVE.M, thank you.
So just to confirm it only happened under heavy load on left hand bends and is a rhythmic juddering that you can feel through the steering and initially feels like something is very wrong with the tyre but isn't?

Is moving the engine and adding the powerflex insert how you solved it and would it be worth replacing the standard mount at the same time?

 

[STEVE.M]

@JamesBryan I appreciate what you are saying but it doesn't feel or act like any wheel bearing failure I've had before, if it was the bearing making that vibration I would expect to be picking up bits of metal or probably the wheel and hub as it bounces off down the track

@STEVE.M, thank you.
So just to confirm it only happened under heavy load on left hand bends and is a rhythmic juddering that you can feel through the steering and initially feels like something is very wrong with the tyre but isn't?

Is moving the engine and adding the powerflex insert how you solved it and would it be worth replacing the standard mount at the same time?

Yes & no, in that order.

Occurrence was just before the inside rear becomes airborne on left handers in my case, though I have read of at least one person experiencing the same

problem with the LH shaft on Paddock at Brands.

The standard mount was recent anyway, but if you are considering replacing the original mount & using the insert, you might as well replace it with a

Vibratec/K-Tec mount for very similar money.

The shaft on mine at the time was a low mileage (15k) genuine exchange unit, before someone throws after market shafts into the speculation, and the wheel

bearing had only covered 3k miles, and is still holding up 33k later.

 

[White16valver]

If it's a rhythmic 'throbbing' (snigger) through the shell under load, it could be a sticky CV joint gripping-releasing-gripping-releasing-etc., but only doing it when under load?

 

[Brigsy]

I would be looking at the wheel bearing and cv joint if the car is running stock suspension. I have had similar wheel bearing issues on other cars.