Car steering vibration at full-lock

Any suggestions what’s causing my steering wheel to vibrate slightly at low-speed full-lock?
Noticed it the other day in a multi-storey car-park and assumed it was slight understeer on the polished concrete floor, but then had it again coming out of the drive.

Options seem to be from Google:
PAS pump and/or fluid level
CV Joint
Tyre-rub

I’ll check for tyre-rub later as I’m switching to my winter wheels today. If it makes any odds, it s a 2.0 TDCi C-Max

CV Joint is most likely

The rubber gaiters that protect them are easily damaged and then the bearings are exposed to road crap and wear out.

After time the grease in the CV joint migrates away from the bearing surfaces, so at full lock there is little or no lubrication, hence the vibration (also there may be some clicking or clonking).
You can extend their life by getting them re-greased, but if the rubber boot has split it will need to be replaced, as its an MOT failure.

Also consider an issue with the power steering fluid by-pass valve.

Pulley on your power steering belt?

My bet will be pump, are you holding it against the lock stops ? (On full lock)

Another vote for power steering pump try it when stationary.

+1 for steering pump. Could be low fluid or on its way out. If it makes a horrible racket on full lock when stationary then it could be your alternator clutch pulley.

PAS pump – I had ongoing issues with this on my 08 Focus. As above, lean the wheel into full lock when stationary (obv this isn’t how you usually drive eh 😀 )

Mine used to whirr / grind / vibrate. Had it ‘fixed’ twice under warranty but this only seemed to be a temporary fix, it eventually came back both times. Glad when i got rid of it!

+1 for pump
if it starts making bad noises

Right, just checked. Full-lock when stationary makes a very quiet whine/hum, nothing like the vibration when moving. I guess the whine is the pump just working, but otherwise no problems.

CV joint then? Sounds expensive…

Try not to hold your steering on full lock (for too long if possible).

Have you thought about leaving it and just carrying on, stiff upper-lip and all that…

Try not to hold your steering on full lock

Have you thought about leaving it and just carrying on,

Reminds me of the classic doctor joke:

Patient: It hurts when I do this
Doctor: Don’t do it then!

Brilliant.

I don’t hold it on full-lock more than necessary obviously, but do need to give it full-lock getting in/out of the the drive as our road is narrow.

I’ll get into the garage for a look next week. Noises like this on a 120,000 mile car soon escalate, as does the cost to fix it…