big bumpyness when under full lock
 

Hello

I have just driven my car for the first time in ages (thought i'd better start it ready for the MOT tomorrow) and when pulling off the drive under full lock I felt a very pronounced bumping from the front suspension, I then drove to the petrol station and fuel up where a friend had a look at it for me. It seems that when driving forward under full lock about every one turn off the wheel (16" Fuch) the whole wheel on both sides seems to jolt forward (or so he says), now the car is booked for it's MOT tomorrow so I will take a slow drive there and ask them to look but would like to have a heads up if anyone here can help?
If it helps to know I have lowered the front and rear suspension and fitted the bump steer kit to the steering rack all of which was done last year and the car endured a faultless trip to Le Mans and back earlier in the year.

Thanks in advance

Paul

My SCs does it too. As does every other pre 964 I've driven. Has to be at full or nearly full lock. More pronounced with 225-16s on front.

That's interesting as I have had a set of 17's on there for ages with no problem and I def remember feeling lumpyness when I had the 16" fuch on there before but possibly not this bad, it's only since june the Fuch's have been back on, I hope it is just down to the tyres, I guess we will find out tomorrow??


Cheers

Paul

Got it on mine too. Not sure what it is but I'm guessing that it has to do with suspension settings. I've noticed similar action on race cars moving around the garage area.

It is normal, it's just tire scrub. The tires are not following a parallel radius at near full lock and scrub or work against each other. As others have noted it is more pronounced with 225 street tires or track tires.

the ackerman is off at full lock. not much you can do about it. a non-problem really.

thanks for giving it a name....

Ackerman

I learn something new every day.

My 88 Carrera experiences the same bump way before full lock going forward and backwards. It has become more noticeable in recent months and I am concerned that something may be loose in the steering rack mechanism.
If this were a normal condition, it would happen in other vehicles, wouldn't it? My other car does not do it at all.
The front tires on my Carrera are 205-50-16s.
Does anyone know what else to check?
R.G.

I experienced this when I first got my car mostly in reverse. Checked everything 3 times and replaced wheel bearings. helped a little but still there. Finally came across the steering geometry answer several years ago, I explained this to my friends as "it's a racing thing" Now, I have a name for it. Thanks John!!