Knocking and bad cornering

[James k]

Hi,
For about the past week I've had a knocking from my front nearside suspension. It knocks when I go over a bump and knocks rhythmically when turning a sharp corner. The car is also 'jumping' round sharp corners. i.e. The wheels lose contact with the ground and it hops. I've jacked it up and tried to see if the trunnion is loose which it doesn't seem to be. I have noticed that the car is very easy to bounce up and down on that side so it could be shock absorber related. Would that cause these symptoms? I haven't had a chance to do a proper inspection yet but do you have any suggestions as to what I should be checking/ looking out for?

Thanks,
James

[simmitc]

Check that the damper is secure to the body (4 bolts should be tight and secured by lock tabs). Check that the damper arm moves only up and down with no other play. Check that the eye bolt is secure in the chassis leg. Check the tie rod, it's mountings, and bushes. Check the wheel bearing. Do not drive the car until you have ascertained where the problem lies.

Do you get the knocking sound when bouncing the car up and down?

[simmitc]

Another thought, also check the torsion bar mounting where it attaches to the cross member.

[bmcecosse]

Also look at the front mount of the tie-bar, running forward to the front edge of the chassis leg. It's difficult to assess the kingpin / trunion condition with load on the suspension - I would unload the torsion bar and take it apart for inspection - before it collapses in an embarrassing heap in the middle of a busy roundabout...... And if all that looks ok - drain and refill the dampers with SAE 40 oil !

[The vast minority]

Do the static checks on things mentioned first and then get it supported on the chassis legs with wheels still on but clear of the ground. You want wheels on to make it easier to find the problem.

Now grasp each wheel in turn and give it a jolly good workout. In out, side to side, top to bottom, give it a good spin. The problem should be obvious with such actions. If required get an assistant to help whilst you watch. Obviously be careful, especially with someone pummelling the suspension if you are under there. I always put old wheels and tyres under a car that I'm going to get underneath.

As you have rebuilt an engine, I'm thinking you will be able to identify the problem from the above method.

Al

[MrIan]

Do the static checks on things mentioned first and then get it supported on the chassis legs with wheels still on but clear of the ground. You want wheels on to make it easier to find the problem.

Now grasp each wheel in turn and give it a jolly good workout. In out, side to side, top to bottom, give it a good spin. The problem should be obvious with such actions. If required get an assistant to help whilst you watch. Obviously be careful, especially with someone pummelling the suspension if you are under there. I always put old wheels and tyres under a car that I'm going to get underneath.

As you have rebuilt an engine, I'm thinking you will be able to identify the problem from the above method.

Al

To check the front suspension joints you need to have the car on stands AND jack up the lower arm to relieve the torsion bar pressure or else movement can not be detected as it's held tight. This is the reason worn trunnions are missed because people don't 'double jack' to check mogs front suspension.

[bmcecosse]

Or as I suggested earlier - take it apart and inspect the king pin - if the threads are 'sharp' and the trunions are moving about on the threads - it's scrap. Don't even consider just fitting new trunions.......

[67-2door]

I've got an occasional loud knock from the nearside front of my car too. Haven't spotted anything wrong yet & the mot man didn't pick anything up. I'll be interested to know what yours turns out to be.

[simmitc]

Knocks can also be caused by missing bump stops and rebound rubbers, but they would not normally cause poor cornering. Still worth checking...

[James k]

I'm away at the moment but I'll check all of those points when I get back. Thanks for all the pointers!

[Trickydicky]

Also disconnect the track rod end and check for play in the steering rack. That could be the source of the rattle and knocking.

[simmitc]

And indeed, check that the rack is securely mounted. I have seen one fractured clamp, but that really is highly unusual.