12 replies to this topic

[Jacob]

Hello, 

 

I drive a '69 mini fitted with front disk brakes. I have been experiencing some knocking coming from the drivers footwell, which increases and decreases in frequency as the car accelerates and slows down respectively. To ensure that it isn't anything with the engine, I have run the car out of gear down a hill and the same knocking is present. 

 

Also, the left front wheel (drivers side) has some play when in the air. I have replaced and properly shimmed the ball joints and ensured the condition the condition of the track rod end is good. And ensured everything is torqued to the right spec, including the crown nut with the correct spec for disk brakes. 

 

Anyone have any idea as to what it might be?

 

 

[sonikk4]

Could be as simple as the rear mount for the subframe. Make sure the bolt is tight.

[MiddletoM]

does it happen when braking? Sometimes a warped disc can cause a slight knocking sound.

[DeadSquare]

Worn track-rod end ?

[johnv]

See if the steering rack bush is OK.. Grab the arm out out the rack and see if you can make it move

[cal844]

Can be alot of things, I had a similar knock and it was a combination of the engine steady bush bolts were slightly loose so that visually they were tight but upon tight checking they were 2 turns loose, and also look at the steering rack for play across the rack and also the bushes in either end (the long end bush wears faster)

[luismx123]

Had the same issue. Was knocking on my left side, also lhd mini. Turned out being my subframe hitting the body as the rubber bushing was dead in the tower mount. Swapped for solid mounts and it went away. 
I found the sound was heard more when in 4th gear at 1.2-1.5k rpm and pressing the accelerator. LArge vibrations caused the knocking which made sense after we changed the mounts and saw the bushings....but we wouldve never come to that conclusion. Was purely by chance!

[InnoCooperExport]

Had the same issue. Was knocking on my left side, also lhd mini. Turned out being my subframe hitting the body as the rubber bushing was dead in the tower mount. Swapped for solid mounts and it went away.
I found the sound was heard more when in 4th gear at 1.2-1.5k rpm and pressing the accelerator. LArge vibrations caused the knocking which made sense after we changed the mounts and saw the bushings....but we wouldve never come to that conclusion. Was purely by chance!

This is a 69 remember, so should be solid mount already. My guess would be lower engine steady bush.

[Spider]

Universal Joint on the way out ?

[Jacob]

I have checked for these issues and it doesn't seem to be the issue. However, when lifting the car up, I have noticed that the left front wheel (where the knocking seems to come from) when moved left to right and up and down (as you would to check for worn ball joint or worn track rod ends) there is quite a bit of play in the wheel.

 

I have replaced both the ball joints and correctly shimed them, same as the track rod end. But the left front still has quite some play in it. I think this might be the issue. So have checked the calliper and the play seems to come from the calliper-hub assembly, but I cannot locate what part it is. Anyone have any suggestions? 

 

Also, do you think this is what is causing the knocking?

 

Thank you for all your previous help.

[luismx123]

could be the bearings are gone. or possibly the inner area of the hub where the bearing seats fit could be worn. worth checking if you they haven't been swapped in a while.... OR first loosen the castle nut and then retighten to 250nm and see if it goes further.... I've seen this cause play in the bearings before as the whole setup gets compressed

[Jacob]

Thanks everyone. It turns out the sound was coming from the bolts that attach the drive flange to the brake disc. Since they're simple bolts they come loose with the vibration and my wheel was not riding against the drive flange but was rather riding on the lip of the brake disc. This meant that all the pressure was put on those four bolts. 

[richmondclassicsnorthwales]

With a 69 Mini, do you have the inner rubber couplings on the driveshafts ?

 

These can perish being rubber, and in the worst case scenario, can fly apart and disintegrate on a run.

 

Unfortunately, not easy to look at where they are, and not a 5 minute job, but, these failed on me once, and this was the problem.

 

Just some thing to bear in mind if at a later date you come across a similar scenario and get stumped for ideas. I had a very similar experience, so just passing it on.