Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Noisy Mazda thrust bearing?

No but sounds just like it.

Thought this might be worth dropping in the maintenance section. My car developed an annoying faint chirping squeaking noise when idling or driving when the clutch petal was out. Touch the petal slightly and it would stop. Sounded just like a dry knackered old thrust bearing. However it looks to be a known problem and the answer can be found on the MX5 forums.

Vibration from the clutch causes the slave cylinder rod end that mates in the conical socket in the clutch fork to make this noise. The solution is to pull back the cylinder rod by hand and put a blob of thick grease in the socket. I was sceptical but I’ve now done a couple of hundred miles since doing this 30 second job and it’s still quiet. Fingers crossed

Mine does exactly the same, so look forward to trying this, as I had also put it down to the thrust bearing.

Isn't it great when the fix is so simple

Thanks Roger , good to now .

Stefan

Nice fix Rog!

Looks like a different set up on my 4/4 with the Mazda box ?

On the subject of the clutch fork, keep an eye on the boot. These only seem to be held in place by its self in the rubber rebate. Mine fell in slightly and perished, the new one is now stuck in place with adhesive to avoid it happening again.

Here is the part number if anyone needs a replacement.

That’s an interesting pic Craig. I knew the box sat further back in the Sigma as I don’t think the Sigma has the sloppy extender linkage that the +4 has. But it looks like the bell housing casting has one of the slave cylinder fixing bosses machined off too and a blanking plug. So where is the slave cylinder on a Sigma?

I have no idea Rog i will check tonight. I am sure someone will come along soon though and let us know.

Edit..

Is this it here to the left ?

Rog,
In the parts book the 4/4 has a concentric slave.
Cheers
John

As can be seen, there isn’t room for the stock Mazda slave cylinder on the 4/4 as the box is slightly further back and the slave would foul on the chassis.
So, what we have on the 4/4 is a coaxial slave cylinder mounted inside the bellhousing. This is good and bad I guess. Good is that it directly acts on the thrust bearing without linkages. Bad in that it cannot easily, if at all, have the fluid flushed out at the same time as the brakes. Also, if it fails, it is an engine out job!
Having once owned a MX5 I know that the standard external slave had poor reliability but was cheap, readily available, and easy to change.
Back to the coaxial item … I have spotted a bleed nipple on my car in-line on the clutch hose so that could be used for bleed and a partial fluid change. I do note that it is difficult to access though!