Raymarine auto pilot - linear drive foot mounting worn bearing

[searocket]

We had a persistent clunking sound from the steering when sailing downwind under autopilot in a moderate seaway.
Investigating below deck revealed a lot of play in the bearing on the drive foot mounting of our Raymarine linear drive (second photo), this seems the likely cause.
There is a very small amount of movement in the rudder bearing (Jefa self aligning type) - but I think this is too small to account for the very obvious clunking.
Has anyone had this problem? If so how was it solved.
There is a replacement mounting foot available as a spare (first photo) but it's £180 - so I am a little reluctant to order one without some reassurance it will solve the problem.
thanks

 

[MontyMariner]

Mine's 22 years old and ok. Which bit of it has worn?

 

[searocket]

There is a lot of movement between the silver aluminium piece and the fixed pin of the drive foot . The removable pin with the R clip that secures the drive unit seems ok.

 

[PaulRainbow]

There is a lot of movement between the silver aluminium piece and the fixed pin of the drive foot . The removable pin with the R clip that secures the drive unit seems ok.

There should not be any wear there, as the pin should be fixed within the main foot, with the aluminium part pivoting on the pin. I would check that the aluminium part isn't seized to the pin, causing the pin to rotate in the foot, causing the wear.

Would be an easy fix for a local machine shop, drill the foot and press an insert in, with an interference fit for the original pin.

 

[rotrax]

Or, just go slightly oversize.

Bore to the next size up, use a new pin to suit.

Lube regularly in future.

 

[Amlov]

We also have a bit of noise from the linear drive, similar to you describe, and which appears to be from play in mounting. This was after 5-6 years of service covering about 1000h/y, which I thought was premature wear.

Unfortunately, although the wear is not huge, there isn’t much metal in the casting and drilling/bushing would significantly weaken the mount. As a result, we have decided to live with it for now.

 

[Cardinal]

I also suffered this problem and replaced the mounting having first slightly realigned it which I hoped would reduc the likelihood of further wear. I also was alerted to the problem by the annoying knocking which disturbed my sleep at times. I have since annually greased the mounting but suspect it is still not entirely satisfactory.

 

[KompetentKrew]

There is a replacement mounting foot available as a spare (first photo) but it's £180 - so I am a little reluctant to order one without some reassurance it will solve the problem.

I would imagine a local fabricator could make a better quality replacement in stainless steel for comparable money.

I have a tiller pilot and the Raymarine "pedestal assembly" into which the actuator's butt pin drops is two pieces of aluminium, one of which screws into the other (pics: 1, 2). When the thread wore out and it would no longer hold together I noticed that the previous owner had used PTFE tape on the threads to try and reduce play in the past. I was a little bit shocked by the price of the replacement, but it wasn't that much more expensive than the Raymarine spare and I have a lot more confidence that it'll last.

Surely, though, the first step is to disassemble and identify where exactly the play lies?