Clutch Slave Cylinder Woes

[aviationfred]

I have seen the recent post about a faulty clutch with loose slave cylinder bolts. Keep those bolts tight and by all means, use a torque wrench

When I purchased my 1990, it had 1/4 x 20 all thread and nuts holding the slave cylinder on. Over the years the threads in the engine case had weakened and I had a complete clutch failure. Pull the clutch lever and you could see the slave cylinder physically move outboard. I attempted to make a repair with M8 helicoils. The forward mount hole had been so wallowed out that when I attempted to install the slave cylinder the mount boss in the case broke. I am looking at a few options and directions to solve the new issue.



Fred



Fred

[T Legg]

That sucks Fred. A broken mounting bolt on each half of the case pretty much finishes off your engine. I'm facing the same thing x three on my yellow 1100 that had the chain break. The only solution I can see is disassembly and some very fancy welding and machining. In my case it will probably be cheaper to get another engine.

[FJ1200W]

Epoxy in a stud - possibly even adding the broken piece back in, run a safety wire around for reinforcement.

Proper prep is critical, as you know.

Not sure if you could drill a tiny hole for a small drift pin from the remaining sidewall into the stud - then epoxy it all in place.

If you need a set of cases, I might be able to help you out.

Deal of the day.

[Pat Conlon]

Clean it out (real good) TIG weld in some filler, drill it out (use a drill guide bushing) and tap it.

Paging Carson City Paul, can you make Fred a drill guide bushing so he can keep that new hole centered?

[Carson City Paul]

I could do that. It would probably be a one time use due to soft material (non heat treated steel).

[Carson City Paul]

I have seen the recent post about a faulty clutch with loose slave cylinder bolts. Keep those bolts tight and by all means, use a torque wrench

When I purchased my 1990, it had 1/4 x 20 all thread and nuts holding the slave cylinder on. Over the years the threads in the engine case had weakened and I had a complete clutch failure. Pull the clutch lever and you could see the slave cylinder physically move outboard. I attempted to make a repair with M8 helicoils. The forward mount hole had been so wallowed out that when I attempted to install the slave cylinder the mount boss in the case broke. I am looking at a few options and directions to solve the new issue.



Fred



Fred

The biggest problem with installing helicoils is, you are thinning the wall of the boss and making it weaker (more prone to breakage).
I would only do that as a last resort... if it's not stripped, don't do it.