Trigger Wheel, shrink fit vs. bolting/welding?

[alhbln]

After talking to my machine workshop i opted to shrink fit the trigger wheel, as the guy there assured me that a shrink fit is quite robust, as it can even be used to fit gears on a shaft. The trigger wheel was machined on a late so that the inner diameter is 1/10 mm smaller than the (machined) outer diameter of the balancer. The trigger wheel was then heated to ~300 C and the balancer put in the deep fridge for 30 minutes to prepare the fitting. That worked out quite well.

Now after cross reading about possible issues with loosing the trigger wheel i wonder if a shrink fit is sufficient for a trigger wheel. What is your experience with a shrink fit?

[brentp]

It would seem fine- especially considering the fact there is no torque applied to the trigger wheel except for it's own inertia.

That said, I would personally install at least one locating pin

[alhbln]

Good morning,

will do, should be easy to add.

Thanks,
Adrian

[Gassed'58]

For your information starter motor ring gears on the flywheel are shrink fitted and these carry very large loadings. I would suggest that the trigger wheel would be fine done this way.

[BRUCEROE]

The picture looks like the trigger wheel is on the outside of the harmonic balancer. On several of mine, the old rubber has let the outside slip, loosing the timing mark. But in this case, the engine would stop. Bruce Roe

[Ken555]

I fitted my trigger wheel in the same way, well apart from Liquid nitrogen as a coolant.

They also machined on a slight taper to the crank pulley and trigger wheel (you can't see it by eye), this means that when fitted you would need it to expand to come loose.

The original Sierra wheel is fitted this way.