Water Pump Housing Shims - When are they needed?

[infernosg]

Originally Posted by FC Zach

Did you measure with or without the housing gasket?

The gaps were checked with everything installed and torqued "reasonably tight." Without the shims I had complete contact all the way around at the housing-to-iron interface. Without the shims a I did have a small gap at their location (<.005 in.) but I think this would disappear when the housing was properly torqued down.

Mazda does list another P/N for the shim (there's a VIN split for the S4) and perhaps it's a thinner design. I may order those to check in the future since I won't be starting the engine for some time and it's pretty easy to install them.

[infernosg]

Originally Posted by infernosg

The gaps were checked with everything installed and torqued "reasonably tight." Without the shims I had complete contact all the way around at the housing-to-iron interface. Without the shims a I did have a small gap at their location (<.005 in.) but I think this would disappear when the housing was properly torqued down.

To elaborate on this I checked for clearance again after I'd torqued down the water pump bolts and the nuts on the three of the five studs that go through the housing gasket. Without any torque on the remaining nuts I couldn't fit a .002 in. feeler gage between the water pump housing and front iron at the other locations. I'm sticking with my conclusion that I don't need the shims in my application.