Hi All,
I am installing the fan onto a 4.2 motor with new water pump (later hex nose model). This is the unit with the locating pin for the ‘special washer’ which is a thick aluminum piece with a drilling for the pin.
In the photos you will see the fan (yes, I like a yellow fan, for safety), and detail of the locating pin, as well as a score mark from the hacksaw blade that had to be used at removal of the old pin to make way for loosening the bolt, as the pin could not be pulled from the old unit and was an interference fit with the hex head of the bolt. This serves the lock function, rather than a lock washer, I am thinking.
Now the detailed questions for those who know…
- Should the pin be a pressed fit in the recess hole of the water pump spigot, or just ‘located’ there, as described in the shop manual?
- Should the pin be a pressed fit in the special washer?
The approach I took was to match the old pin with a new one at the hardware store. I matched the old one’s taper, but still found that it is not a press fit in either hole. (I’m guessing the old pin was not original, so unsure if these were tapered from the factory. Also, have not found a replacement source for sale.)
I then put the fan and Torquatrol clutch together, placed them on the spigot nose, lined up the special washer’s hole with the spigot’s hole, and tightened the bolt (with a couple drops of blue Loctite to the threads) as tight as it would go, but leaving space in the last turn for the pin to be installed. Dabbed the pin a couple drops of Loctite, and slid it in; a tap of the hammer to ensure it was seated. I then put a counterclockwise turn on the bolt head (a mm or so) to firmly contact the exposed head of the pin, as well as a rap on the pin to give it a bit of bend, and a last counter on the bolt head to be sure.
- Does this sound right, or all cocked up? Recommendations welcome. I would rather take apart and redo while accessible, then to have the fan spin off while motoring. Pins are cheap; radiators not so much. If a press fit is needed, I could get larger size at the hardware store and sand/file the sides down 'til it is a press fit, or…?
Thank you,
Matt