Water Pump Removal, another idea
Posted: Fri Dec 21, 2018 10:05 pm
The GT750 service manual says to use pliers to pull the water pump shaft. Pliers!
After careful inspection and measurement of the pump shaft, I decided to make a fitting that engages the small impeller circlip groove. I then made a small 'chair' to go over the pump hole. In this way I was able to use a conventional cheapie 2-legged puller to draw out the pump assembly. The pictures below illustrate how this device works—pretty good it turns out. It took me about a day of shop time to make the 'chair' and shaft fitting. I expect that a skilled machinist would take about half that time.
Attached is a .pdf sketch of the fitting and the 'chair'. Pay attention to the shaft diameter tolerance. the circlip groove isn't very deep and the upper tolerance dimension (.3925") is 'size for size' for the slightly corroded pump shaft on my '74 engine.
After careful inspection and measurement of the pump shaft, I decided to make a fitting that engages the small impeller circlip groove. I then made a small 'chair' to go over the pump hole. In this way I was able to use a conventional cheapie 2-legged puller to draw out the pump assembly. The pictures below illustrate how this device works—pretty good it turns out. It took me about a day of shop time to make the 'chair' and shaft fitting. I expect that a skilled machinist would take about half that time.
Attached is a .pdf sketch of the fitting and the 'chair'. Pay attention to the shaft diameter tolerance. the circlip groove isn't very deep and the upper tolerance dimension (.3925") is 'size for size' for the slightly corroded pump shaft on my '74 engine.