Does anyone have any tricks to replacing the lycoming tach seal? I need to do one and I see that spruce carries a tool but I am unsure of how well it will work. Tim
Haven't done one for a while but shouldn't be too difficult. Not sure what the tool is to remove them insitu. Use a couple of picks to pry the old seal out. Dont damage the housing. Lube the shaft then tap the new seal in gently using a socket or sleeve etc.
Should work a treat.
I’ve used a close quarters right angle drill with a short number 40 drill bit..drilled two holes into the seal, screwed in a couple number 6 sheet metal screws then slipped a short tiny torx head bit into the end of the tack drive shaft to pry against using 1/4” key stock as the lever.
I got that tach seal swapped this last weekend, I did not have to swing out the mount and it took all of 3 minutes to pull out the old seal once I got the oil filter adapter unbolted. Super easy and fast. Worth every penny in the time savings to get it done!
My technique is similar to Marks. I drill 2 #50 holes 180 degrees apart, heat the housing with a torch to expand the aluminum, then put the tips of a pair of straight external clip ring pliers in the holes, squeeze and twist.