Re: lower unit
I know it's been awhile since this was posted, but I just got a lower unit off a guy that was selling parts from his house, and oddly enough....be would take it back 30 days after purchase if it did'nt work. It was for my Merc 25, got it for $275. First thing I did before I gave him the money, check the driveshaft for damage or wobble (rag over the slines, with a pair of vice grips to turn it fast enough to see wobble), put my prop and nut on the prop shaft (had it with me) and spun it. Looking right at the end of the shaft for wobble. Removed the old water pump (threw it away..) and looked down at the seal for corrosion/damage. Looked into the exhaust port for damage. Checked for cracks, put it gear and checked for engaging. Did a pressure test with a handheld pressure gun with a gauge to 15psi (I keep a compression tester in the truck also), checked out. I paid the guy and took it home.
When I got home, stripped all the removable parts off of it and cleaned the heck out of it. Replaced the trim tab and installed a complete water pump kit. Greased the entire drive shaft (keep water off of it) and greased the prop shaft. Installed it then drained what was left of the oil in the lower unit. Replaced it with Quick Silver high performance lube with all new fiber washers behind the plugs. Readjusted the shifter linkage on the motor so it would hit all the gears nice and tight. Ran the crap out of it for about 2 days then drained it again. Checked the lower unit for leaks. Replaced the oil, and new fiber washers (looking for water or metal flakes in oil). Next service will be next year.
