posted 05-09-2012 04:33 PM ET (US) Hi. I will be attempting my first [outboard engine] water pump impeller change. The manual states to use Loctite 271-red on the impeller housing bolts and on the gear housing retaining bolts. Is this necessary? Or, can I just use marine grease to prevent seizing? [A reply will be] much appreciated.
contender
posted 05-09-2012 08:12 PM ET (US)
DO NOT USE THE LOCTITE. You want to be able to change the impeller again, and the corrosion alone sometimes seizes the bolts in place you do not need any help from loctite trust me. I like and use the Triple-Guard grease from Evinrude.
whaler1234
posted 05-12-2012 04:10 PM ET (US)
Well not having good luck so far... My lower unit does not want to separate after removing the 5 bolts. Does anyone have any good advice on how to get this off? I gave it a few raps but I don't want to damage anything.
onlyawhaler
posted 05-12-2012 06:56 PM ET (US)
Are you sure you have removed all the necessary bolts. Not knowing what you have makes it harder to know. I recently dropped my gearcase (Yamaha) and there was one more bolt under the the zinc anode on the cavatation plate.
Onlyawhaler Sterling
whaler1234
posted 05-12-2012 08:34 PM ET (US)
I believe I only have 5 on my 2004 Mercury 4stroke on my 170 Montauk. I've googled the answer and see a variety of results. Some say to hit it with a rubber mallet or wood block. I'm not certain how much to try hitting it with a hammer. I'm going to try using a bolt and stud to force the unit off.
contender
posted 05-12-2012 09:14 PM ET (US)
Not sure about Mercury, but I know Evinrude's have a bolt under the adjustable skeg on the lower unit, two bolts on each side and two under the cavitation plate(6 total) (one under the skeg). Have you disconnected the shift linkage? Try shifting the engine in gear and move the prop back and forth. Also the lower unit needs to come off straight, make some wood wedges and put one it the front of the unit and one in the back, and take turns (front and back) hitting the wedges with a hammer. When you get the lower unit off, Make sure you clean the splines on the drive shaft and use plenty of marine grease when you put it back together...
SaintGeorge
posted 05-15-2012 04:20 PM ET (US)
Two nuts/studs on each side--- visible.
Another underneath the trim tab (zinc). Remove the trim tab for access.
The shift mechanism is a rotating shaft. The junction is a spline. It pulls apart when the lower unit is lowered. There is not linkage requiring special disconnect work. This is visible at the front top of the lowerunit. Watch alignment here when you reasembly. You may need to slip a screw-driver in from the side to hold the upper shift shaft and to line up the spline fittings.
The fitment around the studs after removing the nuts is pretty tight. Any slight corrosion there makes it seem stuck. It may require some penetrating oil and GENTLY tapping and prying to get things apart. I clean this up and coat with the Mercury "Special 101" before reassembly.
Re: the Loctite Red. I think you can use this if you wish to follow the manual exactly. It comes apart OK. They use this to fill and seal the threads from water. Old days they used to use gasket sealer (e.g. "Perfect Seal") I use the Mercury/Quicksilver Special #101 for this application. It is essentially waterproof and doesn't harden, but it does cost a LOT more than the Loctite... (like more than $20 per 8 oz. tube) which may explain the locktite recomendation from the manual.
I use the Mercury/Quicksilver "Anti-Corrosion Grease" on the splines. I have used the Evinrude/Johnson "Triple-Guard" grease (red) and that worked pretty well too!