Metal shavings in 81 black max 175hp lower unit. What to all replace?

[444]

Got water(edit, actually is metal shavings) contamination in the lower unit of my 81 black max 175hp. It will go into gear still but will slip out of gear if I try to put any thrust on it. Should I just do all the bearings and seals or is there anything else I should look at while I'm in there? I'm very mechanically inclined but I've never worked on a lower unit before, although I do have a shop manual for it. Thanks, 444.

 

[Maxz695]

Re: Water in 81 black max 175hp lower unit. What to all replace?

Re: Water in 81 black max 175hp lower unit. What to all replace?

Water has 4 ways to enter the unit. 1 through the gaskets on the fill drain screws 2 through the waterpump lower base o ring seal 3 through the shift shaft seal ans 4 through the prop seal. I would chang the screw gaskets first being the simplest of them all. do not add oil. Test the unit under compression and see if it hold it without leaking. If it hold fill it with oil and get boating if not add oil and retest and see if you can find the leaking oil. That is what must be repaired. My bad --> OK 5 ways you dan,t have any cracks in the case right?

 

[Faztbullet]

Re: Water in 81 black max 175hp lower unit. What to all replace?

Re: Water in 81 black max 175hp lower unit. What to all replace?

Slipping out of gear is not a water in oil problem, that a rounded dog, gear or unit frozen and carrier is pushed to rear problem. You will need a vacuum and pressure tester to see where leak/s are, and do not hammer out the spanner nut with hammer & punch as you can crack the case sidewall. Follow the manual to replace all the seals as the seals are 20+ years old!

 

[444]

Re: Water in 81 black max 175hp lower unit. What to all replace?

Re: Water in 81 black max 175hp lower unit. What to all replace?

Well after actually draining the oil, the sludgieness I thought was water is actually metal shavings! I will pull it apart tomorrow if I can figure it out and post some pics.

 

[Gomer50]

Re: Water in 81 black max 175hp lower unit. What to all replace?

Re: Water in 81 black max 175hp lower unit. What to all replace?

Possible shift shaft pin worn down,shifter cam,and as faztbullet mentioned your clutch dog.Your forward, reverse and pinion gears may have some damage as well.Best of luck to you.