Alpha Upper Unit Binding
 

Hi,

Has anyone ever heard of an Mercruiser Alpha upper unit failing in such a manner that it binds and causes the engine to stall?

Cheers,
Chris

The input bearings will seize if not set up correctly or run low on oil.... either way...

are you sure it's the upper?
if not, check the shift plates/switches for proper adjustment.
i just replaced my shift plates, one motor stalls on shift..too much...it's obviously (to me/my work) that the switch needs adjustment, because it works in reverse just fine...
..also, my drives sat dry all winter, i was super-draining them for the switch to synthetic lube, at the initial hand turn they appeared siezed...after a refill, it's all fine...
hope it helps..
c

Hmph, not sure about anything. The prop still spins freely by hand, shifting into/out of gear is fine. What happened is I was cruising along at maybe 3500-4000RPM and the engine stopped. I restarted it and about 15 seconds later is stopped again...only now something is dragging so much the engine can barely crank. I don't think it is an engine issue because the oil is clean and I heard no noises before the engine bound up. I was just curious if the upper drive could bog down and engine while not making any odd noises. The shop I brought it too said no, but some other folks I have asked said that is possible.
Thanks Much!
Cheers,
Chris

generally what happens is that the drive will develop a leak and as the gear lube goes down the upper gears and bearings go dry first and the failure will cause upper to lock up but lower still spins freely and will shift.also the big cause is that if you fill the drive the wrong way by filling with the lube tank hooked to the top screw you develop a air lock and after driving a short time it burps and the lube goes to the lower gearcase and again the upper fails due to no lube either way the lower will have to be rebuilt and sealed due to the metal shavings.hope this helps

pull the top cap of the drive and look at the gears and bearings if it looks good pull the drive and see how it cranks.