Lower Unit Blues 150 V6...swap a V4 looper unit??

[deviljohn]

Man, the weirdest thing occurred w/ my problematic 94 V6 150 Johnson Ocean Pro today....had motor up while anchored on a sand bar...noticed a 3" crack in the lower unit housing..above the gear case on the port side, just behind the V, just below the cavitation fin....what the &^%$^% did not run aground...did not notice any impacts what so ever...yes oil leaked and water in, assuming unit is shot...limped it back to the ramp...saltwater oozing out..big bummer. Only thing I can think of is hitting a submerged chunk of river flotsam..ie a 6x6 or something...didn't notice any impact that could have done that...front of housing doesnt look as if any impact like that could have occurred...

fatigue?? stress crack dunno but it's a gd mystery..

anyrate I have another lower unit that came off a 1985 140 HP V4 Evinrude...both are 20" shaft, anybody aware if I can swap this one on?? Guess I can pull the existing and tell, just figure I'd ask the gurus before I made the effort, thanks in adavance..

 

[HighTrim]

Re: Lower Unit Blues 150 V6...swap a V4 looper unit??

Im pretty sure I have heard Dhadley mention that that V4 gearcase will bolt up and is usable, although you'll most likely have to change props because of the gear ratio difference.

If you do this be sure to use the best full synthetic gear lube available.

 

[sammy29926]

Re: Lower Unit Blues 150 V6...swap a V4 looper unit??

Hi Devil john,
somebody close byme... I am located at Hilton Head Island, Sc and i am sorry you had that problem..
Sammy

 

[Dhadley]

Re: Lower Unit Blues 150 V6...swap a V4 looper unit??

You're in luck, kinda. The 1985 V4 loopers used a V6 type gearcase. The size of the unit and the propshaft are the same as a V6 but the gear ratio is different. Your existing prop should work (shaft should be a 15 spline) to try. As HT mentioned you may have to change props to a different pitch.

You'll have to change shift shafts naturally, no big deal. You may have to shorten the splines on the driveshaft and possibly reduce the OD of the area right below the "O ring" groove. You won't need an O ring, it'll already be o the crankshaft.

The other option is to change the driveshaft but to do that you'll need to take the unit apart. At that point it may be easier to find a used gearcase from another 60* motor.

 

[deviljohn]

Re: Lower Unit Blues 150 V6...swap a V4 looper unit??

Thanks fer the tips fellows, I'll get into it as soon as Hanna blows my shop down...shame is it's fish-on around here and I got a perfectly good hole in the water that seems to have a lemon rebuilt 150 on it..always the jon boat to rely on....I'll post a pic of that lower unit crack...it's still baffling me

JD