Logo
FULL SITE MENU

50 HP Lower Unit Drive Shaft

B

Bob in Tennessee

Contributing Member
I have a 1977 500 with a busted lower unit housing. I bought a replacement on ebay that has a drive shaft that is 3" shorter than the one I have. Looks like my choice is to swap drive shafts. My question is how do you remove the water pump base? There is nothing to grab and it is preventing me from lifting the drive shaft.
thanks
 
Stop----there is usually a 5" difference in long verses short driveshafts.-----There is a nut / bolt on the bottom of the driveshaft that must be removed.----Are you sure you have the correct replacement?----Any pictures ?
 
I removed pinion gear bolt, but the water pump base is preventing me from lifting the drive shaft out. I thought this was something I could handle but I may take it to a local mechanic that works on old Mercs. He warned me that swapping shafts may require shimming to achieve proper fit.
thanks
 
Yes , you need to look into shimming.----Have you determined why this unit had a 3" shorter shaft ?-----Is there a flush plug that is holding the pump base ?
 
I ended up buying a lower unit that had the correct shaft length. Thanks for your help. My issue now is correctly installing the lower unit. I have started another thread if you have a chance to view.
thanks
 
Back
Top