Broken Driveshaft

[zx2max]

I was running a newly purchased boat out of the water with the muffs and they slipped off. I noticed it within about 8 seconds but by then it was too late. I cut the engine but I could smell burning rubber so I knew I probably destroyed my impeller. However, it was much worse. When I dropped the lower unit I realized the driveshaft was snapped in half. I just ordered a used one off ebay but I know nothing about repairing boat motors so any tips on undertaking this repair are greatly appreciated. It's a 1979 Evinrude 70hp motor. I did acquire a repair manual to help me out. My question is what other damage might I have caused with the driveshaft breaking? Anything else I should be checking out while attempting to fix this motor?

 

[racerone]

Inspect powerhead carefully before spending beer tokens on lower unit !!----Should have taken it apart before ordering the shaft.---Gearcase needs to come all apart to replace the shaft.-----Large snap ring pliers required.------Need to shim the parts for assembly.-------Where did the shaft break ?-----I suspect major damage inside gearcase !

 

[zx2max]

Oh boy! I am pretty handy at mechanical repairs but boats are a whole new beast for me. Anything in particular I should look for in the powerhead? I should have all necessary tools including snap ring pliers to do the disassembly. Though I am definitely worried about other damage inside the gearcase. How do I properly shim the parts when reassembling? I'd like to tackle this project versus paying a professional so I can start to learn how everything works. But wondering if I should just take it to a shop. Here is a pic of where the driveshaft broke.

 

[racerone]

Used lower unit is going to be your best option !!!-----If in Canada----evinrudeparts.ca----Is one place to try.

 

[zx2max]

Unfortunately, I'm in the States not Canada. But I will start shopping around for a used lower unit. Thanks for your help!

 

[Crosbyman]

been boating 60 years never seen a broken drive shaft from shock or rust ..... but most will say I am no mechanic.

I stay awake at knight thinking...how is the rest of that engine ??

 

[Chris1956]

Unfortunately I have heard of broken driveshafts on that vintage Evinrude 90HP engines. No gearbox damage, they just snapped. I assumed it was a design flaw.......

 

[jimmbo]

Before you spend money on another gearcase, make sure the Powerhead is not damaged. Scored Cylinders/Pistons and warped Heads are common Features of overheated engines. I suspect that Overheating would be one of the reasons the previous owner sold it

 

[racerone]

See post #2 on spending beer tokens.

 

[racerone]

Had a phone call 42 years ago.-----Fellow described what happened and what 40 HP motor was doing.-----I diagnosed it over the phone.-----Broken driveshaft.------When a powerhead and lower unit are not perfectly in line the driveshaft flexes.----And over time it snaps.-----Fellow drove 1/2 hr to visit.----Showed him the broken shaft in front of his eyes.-----He left shaking his head.-----He used to bring over some moose steaks / venison / carribou whenever he needed more work done.-----That was before internet days.