broken drive shaft

[swright]

I have a 1989 Mercury 135 v6. Last weekend while running great for a couple of hours, it felt like the prop slipped a bit, the a minute later the the engine lost its drive. First I thought it was a slipped hub, but after I removed the gear case and water pump, I saw the broken drive shaft at the base where it goes into the gear assembly. Is this something that can be repaired with a new drive shaft, or am I looking at a new lower unit? What could have caused this? Have these been known just break on occasion. I did not hit anything or hear it break. Could this be deeper than just a broken drive shaft? I spin the prop with my hand and cannot hear any metal.

 

[swright]

Re: broken drive shaft

 

[Chinewalker]

Re: broken drive shaft

In general, driveshafts don't break on their own. When they go, the primary reason is something seized in the gearcase - either a bearing locked up, or a gear lost a tooth and the broken piece sandwiched between the other teeth. With the motor running and the gearcase stopping, something has to give - the driveshaft. They can also break if you hit something, particularly if you're using a prop with a solid hub. It doesn't sound like that's the case with your description. I'm betting on the broken gear - bottom line, you'll have to get the gearcase rebuilt or replaced...<br />- Scott

 

[Kenny Bush]

Re: broken drive shaft

SWright, fix that puppy......You can find a driveshaft used pretty cheap... Could be the lower gears too..... Anyway, it all can be fixed cheap.... Call Cap'n Macs Boat Salvage in Austin. They will have it. Several mercs will interchange. Or if your not mechanically inclined, take it to the dealer. Goodluck....BushCat