Broken prop shaft??

[88SEVILLECC]

Sorry for the long post. I need help in troubleshooting my lower unit.<br />My first time on Barkley Lake, water went from 30 plus feet to 2 feet in half a boat length. Only moving 5 mph or less so drive rode over the rock and came down on the prop. Engine runs fine but no forward or reverse. Towed in to ramp by another great boater. <br />Have the boat home so it is time to figure what is broken. <br />1988 4.3 LX with Alpha 1.<br />Have placed it in forward gear and spun the prop CW and hear the dogs ratchet. Turn it CCW and it locks up like I expect but I can keep on turning it CCW. I thought it was supposed to lock up completly when this is done but am not sure. It works the same in reverse. Opened the upper gearcase cover and bumped the starter to see if the upper was still connected and all looks good.<br />The question is should the prop shaft lock up completly when the drive is placed in gear and the prop rotated backwards?<br />Could the prop shaft or the input shaft to the lower unit be broken? I am getting ready to pull the lower today anyway. Prop has to go to the shop. Some vacation this is turning out to be.<br /><br />Thanks for a great forum.<br />John

 

[viperry Scarab]

Re: Broken prop shaft??

when it locks up does the engine stall at all

 

[FreeBeeTony]

Re: Broken prop shaft??

When you turn it CCW in fwd and it locks up but continues to turn look at the upper gears. This should tell you if the lower is still connected to the upper.

 

[K Hultgre]

Re: Broken prop shaft??

Is the prop hub slipping ? <br />Does the prop nut also continue to spin when turning the prop CCW in forward gear ?

 

[88SEVILLECC]

Re: Broken prop shaft??

The lower unit has been pulled and the splined end of the drive shaft that goes into the upper gearcase was twisted off at the o-ring groove. I was hopeing for a spun hub or some other easy problem but parts are on order for repairs. Any hints on replacing the drive shaft without all of the fancy tools? Shimming for proper penion gear hight is the part I can't figure out. The rest of the job doesn't look too bad. It also took out the seal in the upper where the shaft slides in. I'd rather be on the water!!

 

[jimmbo]

Re: Broken prop shaft??

That's what insurance is for.

 

[seahorse5]

Re: Broken prop shaft??

It is common to break the driveshaft if you hit something just right. Sometimes the splined end with the oring remains in the upper shaft. Use a pick to remove the oring and if you are lucky, you can pry the splined part of the shaft out. If not, then drill and tap for a bolt and use that to pull the shaft piece out.

 

[FreeBeeTony]

Re: Broken prop shaft??

I resealed my entire drive (pre-alpha) and replaced the gears and bearings (including the carrier) in the lower unit w/o any special tools. As far as the shimming goes, I just replaced the shims the way they were originally and it seems to be fine. Have about 40 hours on it without any problems.

 

[88SEVILLECC]

Re: Broken prop shaft??

I got the splined end out without much problem. It wiped the lower seal in the upper unit though. Just one more part to replace. I am hoping that there won't be any isues with the new driveshaft. I am going to use the old shim setup and hope for the best. Thanks for your replies<br /><br />John