I HATE those pin drive propshafts.

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Yesterday I did some Hydro-Therapy. Cloudy and drizzle yet after 15 minutes of therapy, the sun came out. Ran the boat for about two hours then headed for the dock. Great day! Fifty feet away I came off plane and as she settled deep, the engine stalled. I knew I was low on gas so I thought I cut it too close and ran out.

No big deal--paddled to the dock. Backed the trailer in and getting ready to load the boat, I looked in the water to see an empty propshaft. CRAP!

Due to a broken tailcone or cotter pin, when the load came off the prop, the forward motion of the boat pulled it off the shaft. Double crap! That was my favorite bronze prop. Michigan 2 blade 10 1/2 diameter X 15 pitch, fully cupped. Bought for me as a gift in 1968 for 12 bucks new and five bucks for cupping at the prop shop. Almost impossible to replace. Lost in only 5 feet of water but a soft mud bottom---gone forever.

Since I don't have another plastic tailcone, I slipped on an aluminum Michigan three blade 10 3/8 diam. X 13 pitch. I used a 1/4 inch Allen-head bolt and nylock nut as a thrust pin. Long bolt with a plain shank that passes completely through the hub, and excess threads cut off.

Then for added safety, where the tailcone would screw on I added two washers and a 1/2 inch nylock nut. Two washers because I didn't have one thick one and the nut would not screw down all the way. Now, even if the thrust pin breaks, the prop will not come off. Wish I had thought of that before, but I have had years with no problems even though I never liked the thrust pin arrangement.

Those of you with Chrysler or early Force 35-55 horsepower thrust pin drive may want to think about using this modification.

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oxmax360

Seaman
Joined
Sep 10, 2012
Messages
61
Re: I HATE those pin drive propshafts.

Dang sorry to hear that you lost that prop, but a very interesting mod.
 

redstrat

Petty Officer 1st Class
Joined
Dec 29, 2011
Messages
202
Re: I HATE those pin drive propshafts.

That sounds like a real lose. Have any scuba buddies?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,083
Re: I HATE those pin drive propshafts.

Time for an underwater metal detector???

The harbor and chanel that leads out of Baltimore can be as much as 8 ft of MUCK!!
Trash bags,body's, boats,liquor bottles etc.
I used to do marine salvage,clean boat bottoms etc.
Had a guy ask me to get my scuba gear and go get his 15hp Johnson.
That was in the early 80's IT"S STILL THERE!!!
 

catfishcarl99

Senior Chief Petty Officer
Joined
Apr 25, 2012
Messages
723
Re: I HATE those pin drive propshafts.

intresting frank. listing to my tale. i had a slipping clutch dog a few years back. the engine was banging every 4-5 seconds at WOT. i had no idea what was happening. i thought it was an air/fuel problem. guess how many props the slipping out of gear cost me???????






3. yep. first one came off after a minute or two of trying to figure out the problem. came off plane and gone. got a new one at $140. and went out with a buddie driving while i tried to adjust carb. bang-------------bang----------------bang-------------- back to neutral and no prop. got another same deal. it went on trailer and i got with a boat mechanic on a fishing forum and was explaining it to him. i was usung the word cough for a few weeks. he kept saying the carb. then i finally posted it was going bbbbbrrrrrrrrrrrrrrrrbang!bbbbbbbbrrrrrrrrrrrrrrrbang. he said why didnt you say bang the first time. thats prob a bad clutch causing it to slip out of gear. $85 later i had a new dog and problem solved. $400+ on the credit card in props. i havent had any problems since and have since got 3 spare cone nuts off ebay for $5 each and a bunch of stainless cotter pins and i buy used props now lol. i will definatly keep this in mind.
 
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