Prop / prop shaft wrong on '67 V4 60HP Evinrude?

Rebuilt it and it was fine at low revs, but came out of gear at medium revs after a while and shortly got to stage it wouldn't hold under more than low speed throttle. <br /><br />I thought it was shift linkage problem but it turned out that when it came out of gear the drive pin seemed to have shifted back a tad and knocked the inside lobes off the retainer nose cone thingy and then broken it up until the drive pin fell out. Probably made a lot worse by over-revving when it popped out. That's what started to happen with the replacement retainer before I fixed up the clutch.<br /><br />Fixed the clutch up by recutting the clutch dogs and the mating surfaces on forward (without going through the case hardening).<br /><br />On closer inspection I can see grooves inside the prop hub at right angles to the drive pin and running parallel to the prop shaft. They're wider at the back than the front (front is the part nearest the transom).<br /><br />I reckon there's a bit of vibration at some speeds, mainly midway between low speed and about a third throttle.<br /><br />Are these prop grooves normal? They'd allow the prop to move very slightly from side to side on a static test. I'm wondering if they're allowing some movement in forward that is causing the vibration (or maybe I'm imagining the vibration, but something doesn't sound quite right to my ear).<br /><br />The drive pin is a very loose fit that will fall out under its own weight. A couple of outboard mechanics have told me this is right, but why would it have one chamfered end if it's intended to be so loose?<br /><br />It looks to me like one explanation would be that as the drive pin holes wear this allows the hub to move on the shaft and create the grooves inside the hub.

Re: Prop / prop shaft wrong on '67 V4 60HP Evinrude?

I'm confused as to what you are talking about when you say you knocked the lug's off. Are you asking about the the bearing, and seal retainer in the back of the gear case that has four outer lug's, or are you talking about the prop nut. What is your prop nut made of? To answer your question on the drive pin, a loose fit is normal, as is a slight side to side play in the prop when mounted on the shaft. Are you sure you have the correct prop, and nut? What does the inner hub of the prop look like?<br /><br /> There were two gearcases offered on this engine, standard, and heavy duty. The heavy duty is split on the prop shaft center line. Which do you have? These cases don't share the same prop nut

Re: Prop / prop shaft wrong on '67 V4 60HP Evinrude?

R. Johnson<br /><br />Thanks.<br /><br />Sorry for the lack of clarity.<br /><br />The prop is held on by the drive pin which in turn is held captive by a black plastic nose cone which is held to the prop shaft by a split pin. No nuts involved and no provision for one i.e. no thread on the shaft. <br /><br />The nose cone is like the nose cone on a WWII fighter prop, with the point pointing backwards away from the transom. It is illustrated as a "retainer" on the diagrams I have. It has a metal bar across the inside of the pointy end which fits into a split in the end of the prop shaft so that it turns with the shaft.<br /><br />The split pin goes through the nose cone and the prop shaft and stops the nose cone moving forwards or backwards on the shaft.<br /><br />The lugs on the inside of the nose cone are one either side on the inside 180 deg opposed. Sort of squarish projections. They just clear the drive pin i.e. sit just behind it. I can't see what function they're supposed to serve as it appears to be the outer casing of the nose cone / retainer at its end nearest the prop that stops the drive pin flying out under centrifugal force as the prop spins. The only way the lugs could be damaged is if the prop moves back maybe 1/16th" to 1/8th" or the nose cone moves forward the same amount, or if the drive pin has enough room in its holes to get on an angle so that its outer end moves back the same distance.<br /><br />I think this is the standard gearcase. It comes off in one piece and the drive pinion projects through the top and everything is accessible and removable only by removing an end cap at the prop end of the gearcase which is a light pressure fit and has screws (I think 4 but it's a few weeks since I pulled it apart) going into a retainer plate behind the end cap. There is another gearcase on this model which is a two piece or split affair, but I don't have the manual handy and I can't remember exactly how it differs from mine. It's probably the split one you're referring to.<br /><br />The inner hub of the prop is metal. No splines or anything else, just a round tube that fits over the shaft and is able to rotate only because the drive pin holds it.<br /><br />The grooves in the hub are shallow and 180 deg opposed. They appear to have been caused by the prop being able to move more at the back than at the front (transom end) of the shaft.<br /><br />I've checked the shaft and it is within one thou of an inch the same diameter all around measured at three points along it with a digital vernier caliper accurate to one thou, so I don't think the shaft is the problem.<br /><br />There is very slght play in the prop allowed by the slop in the drive pin fit, but there is also play in a different direction allowed by the grooves inside the hub.

Re: Prop / prop shaft wrong on '67 V4 60HP Evinrude?

Are you missing a thrust washer?

Re: Prop / prop shaft wrong on '67 V4 60HP Evinrude?

DJ: Yes he is!

Re: Prop / prop shaft wrong on '67 V4 60HP Evinrude?

You're both right!<br /><br />I'm missing a thrust washer between the prop and the nose cone, according to the manual.<br /><br />I carefully checked that all the internal parts agreed with the diagram when disassembling and reassembling the gearcase, but stupidly ignored the outside on the assumption that all the parts were there when I got it. Wrong!<br /><br />Thanks to you both.<br /><br />Another lesson learned about checking EVERYTHING.<br /><br />There's still the question about the shallow grooves inside the hub of the prop. Do they matter?

Re: Prop / prop shaft wrong on '67 V4 60HP Evinrude?

Are you talking about "lugs" or notches in the area of the prop near the propshaft seal? If so, they used to use those as a means to cut fishing line to keep it from getting wrapped up on the shaft and damaging the seal. Most of the time, they system didn't work.

Re: Prop / prop shaft wrong on '67 V4 60HP Evinrude?

seahorse<br /><br />I think you might be talking about the notches in the endcap that fits into the gearcase and seals it off forward of the prop. <br /><br />The lugs I'm talking are inside the nose cone and wouldn't cut anything.

Re: Prop / prop shaft wrong on '67 V4 60HP Evinrude?

Tinker2: I don't have one of those nose cones to look at, but I think I know what you are referring to. That brass inner hub is broach cut, and that leaves the grooves your talking about. I'm not sure what purpose they serve, if any. They are nothing to worry about.

Re: Prop / prop shaft wrong on '67 V4 60HP Evinrude?

R. Johnson<br /><br />Thanks.<br /><br />I wouldn't be surprised if putting the thrust washer on stops the prop vibrating (assuming it was) as it should remove all the slop in that area.