Loose Prop???

[JacobsDad]

OK I was out washing the boat and getting ready to wax it yesterday and when I did my normal prop inspection and spin by hand I noticed that there was quite a lot of forward and backward movement in the prop on the shaft. After close inspection of the cotter pin and castle nut it was obvious that it had not turned or become loose. However there was a good 1/4" of sliding movement on the prop shaft. it was good left to rigt but would slide in and out on the shaft. I can only assume that this is a very very new issue as there is no real wear on the prop, shaft or seal and lower unit only a loose prop. I cant figure out where the slop came from the hub in the prop seems fine the hardware for the prop seems good and the nut could not have rotated counterclockwise. So I am looking for any advice anyone might have on this strange issue. Have you ever found your prop like this if so did you just take the pin out and re-torque the nut and reinstall the pin or was there some sort of failure that is not obvious to somewhat of a mechanical eye? After applying the correct torque and installing the pin in the castle nut it all seems good. I am truly baffled?? Thoughts.


Jeff

[blazerman]

yamaha has had trouble with this issue and has replaced several lower units where the prop slides too far forward and starts eating into the gearcase. they are supposed to be putting a new two piece thrust washer on to correct this. put a 2X4 between your prop and cavitation plate and snug it up real good. and check it everytime out to ensure that it stays tight.

[mark Z21]

just wondering, could his prop hub kit be slipping to the rear of the prop?

[PRO XS Skeeter]

In the same boat with you. Noticed a few weeks ago and though it was a bad thrust washer. Changed out the thurst washer and ran it Saturday. After the TX i spun the prop and it was rubbing on the gear case. Lots of slack front to back and even some side to side. Have heard that yamaha is replacing some of the LU's for some guys with this issue but i dont know how far back they are going my motor is a 01 modle. I thought i might have a bad bearing inside the housing but i took it apart and everything looks fine from the inside. Cant figure out where the extra slack came from. good luck.

[HAWK18]

I have had the same issue and Yamaha put a new lower unit on mine ( 2004 250hpdi ) , and they gave me a proto type 2 pc. thrush washer, and that has seemed to fix the issue. check your prop shaft and make sure it does not have any chatter marks on it , and the gear case . my prop got into the hex head screws on the gear case. but check with your dealer and see if Yamaha will waranty the washer. I don't think the 2 pc washer is available yet.

[JacobsDad]

Thanks for the input guys, I tightened it last week and fished it all day on Sunday. As of right now it is still tight. I still am perplexed as to where the play could have come from. The nut did not move. I guess the thrust washer might have been partly to blame does anyone have a picture of a normal one and one that has the dreaded issue? I would love to see them. I guess I will call the Yamaha dealer tomorrow I have extended YES till 2010...

Jeff

[Rich Z]

With the prop removed from the shaft, unbolt the carrier retention ring. It is held by two bolts. Inspect this ring for any ware from the prop or from the carrier bolts coming lose. Check the bearing carrier bolts. Ensure they are tight. These bolts have a tendency of coming loose and the bearing carrier will develop an in and out movement. About 1/8” or less of in-out play is normal. Use lock tight on the carrier bolts and then reinstall carrier ring and prop.

[JacobsDad]

if I had shaft play in and out I might think a bearing or the carrier. However there is no more shaft play than ever before. It is like the length of the shaft grew overnight. Really strange, no wear on the lower unit anywhere around the prop.

Jeff

[BuzzB8]

The thrust washer is brass and is softer than steel. If the torque specs aren't applied, the thrust washer will spin on the shaft and wear down. As it wears, it creates play. JMHO, but I also think they had a bad lot (or many lots) of thrust washers. Maybe the brass wasn't made to specs and wore prematurely...but that's just my guess.

[fishendas]

I did not see this post when I posted earlier this evening. The thrust washers are soft and allow the prop to work its way down the prop shaft. See my post. My buddy and I have 6 lower units between the 2 of us, all warrantied by Yamaha. I had 1 thrust washer actually separate like a doughnut and the prop completely destroyed the lower unit in moments. I also had a prop shaft shear inside the gear case and sling a brand new 25T1 prop in to hyper space. I need to find the answer to this problem before I lose my patience.

[21XDC]

I replied to your other post.