New prop came loose

[andrewterri]

I put on a new 4 blade turning point and tightened it correctly last summer. I checked at times throughout the summer and it just had the normal play for a alpha one mercruiser. Today while changing the gear lube i noticed the nut was still tight on the thread due to the nylon lock, but the brass looking thick washer was loose and was the locking tab ring. They were loose by 1/2 to 1/2 inch. What could cause this? Could it be from the insertable hub tightening up?

 

[harringtondav]

The good news is your prop didn't come off. Better news is you caught a problem early. Did you install the SS star lock washer and bend the tabs into the splined brass castle lock ring?

Tightening the prop nut and SS lock washer can be a little tricky. If you're not careful the lock washer can grab the brass retainer teeth and stop turning with the nut. Then you tighten the nut on top of the lock washer, not in it's hex pocket. Shift engagement inertia will eventually cause the nut to align with the hex pocket and introduce play.

An interchangeable hub will squeeze to position with the recommended 50 ft lb of nut torque.

 

[jimmbo]

Is the hub still intact?

 

[andrewterri]

Ya everything looks good. you can move the prop about 3/4 inch of slack or play. everything is tight it just didn't tighten to the prop or it did and something settled. I am a little confused on what you mean by tighten the prop nut but not when its in the splined washer. And yes i bent the tabs on the washer. does anyone have a picture of the prop and the order of washers and nuts? the parts catalog does not she where the prop goes and what order everything goes in. Thank you guys for your help.

 

[andrewterri]

Yes the hub is still intact from what i can tell. We took the boat to the lake last week and everything worked great.

 

[jimmbo]

can you post some photos, or a video showing this?

 

[Chris1956]

Don't use the motor until you get this sorted out. If the thrust washer is not working correctly, or you have the wrong one, the prop will hit the gearcase housing and ruin it.

A Mercruiser should have a thrust washer that goes on prop shaft first, and sits on the taper of the propshaft. You might need one customized to the Turning point prop. See if the rear edge of the thrust washer recesses into the base of the prop.

Newer Turning point props have a one piece rubber/plastic hub with a splined brass center. These are custom to Mercruiser, and you need the right one. These fit into the prop casting.

Slide the prop and hub onto the propshaft. You then should install some kind of spacer. I would expect a silver piece of metal with splines inside to match the propshaft splines. Make sure those mate. Over that goes a spider washer and Nylon centered brass locknut.

Tighten the nut down. When the nut is nearly tight, pull the spider washer onto the nut, mating the recess with the nut, and tighten some more. Block the prop with a 2X4 and tighten securely. Bend 3 prongs of the spider washer down to hit the spacer.

 

[harringtondav]

To add to Chris' comments above. Thrust washers and locking rings are not all the same. They are prop specific. Each has a hub that passes thru the prop bore and contacts only the hub, leaving a small clearance from the end faces of the prop. The intent is to clamp only the hub. If either contacts and clamps on the prop, you loose some of your hub's designed break away protection when striking an object.

 

[Bt Doctur]

It sounds like the thrust washer went missing at the install and the prop ground into the castle nut in the housing
https://www.youtube.com/watch?v=UA1yshDrMME

 

[andrewterri]

If i can get the pictures to upload here they are. You can see the prop nut and washers that i am using. The other two pictures are of me pulling and pushing on the prop so you can see how much slack there is. I can not figure out how to upload the photo. I make an idea book with the photo but can not select it. If i try and upload from the computer it says the photo is to large.

 

[andrewterri]

I watched the video Bt put up and all those pieces are there. I am going to try and upload the photo from my phone and see if that works.

 

[andrewterri]

Update... While everything was secure and tight when i put the prop on I went to take the prop off and check the thrust washer you guys are talking about and the nut was loose and not tight at all. I took it off and the thrust washer is there and looks fine. I think the hub was not put in all the way when i install the prop and through running it seated itself but left the prop with slack, Does that sound plausible? Prop nuts wont just come loose will they? Thank goodness there was a nylon lock in the nut or i would have lost the prop last week and been stranded.

 

[jimmbo]

The inserts don't often seat, especially when new, that is one of the reasons there is a Torque Spec when installing a prop.
There is supposed to be a Positive Lock(cotter pin or tabs) to prevent the Prop Nut from backing off. The nylon locknut is sort of a backup,
There should be a shoulder on the thrust washer that fits inside the prop hub. Does it?

 

[andrewterri]

Yes there is a shoulder all the way around the thrust washer that fits inside the hub. It is a perfect fit in the hub. I will say the order of what i have and what im using according to the nomenclature from the mercruiser parts catalog . Thrust washer, prop, washer splined, tab washer, prop nut. Now what they call the washer splined is about a 1/4-1/2 in thick brass washer. The tabed washer is the one that has a place for the prop nut to set in and i bend some ends into the brass washer.

 

[Watermann]

I have a turning point prop on my OB motor and a Quicksilver black diamond on my Mercruiser. The TP hub does have more resistance and stops short of being seated where the QS bottoms out more easily. I noticed this when I put my TP prop on but it seated correctly as I torqued the prop on to 50 flbs. Did you use a torque wrench?

 

[andrewterri]

Yes i did. I always follow torque specs because doing so usually avoids stuff like this. i remember when i put the hub into the prop it was very tight and hard to get seated. I think that is what happened to me. It was not seated all the way and running it put enough pressure to fully seat it which left the prop loose. I am not crazy about the design. I like the solas prop where the hubs are built in.

 

[QBhoy]

Hi
ill admit I haven’t read all the replies because I’m on the phone version just now...but I’d bet my bottom dollar that you’ve likely tightened the nylock nut against the hex washer outwith the nuts seat position inside the insert of the hex washer. Easily done.

 

[andrewterri]

QBhoy it is very possible i did that. I am usually very particular about attention to detail but we all make mistakes.

 

[QBhoy]

Yeah. Wouldn’t consider myself daft with these things, but I’ve done it more than once. First time I had the same issue as you. Second time I remembered to check I hadn’t done it again. I had. Easily done.

 

[QBhoy]

In particular referring to the merc flo torq hub nylock nut and locking tab washer. More commonly done when the nut tightens down off set to the hex flats of the washer. You know what I mean.