Should the Prop be Tight?

gus_jd · Outlaw Joined: 18 Aug 2003 Posts: 140 City: Milwaukee, WI

All--

The nut that holds my prop on is tight, but I can wiggle the prop on the shaft a bit. I don't think I should be able to do this, should I?

Thanks.

wesgardner · Posted: Jun 27, 2004 5:58 pm Post subject:

Hey gus_jd,

No, the prop should be on the shaft good and hard. I've had to put a pipe wrench on the shaft to hold it while I loosen (or tighten) the nut. Don't forget a cotter pin....

Wes

boarditup · Addict Joined: 01 Dec 2003 Posts: 731 City: Allendale, MI

About 25 ft-lbs of torque on the prop nut. For most of us, that is a hard turn with a 3/8" socket wrench with the other hand holding the prop steady. Do not overtighten, or you will have a hard time getting the prop off. A loose prop will vibrate.

gus_jd · Outlaw Joined: 18 Aug 2003 Posts: 140 City: Milwaukee, WI

Thanks guys. I've got a torque wrench, I'll crank it down a bit.

boarditup · Addict Joined: 01 Dec 2003 Posts: 731 City: Allendale, MI

One tip. Use some spline grease or plumbers thread lock on the shaft before putting the prop on. It will make it much easier to get off in the future. Even NiBrAl and SS will corrode just a bit and bind together. The lube will make your life easier in the future.

bluefish86 · Posted: Jun 28, 2004 4:45 pm Post subject:

My boat manual says 50 ft-lbs, and you're supposed to use prop grease so that it can come off later.

wesgardner · Posted: Jun 29, 2004 4:41 am Post subject:

Oh yeah, they do make a wheel (prop) puller, most boat shops have 'em. We used to use sledge hammers with a piece of sawed off shaft to drive off props...these were large work boats, I'm not sure I'd be tryin' that on my wakeboat.... Shocked

Also make sure the key stock is good and has not been rounded over due to your prop wearing it out....

Wes

DiyGuy · Soul Rider Joined: 26 Dec 2003 Posts: 460

How critical is it that all 3 blades track exaclty in line?

We ate a fat sack pump, hose and wiring. It little to no time at all, it shreaded the hose (not easy stuff to cut, even using a sharp knife), wrapped the wire around the shaft and the pump got banged against the bottom of the boat until it was beat to pieces and fell off.

Noticed some mild vibration and cavetation during the days pulls. Back home on the trailer, one of the three blades is between 1/16 and 1/8 inch out of tracking at the tips. The edges and cups look fine though.

Should this go to the prop shop to get straighten?

Brit Rider · Posted: Jun 29, 2004 6:50 am Post subject:

is this a sterndrive or inboard/v-drive?

Sterndrives/outboards should move a tiny bit, they are on solid but should move forward/back about 2-3 mm.

V-drives and inboards should be damn tight, no movement at all.

I'd be really worried if you keep torquing that down if its an I/O.. you can do serious damage....

Please correct me if i'm wrong.. but our high 5 on the alpha leg has always moved and mercruiser say it should... same with al the props it ever had on it.

garveyj · Addict Joined: 12 Jan 2003 Posts: 877 City: Savage, MN

DiyGuy, you should get that fixed, and I suggest you also look good at the prop shaft to make sure that it is not bent. Even the slightest ding in the prop will cause performance problems. Last fall I bottomed the prop out on some gravel when taking it off the trailer, and we noticed a big vibration after that. We have since bought a new prop and have that one as a back up prop - we are going to have that one fixed at the end of the season when we have time to leave it at the shop.

wesgardner · Posted: Jun 29, 2004 8:33 am Post subject:

Hey DiyGuy,

Any vibration is TOO much, props need to be as perfect as possible...the vibration will cause undue wear to components up the drive train if it isn't corrected...

Props can be repaired...

Wes

boarditup · Addict Joined: 01 Dec 2003 Posts: 731 City: Allendale, MI

If you need a new 3-blade inboard prop - $310 shipped to your door.

rider@boarditup.com

Mr. Mutt · Posted: Jun 30, 2004 3:18 pm Post subject:

DIYGuy, I've learned it's pretty important to NOT have ANY vibration WHATSOEVER down there. We ran aground, which scuffed the prop a little but otherwise didn't cause any damage visible to the eye. Next time out there was some vibration at about 3K RPM but not below. Turns out we tweeked our strut a little. Bottom line, the mechanic told us that even a small vibration or misalignment can cause the shaft bushing to sieze, cause your strut to bend further, tweek shafts, v-drive, tranny, etc. Small vibrations are relatively cheap to fix when compared to f-ing up your v-drive or tranny.

My $0.02