Prop Contacts Trim Tab Only When In Gear Not Neutral

[GTWarrior]

Hey guys I just recently installed my new prop and took my boat out on the water. Everything was fine until a few hours in I hear my Propeller hitting my trim tab. This only happens in Forwards and Reverse not in neutral. I do not know what is causing the prop to shift upwards when in gear. If anyone has any idea I would appreciate the help. Thank You!

 

[Bt Doctur]

Everything was fine until a few hours in I hear my Propeller hitting my trim tab. This only happens in Forwards and Reverse not in neutral.

Something got loose, in neutral the prop doesnt spin

 

[Scott06]

Hey guys I just recently installed my new prop and took my boat out on the water. Everything was fine until a few hours in I hear my Propeller hitting my trim tab. This only happens in Forwards and Reverse not in neutral. I do not know what is causing the prop to shift upwards when in gear. If anyone has any idea I would appreciate the help. Thank You!

Check everything is still tight. Not uncommon to have to trim the trim tab with different props nothing a grinder can clearance.

 

[GTWarrior]

Everything was fine until a few hours in I hear my Propeller hitting my trim tab. This only happens in Forwards and Reverse not in neutral.

Something got loose, in neutral the prop doesnt spin

Sorry to clarify my prop does not spin in neutral. I meant if I spin it by hand it clears the trim tab. But if I put it into to gear even without the boat running and try to spin it, the prop hits the trim tab

 

[GTWarrior]

Check everything is still tight. Not uncommon to have to trim the trim tab with different props nothing a grinder can clearance.

Check everything is still tight. Not uncommon to have to trim the trim tab

My question is Why would it only happen in gear and not neutral. Does that mean something is wrong internally?

 

[Scott06]

My question is Why would it only happen in gear and not neutral. Does that mean something is wrong internally?

There is normal fore/aft play in shaft that I think gets taken up when it locks in gear. Remove prop lock in gear and see what happens

I think it’s normal just need to check clearance when changing props

 

[GTWarrior]

There is normal fore/aft play in shaft that I think gets taken up when it locks in gear. Remove prop lock in gear and see what happens

I think it’s normal just need to check clearance when changing props

Prop Lock? Sorry but is that the locking washer for the prop?

 

[Rick Stephens]

Carve a hunk off the tab before you break something.

 

[Scott06]

Prop Lock? Sorry but is that the locking washer for the prop?

Remove the prop, then lock drive in gear

 

[dingbat]

What prop and drive?
Pretty common for prop changes to require a change of the thrust washer as well

 

[ROY WILLIAMS]

Prop Lock? Sorry but is that the locking washer for the prop?

did you look up the old prop and the new prop ...bushing is a different new prop bushing or other prop lock ups nut etc..

 

[tank1949]

Hey guys I just recently installed my new prop and took my boat out on the water. Everything was fine until a few hours in I hear my Propeller hitting my trim tab. This only happens in Forwards and Reverse not in neutral. I do not know what is causing the prop to shift upwards when in gear. If anyone has any idea I would appreciate the help. Thank You!

maybe transom is rotten and flexing?

 

[GTWarrior]

What prop and drive?
Pretty common for prop changes to require a change of the thrust washer as well

Hey, it's a Mercury Alpha One Drive and I will add a picture of the prop I'm using.

 

[dingbat]

Hey, it's a Mercury Alpha One Drive and I will add a picture of the prop I'm using.

Should be using this washer with the Flo-torque hub.

Mercury-Mercruiser 12-8354671 THRUST WASHER

Mercury-Mercruiser 12-8354671 THRUST WASHER genuine factory part not aftermarket. Fast shipping - Click here to see live inventory status

www.mercruiserparts.com

Make sure you torque the prop nut to 55 ft. Ibs. Required to fully set the flo-torque insert in the prop.

 

[ROY WILLIAMS]

Hey, it's a Mercury Alpha One Drive and I will add a picture of the prop I'm using.

the trim tap is different ..post the picture ...

 

[GTWarrior]

Should be using this washer with the Flo-torque hub.

Mercury-Mercruiser 12-8354671 THRUST WASHER

Mercury-Mercruiser 12-8354671 THRUST WASHER genuine factory part not aftermarket. Fast shipping - Click here to see live inventory status

www.mercruiserparts.com

Make sure you torque the prop nut to 55 ft. Ibs. Required to fully set the flo-torque insert in the prop.

Hey, would this work also?

Quicksilver 835257Q1 Flo-Torq II Hub Kit - for Mercury/Mariner and MerCruiser Engines https://a.co/d/gqaGXDQ

 

[dingbat]

Hey, would this work also?

Quicksilver 835257Q1 Flo-Torq II Hub Kit - for Mercury/Mariner and MerCruiser Engines https://a.co/d/gqaGXDQ

No…. Says right on the prop box you posted - Quicksilver 835257K1 Flo-Torq II Hub

 

[Scott06]

No…. Says right on the prop box you posted - Quicksilver 835257K1 Flo-Torq II Hub

Pretty sure the Q1 part is the quicksilver version of the mercury K1 version. Merc and quicksilver use basically the same part number except for a digit or character. Same part sold through merc dealers or labeled as quciksilver anywhere …. Both require the correct thrust washer i suspect that the OP has a gen one drive i dont think the gen 2 has a steering tab…. Possible it was set up with pressed hubs originally

 

[GTWarrior]

Pretty sure the Q1 part is the quicksilver version of the mercury K1 version. Merc and quicksilver use basically the same part number except for a digit or character. Same part sold through merc dealers or labeled as quciksilver anywhere …. Both require the correct thrust washer i suspect that the OP has a gen one drive i dont think the gen 2 has a steering tab…. Possible it was set up with pressed hubs originally

So that hub kit with the thrust washer I linked should work then?

 

[dingbat]

Pretty sure the Q1 part is the quicksilver version of the mercury K1 version. Merc and quicksilver use basically the same part number except for a digit or character. Same part sold through merc dealers or labeled as quciksilver anywhere ….

Not a merc guy….so not familiar with part numbers other than those noted on the box

Both require the correct thrust washer i suspect that the OP has a gen one drive i dont think the gen 2 has a steering tab…. Possible it was set up with pressed hubs original

Shouldn’t matter. Kit comes with appropriate thrust washer