Another prop slipping thread

[beech2000]

What do the splines inside the coupler look like?

Splines seem to look great.

 

[alldodge]

I would say it must be the coupler has stripped. Would feel better if you smelled burnt rubber after it happened

Don't think the BB coupler will fit, but never tried. They do make a steel coupler but all that means is the splines are steel instead of aluminum. Both use molded rubber to attach

 

[ROY WILLIAMS]

Splines seem to look great.

THE U JOINTS ARE RUSTED ...IN THE BELLOWS IN THE WATER .
THE DRIVE SHAFT IS NO WATER IN THE SPLINES NO RUST ..

 

[beech2000]

water over damn... With OD installed, and with a buddy and a vice grip, stop motor from turning (best way) while you attempt to move prop with a 2x4" If anything moves, pull prop and take to shop and pray it needs repairs and not coupler. I had similar problem with a MC/Proline

Would love to find a way of doing a similur test with the coupler out and on the bench

 

[beech2000]

I would say it must be the coupler has stripped. Would feel better if you smelled burnt rubber after it happened

Don't think the BB coupler will fit, but never tried. They do make a steel coupler but all that means is the splines are steel instead of aluminum. Both use molded rubber to attach

Me too but no burnt rubber odor that I can recall. I could however weld the shaft to the outer dome. Couplers sure are pricey and offer no integrity

 

[QBhoy]

You might benefit from Rhoda lifters very commonly used in us to tame wild camshafts by bleeding off duration at low
Rpms

Just noticed this reply. Apologies for not responding. Tell me more !!

 

[alldodge]

Me too but no burnt rubber odor that I can recall. I could however weld the shaft to the outer dome. Couplers sure are pricey and offer no integrity

Don't know about coupler integrity, but I've never had one fail if it was checked yearly. Didn't matter if it was a 4 cyl or up to a 530 HP BBC

Did have one burn up in my early years when I didn't check yearly

Post a want to buy in the Offshore only section.

 

[Scott06]

Just noticed this reply. Apologies for not responding. Tell me more !!

Rhoads lifters bleed off cam duration at low rpms To tame wild cams And create more low end power and idle vacuum. They reduce the effective cam duration by 10-15 degrees below 3500 rpm. Commonly used in hot rods in the US. Probably the first attempt at variable valve timing, but rather than advancing or retarding the cam it bleeds off lift and duration.

Original Flat Tappets

 

[beech2000]

I would say it must be the coupler has stripped. Would feel better if you smelled burnt rubber after it happened

Don't think the BB coupler will fit, but never tried. They do make a steel coupler but all that means is the splines are steel instead of aluminum. Both use molded rubber to attach

Well,
I've officially eliminated any and all sources. No other option than to order a new coupler. I am going to order up a new input shaft bearing though as the one shown in picture and still on shaft is scored and worn. Thanks for your help.
Oh BTW should I go with OEM? coupler? any after market version that seem to be equal in quality?

 

[QBhoy]

Rhoads lifters bleed off cam duration at low rpms To tame wild cams And create more low end power and idle vacuum. They reduce the effective cam duration by 10-15 degrees below 3500 rpm. Commonly used in hot rods in the US. Probably the first attempt at variable valve timing, but rather than advancing or retarding the cam it bleeds off lift and duration.

Original Flat Tappets

Excellent. Thanks so much for that. I’ll get a look tonight !!

 

[alldodge]

Never tried aftermarket but others have and have not heard of problems

 

[Scott06]

Well,
I've officially eliminated any and all sources. No other option than to order a new coupler. I am going to order up a new input shaft bearing though as the one shown in picture and still on shaft is scored and worn. Thanks for your help.
Oh BTW should I go with OEM? coupler? any after market version that seem to be equal in quality?

I usually go oem. While they are expensive there is too much junk out there

last Sierra item i used , trim sender, never worked right . Limit switch works, could never get the sender working right seems to be reasonably accurate at idle speed but goes all the way up when on plane. Too much pita to redo.

 

[ROY WILLIAMS]

Well,
I've officially eliminated any and all sources. No other option than to order a new coupler. I am going to order up a new input shaft bearing though as the one shown in picture and still on shaft is scored and worn. Thanks for your help.
Oh BTW should I go with OEM? coupler? any after market version that seem to be equal in quality?

the outdrive bellows of the inside it full the water . u joints / bearings and did the bearing / shafts you was the gear oil in the fall ! the gear oil is the lower port hole ..did the gear oil inspected it ..

 

[beech2000]

I usually go oem. While they are expensive there is too much junk out there

last Sierra item i used , trim sender, never worked right . Limit switch works, could never get the sender working right seems to be reasonably accurate at idle speed but goes all the way up when on plane. Too much pita to redo.

I had a brain storm.
A loaded down boat that day with a 21 pitch prop and tons of horse power..... I'm thinking.... since nothing found I'm the culprit of extreme prop cavitation. I understand the level of stupidity but that's the only explanation as no smoking gun identified.
Following the event we opened the hatch and no smoke in the engine compartment from the coupler noted. Once boat was on trailer No mechanical failure of any sort in the out drive and prop can't spin due to flow torque designed hub.
Since I have the upper and lower torn down I'm replacing the bearings, resealing the drive, new water pump and putting her back together. Thoughts?

 

[Scott06]

I had a brain storm.
A loaded down boat that day with a 21 pitch prop and tons of horse power..... I'm thinking.... since nothing found I'm the culprit of extreme prop cavitation. I understand the level of stupidity but that's the only explanation as no smoking gun identified.
Following the event we opened the hatch and no smoke in the engine compartment from the coupler noted. Once boat was on trailer No mechanical failure of any sort in the out drive and prop can't spin due to flow torque designed hub.
Since I have the upper and lower torn down I'm replacing the bearings, resealing the drive, new water pump and putting her back together. Thoughts?

Yes completely agree was thinking about this wondering if the prop to hub clearance or slip is greater. I would not not replace the coupler since you are there and the alpha drive either grabs or it doesn’t. You may need a prop with more bite if you go out with a boat load of people…

try a prop like revolution 4 or enertia that has grip See if you have same results