Is it my tranny or my prop

[Raquin]

I just bought a 39 ericson. It has a feathering prop on it. I know it is a long shot but I am hoping it is the prop slipping and not the tranny. When I get the rpms up about 35 percent it gives way and rpms increase and there is slippage. I have to slow the rpms to get it to reengage. I checked the tranny fluid and it is red and at the perfect level. I am at a loss. Is there maintenance to this prop and could that cause it to slip or just not feather. The boat I believe was sitting for at least a couple of years. It has a velvet drive tranny. Thanks for your input.

[lancelot9898]

I also have a feathering prop(max prop) and the velvet drive tranny on the Perkins 4-108. Having taken that max prop apart for more years than I like to think about, I really doubt the problem is in the prop since you mention that you can reengage it by slowing the rpm. If it was the prop that was missing and or had worn gear teeth, I would not think it would reengage. My 2 cents.

[Tim R.]

Forget about what the tranny oil looks like. Drain it and re-fill with the correct fluid. Just because it is red does not mean it is not contaminated. Also, you cannot be sure you have the right fluid if you did not fill it yourself. This should be your first step troubleshooting as it is easy and cheap to do.

Sorry, but I doubt it is the prop. They typically feather or not and do not show symptoms of slippage at higher RPM.

Yes, deferred maintenance of some feathering props will cause them not to feather properly. What model prop do you have?

[shorebird]

Among other possible causes, significant marine growth on the prop can cause it to cavitate at certain rpms. Ask me how I know...

[Raquin]

The first thing I did was clean the prop, there was barnacles on it. The blades seam to feather back and forth easily. I guess that is how it works. I will drain the tranny and make sure I have the right fluid in it. All input welcome thanks.

[Bowman Sailor]

Raquin,

It sounds like your clutches are slipping. If you have a Hurth HBW 125 or HBW 150, (or ZF 12 or ZF 15), transmission, try loosening the four bolts that connect the shifter mechanism to the starboard side of the gearbox and shifting them forward or aft slightly and then re tighten the bolts. This might cure an adjustment problem. If not, these transmissions can be bought from Transatlantic Diesel in White Marsh, VA for about $1,500. You can put it in yourself. I wouldn't buy a rebuilt unit, since the new ones are so cheap.

Of course, try the fluid change first. The above mentioned transmissions take about 3/4 of a quart of ATF.

Good luck,

Steve

[highseas]

Sounds like burnt/worn clutches.Alot of people use motor oil instead these days,seems to work better.I still use ATF though.

[Bowman Sailor]

By the way, congratulations on your new boat. A friend of mine owns a sistership and he loves it.

Fair winds,

Steve

[SkiprJohn]

Congratulations on the boat! Let us know how the troubleshooting on the transmission goes.
kind regards,

[Raquin]

Bowman sailor, If our paths cross I owe you a few cold ones. It turns out it is a linkage problem. You are the man. I think the plates might be near the end of there life but for today I will sail. THANK YOU. What a load off.

[Bowman Sailor]

Raquin,

Glad I could help. I hope you get a few more pain free years out of your transmission. BTW, I would love to split a twelve pack with you some time. Let me know if you are ever in the southern Chesapeake.

Cheers,

Steve

[SkiprJohn]

Well done Bowman!

Glad it was an easy fix. Isn't it great when things are an easy fix!

kind regards,