Volvo sx drive stopped working while underway. No fwd or reverse

[Corian35]

Need some trouble shooting help on this.
During one of the last trips of the year I lost the starboard drive. I just got out of the marina and was on plane and going for about 10 min when the RPM gage on the starboard engine jumped and I came off plane. Tried fwd and reverse nothing. The engine rpm's increased but no moving the boat with that drive. Came back to the dock on the port engine. The boat was pulled out last week for the winter. I removed the plastic cover on the drive and had a helper move the controls. The cable was moving the mechanism but the propshaft was not engaging in either fwd or reverse. I tried moving the prop slowly to see if I could hear some sort of noise inside the lower unit but heard nothing. The prop was still in new condition so I know I didnt hit anything with it.
Any pointers on what might of caused the failure?? Upper gear box or lower gear box. Anyone have a similar issue?? If so what broke?
I will be taking the drive off this weekend and bringing it home to further inspect the insides. I did drop the gear oil and didnt notice any metal on the drain plug.
These drives are on a 1994 chris craft crowne (322) powered by 5.8L Ford
Thanks in Advance for any pointers. I will post any findings as I get into the drive.

 

[Augoose]

Re: Volvo sx drive stopped working while underway. No fwd or reverse

Rule out a shift cable adjustment/failure issue by disconnecting the cable from the shift linkage and manipulate the eccentric piston arm FULLY into forward or reverse by hand (engine off, battery terminals disconnected). Then try rotating the prop and see if it locks into gear. Let us know what the results are.

 

[Corian35]

Re: Volvo sx drive stopped working while underway. No fwd or reverse

Rule out a shift cable adjustment/failure issue by disconnecting the cable from the shift linkage and manipulate the eccentric piston arm FULLY into forward or reverse by hand (engine off, battery terminals disconnected). Then try rotating the prop and see if it locks into gear. Let us know what the results are.

Hi Augoose. Thanks for the response. I removed the formed rod from the piston arm and rotated the arm in both directions and the prop rotated freely in both directions (cw & ccw).
I went one more step and I removed the entire shift housing (making note of how the shift shoe was installed). I understand the shift shoe is suppose to move the clutch cone (up or down) to engage fwd or reverse..

 

[Augoose]

Re: Volvo sx drive stopped working while underway. No fwd or reverse

That's right....problem seems elsewhere. I think these drives may have a shear sleeve which connects the upper shaft to the lower vertical shaft- might have failed. Put the shift shoe back in and rotate the piston arm to forward or reverse - does the upper drive shaft and u-joint turn or is it locked?

 

[Corian35]

Re: Volvo sx drive stopped working while underway. No fwd or reverse

the coupler was intact.

Ok got the drive split apart today. The drive shaft in the lower gear case spins but is not connecting to the prop shaft. Need to remove the prop housing and see whats is going on at the end of the shaft. hopefully the gears are not wipped out..guessing they might be. I need to make the removal tool. will report back once I have that made and the housing removed.

 

[kelleyja]

Re: Volvo sx drive stopped working while underway. No fwd or reverse

Any chance the prop hub broke loose? That's designed to give way before the lower unit gears.

 

[Corian35]

Re: Volvo sx drive stopped working while underway. No fwd or reverse

I have the prop removed and the prop shaft turns but it does not turn the vertical drive shaft and vice versa. The only thing I can see from the drawings is the two bevel gears...I have a tooling getting made up today to allow me to remove the prop housing. I will post some pics once I have this removed.

 

[Corian35]

Re: Volvo sx drive stopped working while underway. No fwd or reverse

Got the tool finished today. Took apart the prop shaft housing, removed the prop shaft and the gear that is attached to the vertical drive shaft fell into the gear housing. removed the vetical drive shaft and it was sheared at the neck of the splined section where it gets installed into the gear. Pics attached. At least its not boating season and I have a few months to find the parts and fix everything.

Guess the previous owner forgot to tell me he might of hit something. LOL. At least it broke at the end of the season. Thanks for everyones input.