V-drive dead

[mrothwell]

O7 VTX, never an issue, other than having to replace the coupler bolts on the drive shaft. Yesterday, it just stopped going into gear. It was sudden, no slipping under load. I have checked the drive shaft coupler bolts, all 4 are there and tight. I have checked the cable, even unhooked it and shifted manually, still no gear. I hear some noise when I put it in gear, but it's not horrible. The noise sounds like it's in the v-drive, not in the trans, but it's hard to tell for sure. The noise is different in forward than in reverse, so I think that the trans is engaging. I don't see the drive shaft even trying to turn. What else can I look at. Is the a shear pin in the v-drive? A key of some sort on the output connecting plate?  Help, I'm in the middle of my vacation.  I think I have enough tools to pull the v-drive unit, but not sure what to look for. 

[Ballay]

With engine off, can you turn the prop by hand? Any metal in the Vdrive gear oil?

[UWSkier]

No catastrophic noise that preceded it like a damper plate letting go makes?

[mrothwell]

Boat's in the water, so haven't tried to turn prop, but I can turn the prop by hand normally. Both trans and v-drive oil looks clean. V-drive oil is darker, because I haven't changed it as recently, but I didn't see any shavings in either, neither looks or smells burnt

 

[mrothwell]

Nothing leading up. No o noise, no slippage. 

 

I don't think it can be damper plate, because I can feel it going into gear, and forward makes a little different sound than reverse 

[UWSkier]

2 minutes ago, mrothwell said:

Boat's in the water, so haven't tried to turn prop, but I can turn the prop by hand normally. Both trans and v-drive oil looks clean. V-drive oil is darker, because I haven't changed it as recently, but I didn't see any shavings in either, neither looks or smells burnt

 

Does it make the normal gear meshing sound in reverse?  I've never tried the transmission without a load but presumably that noise from the cut of the gears will be somewhat present regardless.  Could maybe help narrow whether it's vdrive or trans.

[mrothwell]

Hard to say if that knashing in reverse is the change of sound that I hear. But that sound is why I think it's after the trans. 

[csleaver]

Every vdrive failure I have seen would make the engine stall in forward or reverse gear because the bearings were locked up.  That doesn't mean you are not having a vdrive issue, but the dampner drive plate or a transmission issue would be the first thing I would suspect.  I could be wrong, it's hard to tell from an online desciption.

[formulaben]

7 hours ago, mrothwell said:

I don't see the drive shaft even trying to turn. What else can I look at. Is the a shear pin in the v-drive? A key of some sort on the output connecting plate?

Doesn't the end of the prop shaft have a taper and key inside the flange just like the prop end?  Instead of looking at the shaft, can you look at the v-drive output flange and see if it is turning?  Fingers crossed that the locking nut is loose and you just sheared the key.

[mrothwell]

Wouldn't I see the couple turning if it were the prop shaft key? 

 

Also, if it were the damper plate, I don't think that I would hear a different sound of forward vs reverse

[formulaben]

Yes, coupler should turn, just clarifying since you said the shaft wasn't turning. 

[mrothwell]

OK. Just looked a little deaper. What holds the plate on the output shaft? Is it welded? I think that plate has busted loose. It's hard to see in there, but I'm seeing and feeling a little space in there. It's a rough feeling, and that plate is thin enough that I'm thinking it can't be taper fit with a key, like the prop shaft is. 

[UWSkier]

Do you mean the output flange on the V-drive that attaches to the shaft coupler?  Not sure on the Hurth Ski-Vee, which is what you have in a 2007.  Would be the first time I've ever heard/read of that component failing.

[Surfbinder]

On 7/31/2020 at 12:28 AM, formulaben said:

Doesn't the end of the prop shaft have a taper and key inside the flange just like the prop end?  Instead of looking at the shaft, can you look at the v-drive output flange and see if it is turning?  Fingers crossed that the locking nut is loose and you just sheared the key.

Try this; have someone start the boat, while you look from the side at the coupler that mounts to the  bottom flange of the V-drive, you will see the propeller shaft that is mounted in that coupler about 1 " diameter shaft (goes all the way through the bottom of the boat and the propeller is attached at the end of that shaft), have the person put it in gear, if that V-drive/coupler turns, but the shaft is not turning, then its what formulaben said, the 3/4 nylock nut backed off and the key has been sheared. Pretty easy to fix if it is that. 

[MakeNWaves]

Blew my drive in my 2002 vlx.  Tell tale sign was when I put the boat in forward or reverse the engine would just die.  New v-drive right before I sold it at the tune of $4000.00.

[mrothwell]

On 8/3/2020 at 10:10 PM, Surfbinder said:

Try this; have someone start the boat, while you look from the side at the coupler that mounts to the  bottom flange of the V-drive, you will see the propeller shaft that is mounted in that coupler about 1 " diameter shaft (goes all the way through the bottom of the boat and the propeller is attached at the end of that shaft), have the person put it in gear, if that V-drive/coupler turns, but the shaft is not turning, then its what formulaben said, the 3/4 nylock nut backed off and the key has been sheared. Pretty easy to fix if it is that. 

No, the coupler isn't turning.  I haven't had time to look any deeper since I got home from vacation, but I'm still leaning towards it being the output shaft flange.

[mrothwell]

Found the problem.

The coupler on the output shaft of the V-Drive broke off of the output shaft.  It's hard to see if that coupler comes off the shaft, or if it's one piece.  It looks like there is an outer ring-nut on that shaft.  The pix I took were just with my phone with it still in the boat.  Going to be hard to get to, regardless. The flange has rust in one area, and discoloration on at least a third of the ring, signifying that it has been at least partially broken for a much longer time.  I've searched all over and cant seem to find the output shaft coupler.  Anyone have any idea?

 

https://photos.app.goo.gl/ids3LrMJW4Tbscti9

https://photos.app.goo.gl/guvuwobz9GZZc26y7

 

Edited August 7, 2020 by mrothwell