VP 290 DP reverse issue

[welshswampy]

Had my boat out for annual service/clean etc, and had a small amount of water in the outdrive oil, did the suggested compression and vacuum checks and it turned out to be a bad "o" ring on the drain plug, so I thought I had dodged a bullet.Dropped her back in this afternoon and went for a spin around the bay everything was fine until we got back to my mooring, steered in as normal and went to grab reverse on full lock to bring the stern in and had next to no reverse, was fine selecting forward all good and smooth, but when reverse was selected the drive felt like it was only partially in gear and slipping.I very loosely moored up and spent a few minutes just selecting forward and reverse, no clunking in forward but got a bit of a clunk when going from reverse to neutral, not a horrible sound just felt it through the boat AFTER selecting neutral whilst coming out of reverse.I didn't have time today for much of an investigation other than to check the linkage behind the cover on the outdrive. I am hoping that the reverse lock mechanism wasn't engaging and the drive was kicking up and the noise I heard was it falling back down, any other ideas? as I say forward was absolutely fine

 

[RicardoMarine]

Questions:
Are you not getting Reverse Propulsion due the drive kicking up?
Or are you not seeing the sliding sleeve making full lock-up while reversing?


The 290 latch unit is different from the 250, 270, 275, 280, 285 drives.
With the 290 drive, it's primary function is for impact break-a-way.
There is no release rod for disengaging the latch, nor will you see the anti-rotation pins.

However, it still relies on the center lift spring to keep the latch hooks against the equivalent of the earlier "set pin".
Check this spring to make sure that it's still in tact and working.

Next.... I'd pull the shift mechanism, and take a look inside. Make sure that the shift shoe is OK.

It will cost you 1 OEM shift mech housing O-ring, 1 drain plug and 1 dip stick O-ring only.




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[welshswampy]

I didn't think about the latch spring/mechanism until the drive home so this wasn't checked yesterday, I just assumed the worse whilst I was on the boat, I was getting partial drive in reverse but not enough to stop the boat (this, as you say, maybe due to the drive kicking up and the noise I heard was it dropping back down) I will be going down to check when the weather clears and work allows and will post back, can there be a fault with the clutch just in reverse?

 

[RicardoMarine]

can there be a fault with the clutch just in reverse?

Typically not.
Not unless for some reason the sliding sleeve is not being moved far enough into the REV driven gear cup.
We need contact friction in order for the two to lock up.


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[RicardoMarine]

Here's a rather simple explanation that may help you understand how the sliding sleeve and gears cups work.

Gear engagement is accomplished when friction between the conical surface of the sliding sleeve and conical surface of either gear cup occurs.
The steep spiral cut splines cause the sleeve to further pull itself into the gear cup, until eventual "lock-up" is achieved.
Once locked-up, and during continued load, the two will not separate until the load is reduced.


Debris within the oiling grooves on the conical sleeve surface may cause a sleeve to not lock-up, or may cause a sleeve to let go under heavy power, or it may cause a sleeve to become stuck in the gear cup.
The fix will be to disassemble the transmission, and take a good look.
The oiling grooves can be gently cleaned out.
If the sliding sleeve is bronze, these surfaces can be mildly lapped into the corresponding gear cups.

 

[welshswampy]

Had someone stand at the stern whilst I engaged reverse and the drive does kick up, so trimmed drive up fully and lowered fully a few times and no difference, still kicking up
Ordered a set of springs today, so hopefully I'll be able to see the problem when she comes back out
Does the boat have to be completely removed to get at these springs, or can I trim drive up fully in shallow water to work on/replace them........ and would I need a snorkel

 

[RicardoMarine]

Does the boat have to be completely removed to get at these springs, or can I trim drive up fully in shallow water to work on/replace them........ and would I need a snorkel

This will be so much easier if the boat was pulled out of the water.
You can kill a few other birds at the same time.

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[welshswampy]

Took the boat from my mooring to the slip and donned a dry suit(which didn't really fit) waded in and after letting the water clear, could see that the whole reverse latch mechanism had spun about 10 degrees or so, causing it to catch on the trim ram bolt instead of locating on to the bar
Moved it back to centre an everything is fine
Should this be able to be moved by hand? it isn't loose but can be moved

 

[RicardoMarine]

Took the boat from my mooring to the slip and donned a dry suit(which didn't really fit) waded in and after letting the water clear, could see that the whole reverse latch mechanism had spun about 10 degrees or so, causing it to catch on the trim ram bolt instead of locating on to the bar
Moved it back to centre an everything is fine
Should this be able to be moved by hand? it isn't loose but can be moved

The 290 drive reverse unit has omitted the anti-rotation pins (as with the earlier drives), in lieu of a metal tang affair.
These can become bent or distorted.

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