I would not characterize the noise I have have has “backlash”….. more like a machine gun going off until I increase the RPM…… ???
alan

— On Wed, 12/15/10, John Stevenson wrote:

Post generated from Pearson424 Forum using Mail2Forum

John,

I have the exact same engine and transmission…..no backlash at 750 rpm…so I
don’t know why you would be getting any.

Joe
Half Moon #71

________________________________

Post generated from Pearson424 Forum using Mail2Forum

     Type of Engine   Westerbekre W58
   – Type of Transmission and gear ratio  Velvet Drive 2:1 I think
   – V-Drive model RV20
   – RPMs at idle 700
   – Gear Backlash Level: LOUD
      – None
      – Slight
      – Loud

— On Wed, 12/15/10, John Stevenson wrote:

Post generated from Pearson424 Forum using Mail2Forum

I put a new damper plate on…. Westerbeke Original part (with springs) AND had the VDrive rebuilt…. so I am not entirely positive WHAT is generating the noise except that is it coming from the VDrive.

Type of Engine   Westerbekre W58
   – Type of Transmission and gear ratio  Velvet Drive 2:1 I think
   – V-Drive model RV20
   – RPMs at idle 700
   – Gear Backlash Level: LOUD

— On Wed, 12/15/10, John Stevenson wrote:

Post generated from Pearson424 Forum using Mail2Forum

I may remove the VDrive and drive it Walters to have it bench tested (in my presence) while the boat is on the hard.
Alan

— On Wed, 12/15/10, John Stevenson wrote:

Post generated from Pearson424 Forum using Mail2Forum

I hear ya…. after spending last winter in the Carib…… I am back in Rochester where we’ve gotten over 44 inches of snow so far in just December…..
Don Walter is pretty sure the VDrive OK also but is willing to put it on the test bench just to make sure…. and to please me……
I wonder if the noise will go away or lessen after the damper plate has a few miles on it?
Alan

— On Wed, 12/15/10, John Stevenson wrote:

Post generated from Pearson424 Forum using Mail2Forum

Type of Engine Westerbeke W58
– Type of Transmission and gear ratio Velvet Drive 1:1
– V-Drive model RV20 2:1
– RPMs at idle 800
– Gear Backlash Level: moderate but smooths out at 1,000 rpm
Westerbeke damper plate
We replaced damper and rebuilt both trans and v-drive when we got Clairebuoyant. Two damper plate springs were in the bottom of the bellhousing when we got her.
It would also be interesting to know how much play there is in the v-drive between input and output shafts, and what prop and stuffing box is used. We do have a bit of play probably from the u joints in the input shaft housing.
At low speed the diesel might be a bit rough, but there would also be less drag on the v-drive output shaft. Things would bang around a bit more in the v-drive.
The VD is a strong transmission. It should handle a lot more power than these small diesels produce.
Is it possible something in the VD broke off and jammed up the works?
Quent

Engine: Westerbeke W60
Transmission: Paragon
V-Drive: RV-20
Idle RPMS: 800
Gear Backlash: Imperceptable

Prop: Max Prop feathering

Chewed up gears, not clutch plates? I could be wrong about VD, but in the marine transmissions I’ve seen the gears were always engaged, and the clutch packs got squeezed together to engage the output shaft. I would think that ripping teeth off the gears would take a lot of force, like maybe jamming a log in the prop. Something that you would notice.
Q

John,

Please define “gear backlash.”

Tor

Post generated from Pearson424 Forum using Mail2Forum

Oh, THAT noise. Yes, I’ve go it, too, though I don’t know how far from the
boat it’s audible.

– Type of Engine Yanmar 4JH4E, fairly new
– Type of Transmission and gear ratio Paragon, Serial No. 32865,
original, rebuilt 400 hrs ago
– V-Drive model Original, serviced 400 hrs ago
– RPMs at idle Around 750, I guess
– Gear Backlash Level: Pretty loud in the cockpit and
annoying to the captain
– None
– Slight
– Loud

Tor

Post generated from Pearson424 Forum using Mail2Forum

John,

On Doris E. I would call it very slight:

Type of Engine Westerbeke W58
– Type of Transmission and gear ratio Velvet Drive 1:1
– V-Drive model RV20 2:1
– RPMs at idle 800
– Gear Backlash Level: slight
Westerbeke damper plate

~3200 hrs. on all drive components. Max prop for the last ten years.

Dave

On 12/15/10 7:40 PM, SilverHeels wrote:

John (or anyone else),

Let us know if you derive any useful “gear backlash” conclusions from our
responses to your engine / drive train info request.

Thanks,

Tor

Post generated from Pearson424 Forum using Mail2Forum

John,
If I were a betting man ( and I’m not ), I would bet the loose springs on your
damper plate is found guilty.

Joe,

________________________________

Post generated from Pearson424 Forum using Mail2Forum

John,
Interesting read. I don’t remember hearing any backlash with my old w60
installation. I operated it for over 20 years, but the engine was so noisy
that I may not have noticed. I repowerd about 4 years ago with a 75hp
yanmar (4jh3te), an engine similar to yours. I’m pretty sure I had the same
damper plate as your origninal. At that time I rebuilt the velvet-drive and
replace the v-drive. Both the old RV-20 and the new RV-26 make a racket
when in gear. With the cabin sole hatches in place its not that bad, but
the V-drive makes more noise than the engine until I get it up to speed. At
about 6kts, the engine is very quiet and smooth. At idle in gear, there may
be some noise from the v-drive. I think the gears rattle around in the
V-drive, but its not that bad. I almost never run the engine that slow in
gear. I don’t see the point unless I’m waiting for a bridge and need to
compensate for a light wind or current. This is pretty rare for me. I
never shift gears without pausing in neutral and letting the engine idle.

About once every couple of weeks I run my boat hard, full throttle for about
20 minutes. This is SOP for this engine. This kicks up quite a stern wave
and makes the boat squat. It will run almost halfway up the transom. Even
with this kind of abuse, I’ve had no issues with the v-drive, transmission,
or damper plate in spite of this abuse. I don’t motor all that much
however, maybe 150 hrs each year.

Rich

I wonder if it has anything to do with the type of lubricant you use. I put
SAE-30 in the gearbox and addes some kind of additive as recommeded in the
installation instructions. I change the gear lub each season, but omit the
additive.

Rich

I use standard ATF transmission oil..so I doubt that viscosity is the solution.

________________________________

Post generated from Pearson424 Forum using Mail2Forum

Having discussed this some time ago with the people at Walter, the backlash
we are hearing at low speed is from the power pulses from the engine being
absorbed through the gearset. Walter says it’s expected, it’s noisy, and it
doesn’t hurt the v-drive. The reason it goes away at higher rpms is because
the power pulses smooth out.

The transmission, especially the Velvet Drive is hydraulic and couldn’t care
less about power pulses. I’m not sure the failure is due to the damper
plate or the backlash. Upon being torn down, I’d want to know what,
exactly, failed.

Having broken or weak springs on the damper don’t help the issue because the
pulses are not absorbed at higher than normal rpm. They are basically small
shock absorbers.

I’ve had 80 wt oil in the v-drive. Makes it very quiet. Also wrong. 30 wt
oil works fine but the gear whine is quite audible. At very low rpms, it
sounds like it’s pumping marbles but that’s the backlash I expect. I try
not to run it long at those speeds.

The transmission currently has ATF in it but will run with, wait for it…
30 wt oil, according to the manual. I could, in theory, run the whole kit
and kaboodle with 30 wt. It’s tempting.

No matter what you do, when you reach the point where the power is not
smoothed out by the damper, flywheel, and damper plate, you’ll hear the
v-drive banging around.

Bob

On Fri, Dec 17, 2010 at 8:31 AM, Joseph Steiner wrote:

Here is the VD manual. I think we all have model 71c, no reduction.
http://www.marinepartsexpress.com/bw_sch_fs.html

The VD shifts by hydraulic pressure, but power is transmitted directly through a gearset. There would be no damping of power pulses in the transmission unless the transmission clutches were slipping, which would be a bad thing.
Quent

John, backlash is a measurement between gear teeth. If the backlash is excessive it means the gears are not mating each other at the proper area on the tooth face. This normally does not result in more noise in one direction or other but may when changing direction as there’s more play in the gears before they engage.

This is a good reference for how it is measured. http://www.clevelandgear.com/hg/backlash.htm

The Velvet Drive is a hydraulically operated gear, hydraulic pressure moves the clutch plates to engage the drive gear. Once the gear is engaged it is a solid coupling. Worn clutch plates, clogged pump passages among other things will result along with a myriad of other issues can prevent the gear from going into reverse.

The V-Drive is a noisy component and has nothing to do with forward/reverse. It transfers power output from the gear to the prop, regardless of direction.
The RV-26 is not a bolt in replacement for an RV-20. It has a different mounting profile that requires appropriate spacing.

If you lost reverse it was a failure of the transmission, not the V-Drive.

Consider this, the entire forward thrust of the boat is being created by the spinning prop. This is transferred forward up the shaft, through the gearing into the bearings in the V-drive and into the mounts that hold the V-Drive in place, this is where the entire load moving the boat is finds its way to the fiberglass. As thrust loads increase it forces the gears closer together, compresses and twists the shaft, stresses the V-drive mounts.
The mounts are rigid, so any deformity of the shaft, unbalanced or bent prop will be transmitted to the hull. The V-drive essentially becomes a thrust bearing. A true thrust bearing has flexible mounts.

You can search for the reason of failure but your funds would be better spent on insuring all engine and drive train components are properly installed, aligned, lubricated and cooled.
Damper plates should be replaced anytime the gear is off, and Yanmar does update and improve parts continuously.

I watch owners (myself included) sometimes try to diagnose and correct issues, thinking there’s going to be a ‘single issue’. Often it is a combination of things that occurred that made us aware there is a problem. Methodical, effective troubleshooting is often seen as expensive but more often than not fixes the problem.

I wish you the best in isolating this issue on your own. Working in a yard and being a boat owner I see both sides. I know mechanics are expensive but getting it all right can be worth it. Even better, getting a yard that says if it isn’t, bring it back and we’ll make it right is even better. Where I work that is our policy.

Chuck

John, this is great news. In reverse remember that the shaft is now ‘pulling’ at the V-Drive so it is very possible it may sound different. I’ve never paid that much attention to the sound the thing makes other than noting that it’s a noisy contraption. I doubt I’ll buy another boat anytime soon. If I do it won’t have a remote mounted V-Drive. The complexity and aggravation it add isn’t really worth the space it saves. This is especially noticeable when you have to change out an alternator belt on a hot engine.

Chuck

John,
   I wish I knew whether the damper plate I replaced is faulty or the V-Drive is at fault and whether it really IS OK as Walter’s says….. Changing out that damper plate is not that easy……
Alan

— On Wed, 1/5/11, Chuck Ruble wrote:

Post generated from Pearson424 Forum using Mail2Forum

When I removed the old damper plate, 2 of the springs were lying at the bottom of the bell housing and the others were about to fall out. I replaced it with a genuine Westerbeke part.
So I guess this is what it sounds like with a tight damper plate.
 I am sure it didn’t sound like this with all new parts back in 1981!

— On Wed, 1/5/11, John Stevenson wrote:

Post generated from Pearson424 Forum using Mail2Forum