Damper Plate Rattle

[Witzend]

This is also posted on the C310 Fourm.
Well folks, I pulled the engine and split the bell housing to find out why I was getting so much rattle from 1000-1500RPM. What a job!
I was literarily revolutions away from completely striping out the spline collar on the damper plate due to the P.O. installing the incorrect one (see Pics). The tranny is not original because there is no name plate on it. I believe I have identified it by dimension and input to output ratios as a Hurth ZF 5 or 6. Unfortunately because the wrong damper plate was used (the collar is way too large in Dia, this caused a very loose fit, can't believe this was installed like this!! The trannys input shaft splines leading edges are quite worn and as a result the entire shaft will need to be replaced. The tranny does not leak, no appreciable play, and the fluid was clean. So what to do, get the shaft ~$400 and replace it, or get a new tranny ~1200? I will also be replacing the motor mounts and cutlass bearing. Has anyone replaced the motor mounts, if so where did you get them and which ones did you use? I will need to maintain the lateral adjustment feature (the wide mounting slots) the engine needs to be offset quit significantly to the starboard in order to get my alignment correct.

 

[kloudie1]

Looks like ya caught it just in time!.. I'd tend to go the replacement shaft route but before making the decision, I'd inspect the transmission innards.. If everything looks good.. bearing fits and the engaging cones, then I'd get a new shaft and replace the old one and the damping disk.. Remember to clean the insides as if it were your operating room when it goes back together..

 

[Steve Dion]

What motor do you have?

 

[Witzend]

M25XP with only 525hrs on it.
I may have come up with a innovative way to solve the problem of the worn spline without changing out the shaft. The spline is only worn near the outer length. If I slide the new damper plate (that I already purchased, Sachs #1866--50-002) further into the shaft, it is tight because there is no wear there. The old damper is 6" OD, thus the existing mounting ring will not receive the correct damper plate anyway, which is 4.75" OD. If I manufacture a second mounting ring from SS that is ~5/8 thick and 6.5" OD and ~4" ID with the proper holes, I can mount this ring on the existing ring. This will push the new damper plate further into the spline where there is no wear. I need to calculate the thickness of the ring very carefully so I don't bottom out the plate and create inward thrust in the input shaft. The biggest concern is making sure when the plate is spinning, it is not wobbling and the center of the plate lines up with the center on the input spline shaft of the tyranny. I have a deflection gauge to measure the wobble, but the centering will have to be done by fit. This is a concern anytime you replace the damper plate and I realize that by adding a second mounting ring it increases the chances of run out.

Come on, anyone ever change their motor mounts on this engine? Pipe in here, which ones did you use, why, and where did you get them?

 

[Maine Sail]

The old damper is 6" OD, thus the existing mounting ring will not receive the correct damper plate anyway, which is 4.75" OD.

Witz,

Am I understanding correctly that the hole pattern on the flywheel will not accept your "new" supposedly correct damper plate?

The fly wheel is most likely stock, factory original, and what ever damper plate you purchased should match up to this fly wheel. With 525 hours I find it unlikely that the flywheel was replaced, but you never know? If the damper plate part number you ordered is for an M-25 not an M-25XP (A,B,C) it may be the wrong one?

Come on, anyone ever change their motor mounts on this engine? Pipe in here, which ones did you use, why, and where did you get them?

Personally I always use Westerbke/Universal or Yanmar stock mounts. Done it both ways and will no longer use the aftermarket stuff. Damping characteristics, size, shape, hole centers etc. etc. can all make after market mounts a royal PITA. I actually helped a friend convert back to factory mounts on his Yanmar after installing some "fancy" aftermarket stuff that made his boat feel like a Vegas vibrating bed, just without the quarters...

A good place to check on mounts is the C-34 site as I know some guys there have converted to aftermarket.

 

[Stu Jackson]

Come on, anyone ever change their motor mounts on this engine? Pipe in here, which ones did you use, why, and where did you get them?

Our C34 skippers recommend Vetus K50 or K75 mounts, sometimes a mix of the two. The K50s are said to be soft, so K75 on the rear are the mix pattern. Do a search on our C34MB and the wiki on engines.

http://c34.org/bbs/index.php/board,11.0.html

http://www.c34.org/wiki/index.php?title=Main_Page

We and the C36 folks do a lot about M25 series engines.

 

[paulj]

WitzEnd

Need to see those pictures of your conversion.

I'm still undesided on which motor mounts I will use.........OEM or after market.

Thanks for leading the way on this one.


paulj :troll:

 

[Witzend]

Maine,
I was hoping you would pipe in here. It is not just the hole pattern, the diameters are different as well. There is a ring that is bolted on the flywheel that this damper bolts to. The damper was made by R&D, 22B4 is the number on it and is not a spring damper but has a polyethylene ribbon. I had Jim at Federal Marine look it up and it does not have the correct Ft Lbs. rating for my engine, way too stiff. The Sachs one I bought 1866-50-002 is the correct one and is a direct cross to the factory number, according to him. Please, correct this information if I'm being mislead.

Stu, K mounts do not provide enough lateral movement to correct my alignment issues. I will probably go with the factory mounts, Jim wants $169/per ouch.
Any other sources or ideas would be much appreciated.

I have the engineering drawing almost completed for my adapter ring. I have a good relationship with a local shop that should be able to cut me one for a good price, we will see. Remember this adapter ring is solving (2) problems, the diameter/hole pattern and positions the damper receiving collar further into the spline shaft where there is no wear.

 

[Maine Sail]

. The damper was made by R&D, 22B4 is the number on it and is not a spring damper but has a polyethylene ribbon.

Most of the factory dampers are made by Sachs but I don't know any way to cross reference the Sachs # to OEM unless you have an OEM Sachs sitting there to look at.

The Damper plate I pulled out of my boat was a Sachs 10-1866-061-001 and the replacement damper plate I used was a Sachs 10-1866-061-001 works well..

 

[Witzend]

That was on your C310 with the M25XP?

 

[Witzend]

http://www.merequipment.com/22617/228559/Transmission-Drive-Plates/80100-Sachs-Drive-Plate.html

This one?

 

[Maine Sail]

That was on your C310 with the M25XP?

Sorry not clear that was on my Westerbeke.. I never had to replace a damper plate on either of the two M-25's I owned..

 

[Maine Sail]

Witz,

I just made a call to the distributor who ships the engines to Catalina and whom I get my Universal/Westerbeke parts through.

The R&D damper plate was stock, and factory, however according to the distributor "We had nothing but problems with them and most of them failed and some caused more damage than good"

I never knew Universal used anything but Sachs but apparently they did try some R&D's...

The spline fit was most likely spot on but as it failed it began to eat at the splines. The replacement Universal/Sachs damper plate is a Universal part number U-299156. I had them pull it off the shelf and read me the part numbers. The Sachs number is a 1866-050-002.

You can buy one here for $70.78

 

[Witzend]

What was the HP and what RPM did it develop it at on your Westerbeke? If you remember the model # I can probably find it.

 

[Witzend]

Sorry, I did not see your latest post. Yea, that's the part I bought, I will now have the need to manufacture the adapter ring to get it to fit. Thanks sooo much for verifying!!!

 

[Witzend]

Update on my damper plate mess:
I salvaged the mounting plate from the original R&D damper, manufactured a ring, and bolted the assembly together. In order to insure I had no run out, before I drilled the holes I rotated it on the transmission while observing a deflection gauge. The assembly now positions the damper to within .020 from the inward end of the spine milling where there is no spine wear damage.

 

[rpwillia]

Year and Hull #

Witz, What is your year and hull #? Just curious if this is something I need to worry about.

 

[Witzend]

2001 #83 and yes if it is making a rattling noise, look into it ASAP.

Fred Hutchison of R&D won't come clean on his poor choice of materials for his design on the 22B4, and Westerbeke says it been too long for any warrantee claims. Bottom line, wrong plate for the M25, this should have never happened. Yea maybe the PO idled it a lot, I don't know, but these G.D. engineers should be able to put together a design that can idle without self destruction hell they took us to the moon and back!

 

[Stu Jackson]

Moon???

...but these G.D. engineers should be able to put together a design that can idle without self destruction hell they took us to the moon and back!

Maybe this was the engineering crew that worked up Apollo 13.

 

[paulj]

Witzend and Stu Jackson
Thanks
Back in the 50's and 60's when I worked at the rocket ranch..........
well It just so happens I worked on the Apollo and the Space Shuttle engines.
Can't find the Apollo team picture but found the Space Shuttle team picture.


paulj :troll: