Replacing damper plate on a Universal M25 at anchor

[Natedogg]

This past spring my wife and I were sailing our 1984 O'Day 34 in the Bahamas and a rattling noise started coming from the engine. Eventually we figured out the noise was coming from the bell housing of the engine (Universal M25 diesel), and not just a noise but we saw small metal shavings coming out of the timing port on the housing. With the help of the internet and a couple invaluable (and much more knowledgeable) friends we figured out that the issue was likely the damper plate. There was some info that we couldn't find online, or found contradicting information for, so I wanted to fill in some of those gaps to help the next sailors in need (and pay forward some of the help I received!).
After getting to an anchorage and scouring the internet for information we drained the coolant, detached the raw water hoses, removed the heat exchanger, detached the transmission linkage, detached the grounding wires, and detached the propeller shaft from the engine coupling, good and rusty but we got there eventually. On the Universal M25 the transmission is attached to the bell housing from the inside of the bell housing, so we had to remove the whole combo. There wasn't enough room between the shaft and the transmission to slide the transmission/bell housing back and off to expose damper plate and the flywheel, so we needed to lift the aft side of the engine. The O'Day 34 engine room doesn't have vertical access, so we didn't have the option to hoist the engine, so we took a friends creative advice. We outlined the engine mount locations, then removed the engine mount nuts, deflated a small fender, shoved it in the 3" space between the transmission and the engine room floor and used a bike pump to inflate the fender. We placed 2x4's under the oil pan to support the engine, deflated the small fender, replaced it with a larger deflated fender, and then inflated that too. The second bigger fender (which didn't fit under the engine initially) lifted the engine enough to clear the propeller shaft. We stacked more 2x4s under the engine and then deflated the fender lowering the engine onto the wood.
The exhaust manifold came very close to needing to be removed to lift the engine high enough but we were able to squeak by without taking it off. We tied lines to the engine hoist points to keep the engine from shifting backwards in case we got waked by a passing boat, and then started working on detaching the bell housing from the engine body. There are nine bolts holding the bell housing in place, but embarrassingly I thought there were 10, and after some serious struggling and a short stint with a power drill trying to drill out what I thought was a broken bolt, I realized the top center "bolt" was just a peg for holding the housing in place.

Once we got the bell housing/transmission off we found our damper plate in about 6 pieces. The springs and broken pieces of the damper plate had been rolling around in the bell housing shaving it from the inside causing the metal shavings we'd seen coming out of the timing port.

Now that we'd confirmed the issue we needed to replace the plate. Online there's a mix of what damper plate people say to use, for the Universal M25: Sachs 1866061001/3306316002 and/or Sachs 1866050002/3306316001. Amazingly someone in the anchorage had the first (3306316002) but it was clearly far too big for the flywheel on the M25. The correct model is the 3306316001, which we had flown in on Water Maker Air from Fort Lauderdale (only took 8hrs!!!).


With the new damper plate installed we put the bell housing and transmission back in place. We used a screw driver shaft to line up the holes and support the housing while installing the first bolts. Doing all this in the confined space of the O'Day 34's engine room was a real curse word inducing experience so that screw driver trick put an end to a lot of heart ache (again advice from a friend). We borrowed some feelers from another neighbor for the alignment (have since bought our own) which was good since we did have to tweak the position of the engine a little even though we put it back where we'd marked the mounts. We got all the hoses, wires, and cables reattached and our engine was back in action for the rest of our Bahamas cruise. It wasn't fun, but it was a learning experience. Hopefully this info along with the photos and the guidance already out there helps someone else in getting through the same problem.

[Compass790]

Good post Natedogg. I liked the pumping up the fender trick for a jack. Are the damper plates a common problem? How many hours on the engine?

[Captain Bill]

Originally Posted by Compass790

Good post Natedogg. I liked the pumping up the fender trick for a jack. Are the damper plates a common problem? How many hours on the engine?

I had a Yanmar mechanic tell me that Yanmar and other spring type dampers are only good for about 1200 hours or so on small diesels. He said that if you have the transmission off you should check the damper and if the springs are loose in their mounts or there is obvious wear on them they need to be replaced. Two years ago I was having a problem with my saildrives repaired under warranty at 1200 hours and had the dampers replaced. The springs in the old ones were loose and rattling around. The new ones were nice and tight. They might have lasted a bit longer but since the engine was already disconnected from the drive it seemed prudent to replace them and avoid another engine removal project in the near future.

[RickG]

Thanks for the post. The fender idea is awesome! Our Volvo Penta D2-55 is notorious for going through damper plates. I love the fender idea. We have enough room for a small hydraulic jack under our engine. Getting a good alignment afterwards is an art.

Cheers, RickG

[Natedogg]

Glad you all like it! I was excited about the fender too, something we all have onboard and it worked like a champ! Compass790 the engine is a 1984, and given how terrible the condition of the damper plate was it clearly should have been changed earlier (the engine hrs counter stopped before we bought the boat, so not sure what its hours are now). Maybe the damper has been changed since its build, but in the last 3 years we’ve had it we’ve not changed it. Truth be told I’d never heard of a damper plate before dealing with it, but after talking to other cruisers it sounds like a semi-regular maintenance item. Pretty much like Captain Bill said, if you’ve got the transmission off you might as well replace the damper to avoid having to take it all apart again later. RickG awesome that you have that space under your engine. I walked all over Staniel Cay talking to locals and trying to track down a car jack, but it turns out there wasn’t enough space for even a skinny car jack to fit under the engine (also so many people drive golf carts on the island it was surprisingly hard to find a jack!).

[geoleo]

Originally Posted by Natedogg

This past spring my wife and I were sailing our 1984 O'Day 34 in the Bahamas and a rattling noise started coming from the engine. Eventually we figured out the noise was coming from the bell housing of the engine (Universal M25 diesel), and not just a noise but we saw small metal shavings coming out of the timing port on the housing. With the help of the internet and a couple invaluable (and much more knowledgeable) friends we figured out that the issue was likely the damper plate. There was some info that we couldn't find online, or found contradicting information for, so I wanted to fill in some of those gaps to help the next sailors in need (and pay forward some of the help I received!).
After getting to an anchorage and scouring the internet for information we drained the coolant, detached the raw water hoses, removed the heat exchanger, detached the transmission linkage, detached the grounding wires, and detached the propeller shaft from the engine coupling, good and rusty but we got there eventually. On the Universal M25 the transmission is attached to the bell housing from the inside of the bell housing, so we had to remove the whole combo. There wasn't enough room between the shaft and the transmission to slide the transmission/bell housing back and off to expose damper plate and the flywheel, so we needed to lift the aft side of the engine. The O'Day 34 engine room doesn't have vertical access, so we didn't have the option to hoist the engine, so we took a friends creative advice. We outlined the engine mount locations, then removed the engine mount nuts, deflated a small fender, shoved it in the 3" space between the transmission and the engine room floor and used a bike pump to inflate the fender. We placed 2x4's under the oil pan to support the engine, deflated the small fender, replaced it with a larger deflated fender, and then inflated that too. The second bigger fender (which didn't fit under the engine initially) lifted the engine enough to clear the propeller shaft. We stacked more 2x4s under the engine and then deflated the fender lowering the engine onto the wood.
The exhaust manifold came very close to needing to be removed to lift the engine high enough but we were able to squeak by without taking it off. We tied lines to the engine hoist points to keep the engine from shifting backwards in case we got waked by a passing boat, and then started working on detaching the bell housing from the engine body. There are nine bolts holding the bell housing in place, but embarrassingly I thought there were 10, and after some serious struggling and a short stint with a power drill trying to drill out what I thought was a broken bolt, I realized the top center "bolt" was just a peg for holding the housing in place.

Once we got the bell housing/transmission off we found our damper plate in about 6 pieces. The springs and broken pieces of the damper plate had been rolling around in the bell housing shaving it from the inside causing the metal shavings we'd seen coming out of the timing port.

Now that we'd confirmed the issue we needed to replace the plate. Online there's a mix of what damper plate people say to use, for the Universal M25: Sachs 1866061001/3306316002 and/or Sachs 1866050002/3306316001. Amazingly someone in the anchorage had the first (3306316002) but it was clearly far too big for the flywheel on the M25. The correct model is the 3306316001, which we had flown in on Water Maker Air from Fort Lauderdale (only took 8hrs!!!).


With the new damper plate installed we put the bell housing and transmission back in place. We used a screw driver shaft to line up the holes and support the housing while installing the first bolts. Doing all this in the confined space of the O'Day 34's engine room was a real curse word inducing experience so that screw driver trick put an end to a lot of heart ache (again advice from a friend). We borrowed some feelers from another neighbor for the alignment (have since bought our own) which was good since we did have to tweak the position of the engine a little even though we put it back where we'd marked the mounts. We got all the hoses, wires, and cables reattached and our engine was back in action for the rest of our Bahamas cruise. It wasn't fun, but it was a learning experience. Hopefully this info along with the photos and the guidance already out there helps someone else in getting through the same problem.

yOUR A fox!

[boatpoker]

Next time (hope there isn't one) consider going to a polyurethane damper and avoiding those terrible springs.

[Hulabaloo]

Thanks for the great write-up natedogg. I have a universal m25xp in my ‘87 Catalina 30. Yesterday after repairing some engine wiring I fired the engine up and after a minute or two of idling it gave a momentary rattle. Within a few minutes the momentary problem had drastically worsened. Here is a short video I took just before shutting it down. trying to figure out where to start and hoping you will give it a listen and tell me whether this is what your problem sounded like. Thanks!
https://youtu.be/YdtSULjHrrg

[Orenda 1]

Originally Posted by Hulabaloo

Thanks for the great write-up natedogg. I have a universal m25xp in my ‘87 Catalina 30. Yesterday after repairing some engine wiring I fired the engine up and after a minute or two of idling it gave a momentary rattle. Within a few minutes the momentary problem had drastically worsened. Here is a short video I took just before shutting it down. trying to figure out where to start and hoping you will give it a listen and tell me whether this is what your problem sounded like. Thanks!
https://youtu.be/YdtSULjHrrg

Hi all, i have 1984 m25, hurth transmission on my Cataline 30. Just set out for a 10 day cruise, only to hear metallic rattlel after 1st day out. It occurs only when in gear. One mechanic said it was probably the transmission, as the damper plate is always spinning with the engine, so if it were bad, the sound wouldnt likely change much in or out of gear. Thoughts? Also, good source for the plate? Catalina direct wants $676 for this puppy. !

[Manateeman]

We’ve been on a boat that had an oiling system on their bell housing. On top, an oil cup and on the bottom a cup to collect the dirty oil. Interesting.
We know another diesel mechanic who washes a new plate with acetone and fills the springs with 5200. Learned this in Acadian Louisiana.
Who knows. Maybe it’s just the rust that kills the springs or shifting at too high RPM ? Does a drive saver extend the life?
Inquiring manatees await your learned counsel.
The blubber butt crew.

[Natedogg]

Orenda 1: I can't remember if we heard our rattle the same in and out of gear, sorry about that. I ended up getting our damper plate from marinegears.com in Ft. Lauderdale, but I had also put in an order to Fredwarner.net that would've taken a couple more days but looked like a good option (https://www.fredwarner.net/product/s...engine-damper/). Good luck!
Manateeman: I wish my counsel was more learned, but in our case our damper plate was rusty garbage by the time we took it out. That oiling system would make a lot of sense. Did we send our damper plate to it's grave with poor shifting? Maybe. We don't try to abuse our engine but I certainly have been guilty of shifting into reverse before the prop stops spinning after shifting into neutral, and vice versa probably. Solid crew name.

[Orenda 1]

Thanks for your responses. I am unsure if the sounds are indicative of damper plate or transmission- assuming one or the other is headed for the cemetery. Probably do a visual inspection of the plate and go from there. Thanks again...

[RaymondR]

Living in a damper plate bolted to the flywheel of a diesel is a pretty hard life for a spring.

[boatpoker]

Originally Posted by RaymondR

Living in a damper plate bolted to the flywheel of a diesel is a pretty hard life for a spring.

I agree.
Thats why I prefer the polyurethane damper plates.
https://marinepartssource.com/plate-...gaAk-OEALw_wcB

[Orenda 1]

"Living in a damper plate bolted to the flywheel of a diesel is a pretty hard life for a spring...", yeah, sounds like a bad marriage with 5 kids.