Replacing Damper Plate

[boatpoker]

This is one of my twin FL 120s in my Grand Banks 42 with tranny and then bell housing removed. No special bracing here. I don't see your problem here.

His problem (like the photos I posted) is that unlike your engine, the rear mounts are on the transmission, not the engine.

 

[rgano]

His problem (like the photos I posted) is that unlike your engine, the rear mounts are on the transmission, not the engine.

Exactly, and the hint was the FL 120 will accept mounts there.

 

[Alisske]

On my boat, a Grand Banks with twin Lehmans 120, the rear motor mount brackets are attached to the gearbox. To those with the same set up, how did you brace the engine, while replacing the damper plate? I was thinking of having engine mount brackets fabricated and mounted to the rear of the engine with old engine mounts to rest on the stringer as my bracing tool. I figured that the old engine mounts will allow me to lower or raise the rear of the engine when reinstalling the engine mount and bracket that are attached to the gearbox. Thanks for your input.

Mine has a similar set up to yours (rear mounts on tranny). I supported the engine off the cooler bolts (see pics). I spoke to Brian at American diesel and he recommended switching to rear mounts on the engine block. I am going to keep it the way it is. I am redoing the four engine mounts this week, so between the damper plate, tranny service and new engine mounts, I don’t plan to take that tranny off for a while, so not worth the extra bucks and hassle to switch.

 

[Alisske]

Just as a follow up. Everything except getting that tranny off was simple. Lmao.

Did the motor mounts while the tranny was out.

 

[catalinajack]

When replacing motor mounts, is an engine realignment advisable. Since the recommended transmission to propeller shaft flange tolerance is no more than about 4/1000 of an inch it seems to me new mounts are likely to change that tolerance such that an alignment is indeed advisable.

 

[Alisske]

When replacing motor mounts, is an engine realignment advisable. Since the recommended transmission to propeller shaft flange tolerance is no more than about 4/1000 of an inch it seems to me new mounts are likely to change that tolerance such that an alignment is indeed advisable.

Yes. Absolutely. I have read that you should check every season. (I’ll check mine every 2-3 years in all honesty.). I have 120hp pushing a 26 foot boat, so with the relatively low torque and RPM, I’m not so worried.

I use the tolerance of 3,000th of an inch. I installed the new mounts 1at a time, and paid close attention to the or existing height of each mount. I replicated that exactly so the mount would be in “mid play” meaning that I had equal amount of adjustment up and down post installment.

Amazingly enough, it was very close to spot on. (I had one very minor rear engine bump to port side to get the final 3/1000)

Very happy about that.

 

[Mako]

What size engine generally do you have to reach where damper plates are no longer employed?

 

[kapnd]

I’d use some kind of flex coupling no matter how small the motor.

 

[Alisske]

What size engine generally do you have to reach where damper plates are no longer employed?

I know I have changed a damper on a universal 25hp diesel. So thats a reference point.

 

[Alisske]

I’d use some kind of flex coupling no matter how small the motor.

I would love to do that, but i am cheap and don’t want to try to figure out how to do it.

I know it seems simple, just cut a few inches off the shaft and put the coupler on, lmfao. But those are “famous last words”

 

[Mako]

I was thinking about the opposite direction. How large? There coMes a size where the flywheel is large and heavy enough withOUT needing a vibration damper.


EDIT: My fat fingers on a little phone - haha

 

[Alisske]

I was thinking about the opposite direction. How large? There cones a size where the flywheel is large and heavy enough with needing a vibration damper.

Lol. My max HP experience was 120hp.

Ill defer to some of the guys that have the “big dog” diesels

 

[AusCan]

My old Volvo 36 hp MD17 didn't have one. It may be due to having such a heavy flywheel which tends to stop the chatter between gears. So engine size alone may not be the deciding factor.

 

[Choices]

The dampner reduces engine pulses and shock loading.

On bigger engines the mass takes that out of the system.

The drivetrain on a 36 trawler is much lighter than a 36 workboat. Although you could argue the abuse would be about the same...

 

[Knot Lost]

Hey folks. Just curious. I’m in the midst of replacing my transmission (the BW Velvet Drive AS3-71CR for my GB32. The new damper plate I got (Alto DA-107) has purple springs. But in photos here, all the ones y’all are putting in have red springs. Alto’s “red” spring ones (da-106) are totally different from mine. Am I missing something? Red vs. purple? Difference? It’s bolting up to the Lehman 2714E, btw.
And I’m still confused about torque spec? The 35 ft-lbs seems a lot! Any pointers or help for a GB newbie?
TIA Scott

 

[Alisske]

Hey folks. Just curious. I’m in the midst of replacing my transmission (the BW Velvet Drive AS3-71CR for my GB32. The new damper plate I got (Alto DA-107) has purple springs. But in photos here, all the ones y’all are putting in have red springs. Alto’s “red” spring ones (da-106) are totally different from mine. Am I missing something? Red vs. purple? Difference? It’s bolting up to the Lehman 2714E, btw.
And I’m still confused about torque spec? The 35 ft-lbs seems a lot! Any pointers or help for a GB newbie?
TIA Scott

I actually looked around the interewebs and see the difference in color, but I think its just that they are different manufacturers.

Good luck with it.

A

 

[SteveK]

Hey folks. Just curious. I’m in the midst of replacing my transmission (the BW Velvet Drive AS3-71CR for my GB32. The new damper plate I got (Alto DA-107) has purple springs. But in photos here, all the ones y’all are putting in have red springs. Alto’s “red” spring ones (da-106) are totally different from mine. Am I missing something? Red vs. purple? Difference? It’s bolting up to the Lehman 2714E, btw.
And I’m still confused about torque spec? The 35 ft-lbs seems a lot! Any pointers or help for a GB newbie?
TIA Scott

The spring color represents a compression measurement. If both the 106 & 107 are spec to your setup then note 106 has 6 springs and 107 has 8

 

[Alisske]

The spring color represents a compression measurement. If both the 106 & 107 are spec to your setup then note 106 has 6 springs and 107 has 8

Damn! Good to know!

 

[Knot Salted]

I consider myself an able bodied person. I have been caring for my Lehman 120 and never miss a service interval. When I got the boat, I redid the head gasket, injectors, injector lines, alternator upgrade, starter, raw water pump upgrade, Fresh water pump, antifreeze overflow system, all hoses, belts etc... All of it was “easy peasy”

The one thing I bought, but never did was the damper plate. It sat in a shelf for a few years, and I put 2000 hours in her. (Took my Groverbuilt 26 from Cape May to The Cape in Mass.)

I decided to do it this weekend. What a bitch. I now know why folks don’t change them. On the surface, easy job. Unbolt prop shaft, push back, unbolt tranny housing, support engine, pull tranny back a few inches, then “just swap out the plate”

Well, my damper was frozen to the splines on the transmission. That meant nothing was coming apart. I’m a big guy and manhandling a BW 72 series tranny was like taking the dog for a walk.

Until this. We must have tugged and sworn at the transmission for 3-4 hours. Finally, the damper plate splits in two (see pick) and the spring part stuck with the tranny, and the other half was still bolted to the fly wheel. All said and done, took me about 5-6 hours and Motrin.

Is there something I could have done to avoid this?

Hi Alissky and Boatpoker,
Do you think that the CR2 72 on Perkins T6.354.4 can be pulled fron the bell housing and the damper changed out through the hole?
Please just give me a text, as I am unable to recover my pass code for TF. To get PMs —-and stranded at Mackinac Island. May just have to limp home on one engine….
Six16.340.6383

ALSO, if someone can help me get back aboard my TF account, much appreciated! (Not getting emails for reset)

Thanks guys!

 

[jgwinks]

My starboard plate blew about a month ago. We were cruising along 12kn 1800rpm when the boat suddenly slowed to 10kn and started a slow right turn. Went down to check and saw the stbd shaft visibly turning slower than the port. So I shut it down and limped in on port. (Docking on one wheel is interesting.) There was no noise or warning, it just let go. When we got the Velvet Drive off I reached in the hole and could turn the damper plate spline by hand. So fortunately it was just the plate that failed, not the trans. Three of the 8 springs were broken and the part that connects the springs to the spline came out in 4 pieces. I found a replacement on fredwarner.net for $147 and put it back together. I'll do the other one after haul out this fall. (I'm in Michigan where nearly all boats come out every winter. Gives us plenty of time to do these things). According to the hour meters the engines only have 800 hours but the boat is 51 years old so I'm suspecting it was more due to rust than wear. The whole plate was pretty rusty. Or, the boat came with a spare set of props and the stbd one was pretty mangled. The PO must have had an incident with it and never got it repaired. That could have damaged the plate enough to cause it to fail later.

 

[Knot Salted]

Hi Alissky and Boatpoker,
Do you think that the CR2 72 on Perkins T6.354.4 can be pulled fron the bell housing and the damper changed out through the hole?
Please just give me a text, as I am unable to recover my pass code for TF. To get PMs —-and stranded at Mackinac Island. May just have to limp home on one engine….
Six16.340.6383

ALSO, if someone can help me get back aboard my TF account, much appreciated! (Not getting emails for reset)

Thanks guys!

Hey!
It turns out that you CAN (YES!) replace the 8 inch damper/drive plate through the hole of the bell housing on a T6.354.4 with velvet drive CR2-72 transmissions. Have to remove two mounting studs after pulling transmission back off the bell housing.

We are on the road again, thanks to Passage Boat Works in De-tour Village, Michigan!

 

[jgwinks]

Hey!
It turns out that you CAN (YES!) replace the 8 inch damper/drive plate through the hole of the bell housing on a T6.354.4 with velvet drive CR2-72 transmissions.

That is IF you can get the 9 Allen head screws holding the damper out. We had to grind/drill 2 of them, that would be pretty hard working through the hole. The bell housing cover comes off with 8 bolts giving full access to the flywheel, but on my engines there's a big after cooler mounted above that has to come off first. It's bracket bolts to the bell housing cover. Well worth trying to do it through the hole if you have that setup.

 

[Irish Rambler]

I have a 1982 Albin 40 with a 135 hp Ford Noreast diesel (similar to a Lehman) and a Borg Warner 1013 transmission. I have owned the boat since 2005. I have never replaced the damper plate and based on the skills of the previous owner, neither did he. My transmission is working fine but it doesn't get a lot of heavy use because I do most of my cruising here in Nova Scotia just in August and September because of time constraints. My question is, should I proactively pull the tranny and replace the DP even though there is no indication of a problem? Even though I am getting good performance now, is this thing about to turn to dust?

Thanks to all who reply (especially Jay Leonard because I'm sure you've already done this with your boat).

Jeff

I've been in your situatuation and mine just quit as I approched the dock with a very gentle touch, very lucky ! It's not to difficult but I would respectfully suggest as it's a single engine that you fit a 'heavy duty' replacement. Clean the area around, have a couple of old plastic food boxes for your bolts etc. Disconnect the propshaft and slide it back, then all the pipes. Its a good time also to descale your gearbox heat exchanger. Drain the gearbox to a, reduce weight and b, service it. disconnect the bolts holding the g/box (don't forget the one underneath). Get someone to give you a lift, sling a rope under to take the weight, withdraw it and place it down gently in the bilge. Remove the adapter plate and then your clutch damper plate. Replace in the reverse order using 'locktight' on internal bolts. Before replacing the gearbox check seals for leaks. Flush gearbox with clean oil before refilling. Pay particular attention to the clearance on the flexible coupling alignment bolts to the shaft, be absolutely meticulous and get them perfectly checked to the mm. Clean up everything, have a shower and crack open a bottle of Tullamore Dew Irish Whisky as your reward for a job well done.