View Full Version : damper plate? 88 PS190

07-27-2010, 07:34 PM
ok, so I read all the threads I could find on front and rear seal replacement on a velvet drive 1:1 for my boat, and everything was going just as I expected until I pulled the tranny away from the bell housing. I was expecting to see a damper plate as noted in other threads, but what I found didn't look the same at all. Attached to the input shaft is a geared disk with rubber boots over the teeth, and on the flywheel is a matching receiver. It appears to serve the same purpose as a damper plate, but I can't get the geared plate off the input shaft. It was bolted with six socket head capscrews, and has two threaded holes (for a puller maybe?). Anyway, I removed the capscrews, attached my puller and tried to pull it off the shaft. Bent the puller, but nothing budged. Is there something else I should be doing to get this off?



07-27-2010, 08:55 PM
I have changed out the damper on my old 86 MC with the 351 ford but that looks alot more heavy duty than the standard plate. Does the boat have a big block motor? Was it a ski show boat? I 'm sure someone here could give you some good info on it.

07-27-2010, 11:30 PM
Has a 351, and the two previous owners were just avid skiers.

07-28-2010, 11:02 AM
Wow, what the heck is that;-)

07-28-2010, 12:33 PM
I'd be interested in hearing from anyone who knows what this is. Just for curiosities sake.

07-28-2010, 01:04 PM
Same concept as a Cush drive in a Motorcycle.. The Rubber fittings make for a very smooth drive... I would go for a better Puller if I were you.. Also make sure your using that puller correct... Tighteng the outside bolts.. Not the center one...

07-28-2010, 01:10 PM
Looks like an upgrade for high hp engines, that is a lot of steel, crazyness.

There is not a flange on the transmission which leads me to believe those six bolts are squeezing in the female splines to lock that "gear" onto the transmission input shaft (which explains why the splines are cut into thirds). In a typical setup, the splines are free to translate, but it makes sense with his setup that "gear" has to be connected to the input shaft.

I am thinking the female spline section uses a taper interface to mate with the gear. It uses a flange behind the gear which accepts those bolts. As the six bolts are tightened into place the taper is squeezed tight, which squeezes the female splines onto the input shaft. Does that slot between the female splines and the gear have a woodruf key in it? If so I will feel more confident that this is how it works.

I would suspect you have some corrosion that is not allowing the gear to slide off the taper. I would start with a heavy bath of penetrating oil such as liquid wrench (put a bunch into the bolt holes as well as the taper to try to get oil into the flange/gear matting surfaces). Then I would try the puller while tapping on the female splines to see if the taper will separate. Since you are replacing the seals you can probably apply some heat, but I would only do that as a last resort.

Hopefully somebody who has actually seen one of these before will come along. They will probably have much better advice than me.

07-28-2010, 04:11 PM
WTHeck is that?

07-28-2010, 08:58 PM
Looks like I owe Luv2Ski a beer or six....It was exactly as described, and after cranking on the puller and applying a bit of percussive persuasion, the outer piece came off...with authority! Good thing my fingers weren't in the flight path! The inner piece was just a snug fit and came off easily.

Anyway, boats almost back together and should be in the water tomorrow. Thanks for the help!



07-28-2010, 09:26 PM
ok, someone with some knowledge needs to explain with some authority what that thing is?

07-29-2010, 08:44 AM
Looks like I owe Luv2Ski a beer or six....It was exactly as described, and after cranking on the puller and applying a bit of percussive persuasion, the outer piece came off...with authority! Good thing my fingers weren't in the flight path! The inner piece was just a snug fit and came off easily.

AWESOME... cause I am THIRSTY (it is 5:00 somewhere)!

Glad my guesses lead you on the right path. I should have thought about it coming off in a hurry - just like a propeller can fly off its taper when removed. Next time mayble leave a bolt or two in there and loose to catch the gear.

One additional thought, you might want to put a little anti-size compound in there when you re-assemble. That might help it come off easier next time, although it sounds like once you had the technique it was not too bad.

I still say that is a cool setup. It looks like it would be very strong, doubt you will ever have a broken damper plate.

Enjoy your leak free trans!

07-29-2010, 02:32 PM
Anti-seize is your friend on things that you might want to remove again when it is metal to metal contact. I put it on all shafts ends, couplers, bolts and especially spark plug threads. Never had anything vibrate loose yet if torqued to specs. I use loctite when I bolt together soft materials that compress and release.

07-31-2010, 04:08 PM
Can anybody give us some onfo on this damper plate?

09-29-2010, 12:43 PM
Found out more details on this plate. It is a "Suredrive" from NextWave Marine Systems. The previous owner had it installed after the original plate failed. I actually found the documentation for it in all of the paperwork the previous owner supplied when I bought it (oops, should have looked there first...).


09-29-2010, 07:42 PM
I sent them an inquiry regarding pricing/availability. Anyone have any idea on the price...haven't gotten a response yet. I'm due for a damper plate, this may be a good option if it's not too expensive.

11-06-2010, 03:49 PM
so, I got a response.....855.00 + shipping!!! Wow, no thanks.