Power Plus 1:23:1

[mevirga]

I think I phrased my last post incorrctly. Still looking for some feedback. Can someone who knows the transmissions and drive systems on these boats, please have a quick read below and let me know if I'm understanding this correctly. My boat is a 99 Air DD with a GT-40.

The issue
There is a rapid paced "rer,rer,rer,rer,rer,rer" noise in neutral coming from the rear of the motor/tranny area. I've narrowed it down to either the clutch or dampener plate. These 2 parts transfer power between the engine & the transmission. The major part flow from front to back is as follows- engine/crankshaft, flywheel, dampener plate, clutch, transmission, drive shaft/prop.

Dampener plate- (part cost +-$100)
This plate bolts to the flywheel and has springs in a circular pattern. It engages the clutch as the boat is shifted into gear. Sometimes this plate becomes loose and/or the springs become unseated and can cause a noise like I'm experiencing. It only does this in neutral because the plate is not engaged to the clutch/tranny and is only spinning with the flywheel, possibly knicking the clutch plate & causing the noise. When the boat is shifted into gear, the noise goes away because the plate is firmly mated with the clutch/tranny. If the spring(s) become completely unseated or the dampener plate loosens entirely from the flywheel, all heck breaks loose and you're stranded on the lake.

Clutch (part cost +- $200)
There are circular clutch plates between the dampener plate and the transmission that are the final transfer of power between the engine and the transmission. If the tranny ever heated up for whatever reason (usually low or dirty fluid) these plates can warp and cause the same issue. Instead it would be a warped clutch plate being knicked by the dampener plate in neutral. The way to test this is to start the boat on the trailer and visually check if the drive shaft/prop is turning. If it is turning, the clutch plates are most likely warped and being knicked by the dampener plate while it's spinning in neutral. If the drive shaft/prop are NOT turning, the noise is most likely coming from a faulty dampener plate.

The noise is most likely originating from this point, whether its warped clutch plate(s) or a faulty dampener plate. The best way to determine which part is causing the problem without tearing into the tranny is to inspect the drive shaft/prop while the boat is running on the trailer in neutral, as described above.

Thanks again for any help.

[steelerguy]

My experience is with an 85 ski supreme and 1990 sport nautique both Direct drives.

The supreme made similar noises when in neutral. Lasted another 2 months then went.
My sport made a little ticking sound. I took no chances and changed it the next weekend.
For the sport one of the springs in the Damper plate cracked and was causing the noise.

Both were Damper plates. Pretty simple to do. An allignment job takes the longest part.

Change the damper plate and hopefully your good to go.

[2gofaster]

Haven't seen it with a nautique, but we had this issue twice with an 05 Responese LXI. Both times it was the damper plate.

[mevirga]

Thanks for the feedback.

I'll do a quick check on the trailer this weekend to make sure it's not the clutch plates and RR the damper plate. Everything is leading in that direction. I will repost when/if resolved. Thanks again.