Power Plus 1:23:1 noise
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=17686
Printed Date: November-18-2024 at 4:29pm
Topic: Power Plus 1:23:1 noise
Posted By: mevirga
Subject: Power Plus 1:23:1 noise
Date Posted: May-23-2010 at 3:25pm
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Hello-
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. |
Replies:
Posted By: Kristof
Date Posted: May-23-2010 at 4:22pm
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Mister Lavine... This is one for you!!
Mike, Eric Lavine is our transmission guru. He'll chime in soon. ------------- - Gun control means: using BOTH hands! - Money doesn't make one happy, but when it rains cats and dogs, it's still better to cry in a Porsche than on a bicycle... |
Posted By: mevirga
Date Posted: May-23-2010 at 4:27pm
| Thanks Kristof. Much appreciated for taking the time to pass me to the right person. Look forward to Erik's response. |
Posted By: mevirga
Date Posted: June-04-2010 at 9:28pm
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Is Eric still out there?
Thanks. |
Posted By: jimsport93
Date Posted: June-04-2010 at 10:08pm
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Maybe working overtime on Nautiquechick's tranny! ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=2798 - 93 Sport Nautique |
Posted By: M3Fan
Date Posted: June-04-2010 at 10:59pm
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Just to clarify, clutch plates are inside the tranny and are nowhere near the damper plate. They are part of the transmission, deep inside the trans. They do not engage the damper plate in any way, shape, or form.
The damper plate goes exactly where the clutch plate/pressure plate or torque converter would go in a car- in the bell housing. There are zero clutchlike mechanisms in the bell housing of your boat. ------------- 2000 SN GT40 w/99 Graphics/Gel 2016 SN 200 OB 5.3L DI https://forum.fifteenoff.com |
Posted By: eric lavine
Date Posted: June-04-2010 at 11:33pm
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gd damn, that ones way out there...
damper, as what it says, dampens torsional or cushions torsionals, anytime the engine is running the damper is spinning and spinning the input shaft of the transmission. it takes roughly 900 degrees to warp a clutch plate and steel, nothing on an engine gets to 900 degrees, (except in the heart of the combustion chamber)these are wet clutch plates that run in an oil bath inside of the transmission relying on coefficient of friction to keep them from slipping, they rarely slip at idle and need a reason to slip, IE., low oil, worn pump, hard seals. wet clutch plates do not wear like a dry clutch and need adjusting. I'm not saying they don't wear, they actually do but only a couple of thousandths and many hours. Basically a transmission operates on hydraulic theory, pressure behind a piston that pushes against internally splined clutch plates and externally splined steel plates staggered normally in order of steel, clutch, steel, clutch, and so on, the more the plates the more the holding capacity, the bigger the piston the more psi, on the clutches and the more the oil pressure the better the hold. I get asked all the time, why don't these transmissions have a torque converter? the slip is at the prop and power transfer is a true 1 to 1, unlike a car that has a solid object hitting the ground which is referred to as a tire, on a car it is truly locked in gear but the converter does the slipping and has no mechanical connection thus letting the car sit and not stall and a good example with a boat would be to back it into a sand bar and throw it in gear, the end result would be the engine would stall because it is a true mechanical connection, if it had a torque converter it would allow the slip and wouldn't stall the engine. A good way to imagine a torque converter would be to take 2 fans and face them towards each other and turn one on, we all know what happens, the other fan starts to turn... this is exactly how a converter works, instead of air though the basic principle is still the same with oil so, change your damper and it will fix your problem and don't try to figure this stuff out because it is mind boggling ------------- "the things you own will start to own you" |
Posted By: eric lavine
Date Posted: June-04-2010 at 11:45pm
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btw, if a clutch plate and steel slips it will slip on power up or under high RPM's, and when they slip they will hit temperatures in excess of 900 degress and at times will weld themselves together because of the high heats, and they need a reason to slip such as discussed earlier ------------- "the things you own will start to own you" |
Posted By: akabulla
Date Posted: June-05-2010 at 12:26am
| Just to make sure you do say above it happens in neutral, correct? Cause while in gear the 1:23:1 typically does makes a high pitch squealing noise. That is how I know my shaft is turning :) |
Posted By: 8122pbrainard
Date Posted: June-05-2010 at 10:07am
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Mike,
You're thinking too much "high school auto shop". Get automotive out of your mind. There are absolutely no similarities between auto and marine except one end turns and makes the other end turn. Look though a marine trans manual and you may get a better picture. There are some trans manuals in the reference section. It doesn't matter which brand you look at. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: eric lavine
Date Posted: June-05-2010 at 10:15am
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the one thing about a PCM trans is you may get some planetary noise in neutral, they are spur cut, not bevel cut and spur (straight cut gears) have a tendency to whine and another good example of spur cut gears are in an automotive application. on a standard shift car if you ever noticed backing in reverse you will get a whine and it will at times grind when shifting the trans into neutral, the reason is reverse does not have a synchro on it to speed up the gear to get into the next speed so the engineers cut the gear straight in order to slide the idler (reverse gear) into the cluster gear. and that is what you hear whining on reverse. The pcm, unlike the borg warner uses all straight cut gears (except in the tail section of the 1.23's) but for the most part you are probably hearing some neutral gear whine and it is being aggravated by a weakening damper.
the damper is a crucial part of the drive line, its job as another analogy would be to take a coil spring from a car and weld a flat plate on top of it, and then take a jack hammer and stand over the spring and nail it with the jack hammer, the springs will absorb the shock of the jack hammer, but after time the spring will weaken or crack and will start to hit the other coils and start rattling...this is what happens with a weak damper, with out the damper the jack hammering effect would be transmitted right into the transmission, and you know what happens when you hit the jack hammer on solid concrete..something breaks ------------- "the things you own will start to own you" |
Posted By: kapla
Date Posted: June-05-2010 at 11:13am
nice clear explanation..Eric....
 ------------- <a href="">1992 ski nautique |
Posted By: mevirga
Date Posted: June-08-2010 at 11:57pm
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Thank you so much everybody. Yes, I was thinking autoshop. Bad news though....I pulled allt he tranny fluid out and found it not to be clear. Dirty and kinda pink in color. Like water had been mixed with it. I am planning on running it this weekend to see if the trannt fluid gets contaminated with water again. If so, most likely tranny cooler? Not even sure if this has anything to do with the neutral noise whick sounds like it's coming from the bell housing. Again, the boat drives perfect and the prop&shaft are still on the trailer when running, able to turn with normal hand pressure. Crap. kinda at a new stage. hate to teardown and rebuild a transmission that works perfectly, a pink frothy mix in the tranny's now good. And then there's the neutral noise that seems to be a damper plate. I know the normal nautique whine in gear which is there and fine. Any suggestions?
Thanks again for all the help and advice. mike |
Posted By: eric lavine
Date Posted: June-09-2010 at 9:04am
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wont be long........PCM transmissions dont like water for any amount of time. ------------- "the things you own will start to own you" |
Posted By: 8122pbrainard
Date Posted: June-09-2010 at 9:04am
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Mike,
Before you take the chance of damaging the trans more that it potentionally is, pull the trans cooler and pressure test it. Find the source of the water. Then do a couple oil changes on the trans to get rid of the water. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: mevirga
Date Posted: July-07-2010 at 4:44pm
| All looks to be good now. Had Larsen Marine in Stockton, CA change the damper plate. They found it to be rusty with 1 loose spring. Good news though, no more neutral noise. I also changed out the tranny cooler just to be safe and have not seen evidence of any water in the fluid. ran the boat hard for 4 days last weekend and everything is good. Thanks for all the help. |
Posted By: Sephmu
Date Posted: July-07-2010 at 6:42pm
| well spoken eric |