2002 Launch SS transmission "clunk"

[Zkdk3000]

Purchased an 02 Launch SS over the winter, today was first start up. Engine ran fine and after allowing it to reach operating temp I engaged the transmission into forward and then reverse. The first time engaging into both forward and reverse I did not hear anything out of the ordinary, engaged smoothly. The second and third rounds the transmission made a loud clunk engaging in both forward and reverse. My other boat is a 92 Comp ts6m (first boat ever) and I've not ever heard a loud or aggressive sound when engaging trans. This being my second boat I am unsure whether this is normal or not, and I have done some research that states some boats make a clunk when engaging trans and can be normal.

There never seemed to be any slip or hesitation the prop spun freely and immediately once I engaged shifter. I checked the trans level immediately after shutting boat off and the fluid looks pretty accurate (boat is level and on trailer with water supplied into fake a lake from hose). Color also looked good so I would assume the trans fluid has been changed although I can't say how long ago. Boat has 277 hours so there's a possibility it's factory fluid or close to.

If anyone can tell me whether or not this is normal or what to look for I would greatly appreciate it. Thanks.

Z

[Jetlink]

My question is why engage the transmission out of the water especially on a trailer?

[Zkdk3000]

You're telling me if you bought a boat you wouldn't test the trans before putting it in the water?

[ngavchris]

Congratulation on your purchase. I frequently run my boat on the trailer hooked to a bucket. I'll put mine in and out of gear also. I normally spray the prop and driveshaft before doing this. I've never had an issue doing this.
How loud was the clunk? I would say that this is not normal. Did the prop still spin when in gear? My brother had is bolts come loose on the drive shaft. I would check to make sure they are tight.
Keep us posted.

[Zkdk3000]

Congratulation on your purchase. I frequently run my boat on the trailer hooked to a bucket. I'll put mine in and out of gear also. I normally spray the prop and driveshaft before doing this. I've never had an issue doing this.
How loud was the clunk? I would say that this is not normal. Did the prop still spin when in gear? My brother had is bolts come loose on the drive shaft. I would check to make sure they are tight.
Keep us posted.

Thank you for the reply! The clunk is loud enough to consider it concerning, it does not sound normal to say the least. The prop did spin when put into gear and stopped when put into nuetral. I will check the bolts today. One thing I did fail to mention, and after thinking back, that after the first time I put the boat into gear the RPM's did not return to normal. Therefore the following engagement was at around 1000rpm. This leads me to believe the clunk is a hard engagement due to the higher RPM's. After revving the boat a few times the RPM's floated around 1200. I know enough about mechanics to make me believe I have a faulty Throttle Position Sensor which is usually the case with a floating idle.

I went ahead and purchased a TPS for a 95 Chevy 1500 and it fit perfectly. Unfortunelty the fuel pump just happened to burn out so I was unable to fire the boat.

It turns out finding a fuel pump for this engine is a huge pain in the ass, and I have not been able to find a certain pump to replace the OEM. GM stopped manufacturing the direct replacement a few years ago. Do you mind if I pick your brain over this issue? I have narrowed it to three pumps but need additional info to make a choice. Thanks in advance.

Zk

[docdrs]

You're telling me if you bought a boat you wouldn't test the trans before putting it in the water?

I would never buy a boat with out testing it in the water first!

Back to your issue......it def could be due to shifting at increased rpm and shifting out of water with no load on the prop and dry prop shaft bushings

[NorCalPR]

I would never buy a boat with out testing it in the water first!

Back to your issue......it def could be due to shifting at increased rpm and shifting out of water with no load on the prop and dry prop shaft bushings

This

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[Zkdk3000]

I would never buy a boat with out testing it in the water first!

Back to your issue......it def could be due to shifting at increased rpm and shifting out of water with no load on the prop and dry prop shaft bushings

Bought it off eBay pictures and description only otherwise I def would have test driven it. So it is recommedned then to not engage trans out of water? I replaced the fuel pump and TPS sensor but the high idle remains. I'm sure it won't do the trans any good shifting into forward at 1k plus RPM's. When I first start the boat the idle is aboit 950. When I give it gas and let off, the idle will not return to 950 but floats around 1500/1600. If I shut off the boat and re-start it it will return to 950 until I give it gas. I'm thinking IAC, TPS, vacuum leak. I have not found any vacuum leaks and I replaced the TPS. What do you think? If IAC is possibility I'll run to oreillys and pick one up just to make sure.

Zk

[Zkdk3000]

SOLVED.

Clunk was from high idle of 1000rpm+ causing hard engagement. Culprit was a bad IAC valve. Thanks all.


Zk