My starboard 470/3.7 won't go into any gear Help!

[nsbandc]

I have an 84 Stamas with twin 470's. I was running the boat at about 3000RPMs and all of the sudden the engine made this sound like they had been opened into full throttle. I opened the engine hatch and the starboard engine had shut off on it's own but the port was still on. I shut off the port and let both cool down. When I restarted the port had no issues but the water temp gauge needle for the starboard was reading at such a high temp. it was almost off the guage. When I tried to put the port into gear no prob. the starboard wouldn't go into gear at all and the water temp was saying it was getting hotter and hotter. I limped back in on the port engine and I have no clue now whats wrong with it there is no visible leaks everything that should be turning freely is. Any help would be greatly appreciated! Thanks in advance!

 

[Haut Medoc]

Re: My starboard 470/3.7 won't go into any gear Help!

A quick way to see if you have drive damage would be to put drive in fwd at helm, and see if you can turn the prop by hand. [Shut off battery switch or disconnect battery first]. You should be able to turn the prop one way but not the other. In reverse it should catch in the opposite direction. If you can turn it both ways in gear your drive very likely has internal damage. If the lower drive shaft is not spinning, neither is your impeller.....J

 

[lenny2113]

Re: My starboard 470/3.7 won't go into any gear Help!

Welcome to Iboats forum.<br />If you have an I/O it sounds to me like you have a damaged outdrive. It could be quite a few things at this point. I would guess it could be stuck gear. Pull the drive...<br /><br />Better yet, provide more info on the setup. Is it an Inboard or I/O? What type of drive or tranny is it?

 

[nsbandc]

Re: My starboard 470/3.7 won't go into any gear Help!

Thanks for your quick responses! I am going to try and turning the prop and see what happens like you said. It is a Mercruiser 470 or 3.7 and they are I/O's. Thanks again. Any more ideas on what could be wrong or how to check would be great. I'll go and check the props in the meantime. Thanks!

 

[DJ]

Re: My starboard 470/3.7 won't go into any gear Help!

I would be looking for water pump issues. If the 470 got that hot, it may have engine problems. That's an aluminum block with a cast iron head.

 

[sigep0435]

Re: My starboard 470/3.7 won't go into any gear Help!

If you put the drive in fwd, should the prop spin at all? I thought it took engine power to engage those gears. I'm not an expert by no means, but I went out and tried this myself, b/c I've been having drive problems also, and in fwd or rvs, it's locked and won't move either way. Just wondering, maybe mine is screwed, that's why it won't move.

 

[Haut Medoc]

Re: My starboard 470/3.7 won't go into any gear Help!

Standard rotation engine: 1) Prop will spin both ways in neutral by hand. 2) Prop will engage turning prop ccw with helm in foreward and you should not be able to turn it any further after it engages. You can turn it clockwise at this helm position and it will not engage. 3) With helm in reverse you should be able to turn the prop clock-wise until it engages and no further. Simply put, the drive should engage one way or the other while in gear, if it doesn't, you most likely have internal drive problems....Hope this clarifies.....J

 

[Don S]

Re: My starboard 470/3.7 won't go into any gear Help!

I was running the boat at about 3000RPMs and all of the sudden the engine made this sound like they had been opened into full throttle.

This statement along with the overheat makes me think you lost the coupler. With the splines out of the coupler, you wouldn't be running the raw water pump that is in the drive. And as hot as you got the engine, you may have other problems with the engine as well.

 

[Haut Medoc]

Re: My starboard 470/3.7 won't go into any gear Help!

Question for Don S.: If the splines on the coupler were shot, would it do any damage to the shaft on the drive? Or, is it more like a prop hub deal? Would you be able to turn the drive in gear by hand?..............J

 

[nsbandc]

Re: My starboard 470/3.7 won't go into any gear Help!

Thanks everybody for your help!I did what J.kopec told me to do with the prop and it performed exactly as you said it should so I guess that means it's internal issues then. From what I'm understanding I need to look at the water pump and the coupler splines. Any other suggestions on things I should be checking out. Thanks again folks I appreciate it!

 

[Haut Medoc]

Re: My starboard 470/3.7 won't go into any gear Help!

Your water pump might be O.K. If the coupler is bad like Don S. thinks it might be.....That's not so good. Pull the drive off and see how it works by hand as I described above....J

 

[Don S]

Re: My starboard 470/3.7 won't go into any gear Help!

You can shift the drive and and try turning the prop and everything may look fine, even with a spun coupler. Just the resistance between the coupler and the shaft will make it impossible to turn by hand.<br />It's time to pull the drive and look at the splines in the coupler. And yes, the splines on the shaft will wear out just like the ones in the coupler. The whole problem can be avoided by yearly checks of the alignment. Bad mounts both front and rear can cause the couplers to go bad very quickly. Just replacing the coupler and not repairing the cause will require a second coupler very soon.