Issue with Coupler/Outdrive??

[wakeup 19]

I have been having an issue with my stbd engine propulsion.
Engine runs great
I changed props this season because I thought the issue was prop related but it does not appear to be the case.
I go out for a ride and all is well. go thru the locks, hit throttle and all is fine. I hit another no wake zone and put along. All is fine
then I throttle up again and my stbd drive will not give me any power?? Engine is working fine. It "feels like a spun prop but I had the problem last year with a brand new prop and I changed the prop and hub to a different prop this spring and am now experiencing the same problem.
If it was a coupler wouldn't it be slipping all the time not just when it gets "warm"? no rubber smell or particles on shaft at coupler.
Could it be a drive issue? original Alpha one gen 2 drives?
It runs fine till I take it off plane and then try to get back on plane.
The next day it will do the same exact thing.
I marked the drive shaft and coupler late yesterday to see if they change rotations. Have not gone back out to test it yet, hopefully I can see back there very tight.
Anyone experience this on their boat??:smt021:huh:

 

[Lazy Daze]

It sounds like a failing coupler, to me. It wouldn't necessarily be spinning all the time, until it get's worse. FYI, if by chance you're using a newer style prop (actually, been in use for quite some time), they don't even have a traditional "hub" like you're probably used to dealing with. If the problem was in the drive, I would think it would be a major issue with the gears and that would sound MUCH different.

 

[wakeup 19]

The hub is a plastic on the Michigan Wheel, and rubber on the Hill Marine prop.
is the coupler getting warm then slipping? Next day same thing.

 

[Lazy Daze]

Yeah, those plastic ones won't "spin" like you're used to - if they go, they're gone.

I've never really thought about cold vs hot in regards to a spun coupler. I do know that you won't always get a smell or lot's of rubber particles - at least not in the early stages of coupler failure (usually, anyways). I suppose there's different aspects to talk about - the rubber would get more flexible as it gets warm and possibly slip easier... but then there would also be some expansion, which would counter that. I suppose it comes down to whichever variable is larger - with preliminary diagnosis, it seems the temperature thing trumps expansion.

 

[wakeup 19]

Thanks for your thoughts. I will try to get out on it tonight and see if I can tell if the marks are out of line after I run it and recreate issue. it is tough to see back there. maybe a mirror will help as well.
strange one!

 

[Lazy Daze]

Mirror on a stick (those expandable stick mirror thingies)... or even using your cell phone (pic or video). The advantage to the cell phone is it has it's own light. Just don't drop it! Good luck!

 

[wakeup 19]

Dennis, I figured out the issue last night. The outdrive is lifitng up. There is something wrong with the pump that is not holding it in place so it was cavitating. it would only happen if I went in reverse then forward or if I trimmed it up then tried to get back on plane. I went out with another set of eyes on my boat last night instead of the wife and we figured it our.
Now I need to get a new pump.
Last year my mechanic change the pistons and lines on that outdrive. in the spring i noticed one was leaking. It was loose so I tighten it and added fluid. I am thinking that water got into pump causing a problem. Not sure if draining it and and putting fresh fluid in will solve problem or I should just get a new pump.
thanks for your help.

 

[Lazy Daze]

That's actually really good news. You just saved yourself a bundle of money. As you might know, the only way to replace your coupler is to remove the engine.

Before you change anything, it might just be low on fluid. You're right that you could have water in there, but generally you'll be able to see that in the fluid at the pump (especially after using it for a while). Either way, I wouldn't condemn the pump "just because". Check the fluid out - fill the reservoir - even open the lines at the pistons and run the pump up/down while someone continues to add fluid. Catch the fluid in a glass jar (spaghetti) and let it settle. If there's water, you'll see it. If no water, tighten the lines and keep filling the reservoir while running the drive up/down to purge the system of air.

There's as much of a possibility that there's just air in the system as there is water. FYI, you can use STRAIGHT 30-weight motor oil in the pump (super inexpensive).

Oh, and always trim "down" when trying to get back on plane. Trimming up can lead to ventilation, along with increased 'time to plane'... which equals more stress on the engine/drivetrain and more fuel usage.

 

[wakeup 19]

yes i knew engine would have to come out for coupler. good news
The res was 3/4 filled then i topped it off last night and trimmed up and down a bunch of times. I used ATF and it was turning pink which is telling me there is some water in the system. Also, when i trim it down at the dock it does not come in solid and kind of thump if you know what I mean.
I have owned the boat for 10 plus years so yes I always trim down before starting but i think going 8mph and trimming was not working effectively. Last night I put it in nuetral then trimmed down. it is def not tight and looses trim with pressure.
I am going to pull it because a) i want to get the matching prop back on and b) I will do what you sugg and get all the old hydraulic fluid out and refill with 30 oil,
I will let you know how it works out. ARe there any specific seals that can be replaced on those?

 

[Bob & Sue]

This probably isn't your problem I have a Bravo 2 drive a couple years ago I topped off the the reservoir I had set the cap by the thermostat while filling it. For a couple weeks I noticed the up down felt different but everything looked good no leaks tank full I happened to set a flashlight by the thermostat when I noticed a gasket laying there it turned out to be the pump cap gasket put it back in the cap all was fine.

Not sure on Alphas if they are pressurized it may be a bad gasket or missing one, might be worth a look, on the Bravo the cap without gasket sealed enough not to have any leaks.

 

[wakeup 19]

This probably isn't your problem I have a Bravo 2 drive a couple years ago I topped off the the reservoir I had set the cap by the thermostat while filling it. For a couple weeks I noticed the up down felt different but everything looked good no leaks tank full I happened to set a flashlight by the thermostat when I noticed a gasket laying there it turned out to be the pump cap gasket put it back in the cap all was fine.

Not sure on Alphas if they are pressurized it may be a bad gasket or missing one, might be worth a look, on the Bravo the cap without gasket sealed enough not to have any leaks.

I trimmed up and down several times with cap off after i filled it to see it there were any air bubbles and make sure the level didn't go down. then I put cap back and went up and down again.
I think having the fluid leak out of the piston hose last season allowed some water into the system. Hopefully when i pull it and drain and refill the res. it will work better and not lift up without the button

 

[Lazy Daze]

It's air in the system that is causing the drive to move on it's own (lift up). Water is incompressible and while it's not "good" for the system, it's the cause of the drive moving. Of course, that's not to say that you don't ALSO have water in there. There's a chance that there's an internal failure of the piston that's causing the "thumping"... but it could also be caused by air so let's stick with that, for now, since it's the most likely explanation.

Basically, what you need to do is just totally flush the system. You should start with the "up" circuit, which is the hydraulic line that is closest to the boat (on the piston). Then the down circuit. Those are easy. The tricky part, and what will likely take some time, is flushing the actual piston. OH! As I'm typing, I just thought of something... google "oildyne trim pump" - that should get you a manual for your trim pump. In it, will be a section on air bleeding.

I'm not sure what having ATF in the system will do. Everything I've always read is to either use motor oil or Merc's power steering and trim fluid (but that stuff get's expensive to fill a whole system with).

 

[wakeup 19]

It's air in the system that is causing the drive to move on it's own (lift up). Water is incompressible and while it's not "good" for the system, it's the cause of the drive moving. Of course, that's not to say that you don't ALSO have water in there. There's a chance that there's an internal failure of the piston that's causing the "thumping"... but it could also be caused by air so let's stick with that, for now, since it's the most likely explanation.

Basically, what you need to do is just totally flush the system. You should start with the "up" circuit, which is the hydraulic line that is closest to the boat (on the piston). Then the down circuit. Those are easy. The tricky part, and what will likely take some time, is flushing the actual piston. OH! As I'm typing, I just thought of something... google "oildyne trim pump" - that should get you a manual for your trim pump. In it, will be a section on air bleeding.

I'm not sure what having ATF in the system will do. Everything I've always read is to either use motor oil or Merc's power steering and trim fluid (but that stuff get's expensive to fill a whole system with).

thanks, the "thumping is the good side. you know when you can feel the drive bottom out when trim is all the way down.
I am not getting that from the other side. I am using Power steering fluid, not ATF but I think switching to oil is a better idea as it is thicker.
I will also review bleeding prodcedures on the website you reference. Hopefully I can get her out tomorrow. We are a private YC so I can usually get her out pretty quick.

thanks

 

[Lazy Daze]

"Bottoming out" - OK, now I understand what you are referring to. I thought you meant the drive was thumping as it was raised/lowered - meaning, in the middle of it's "stroke". Yes, that all makes sense. If there's air in there, then the drive isn't being pulled down with enough force to make it thump. And that sounds good, as well, to more than likely eliminate an internal failure.

 

[Bob & Sue]

I'm not sure what having ATF in the system will do. Everything I've always read is to either use motor oil or Merc's power steering and trim fluid (but that stuff get's expensive to fill a whole system with).

I have been told Mercruiser used ATF in the 60's to early 70's but had problems and switched to Mercruiser Power Trim and Steering Fluid.

If you do use SAE 10W-30 or 10W-40 engine oil NEVER mix the 2 fluids unless it's an emergency, drain and refill the system and fill with whichever you feel is best. I prefer the Power Trim and Steering Fluid but that's just my preference.

I know Mercruiser doesn't make there own oils, fluids or anti freeze but I feel a few extra dollars in fluids is cheap compared to everything else we spend on these toys, I just paid $19.00 for a gallon of Mercruiser 50/50 extended life anti freeze when I could have bought Prestone ext life 50/50 for $12.24 from amazon prime.

 

[Lazy Daze]

I have been told Mercruiser used ATF in the 60's to early 70's but had problems and switched to Mercruiser Power Trim and Steering Fluid.

If you do use SAE 10W-30 or 10W-40 engine oil NEVER mix the 2 fluids unless it's an emergency, drain and refill the system and fill with whichever you feel is best. I prefer the Power Trim and Steering Fluid but that's just my preference.

I know Mercruiser doesn't make there own oils, fluids or anti freeze but I feel a few extra dollars in fluids is cheap compared to everything else we spend on these toys, I just paid $19.00 for a gallon of Mercruiser 50/50 extended life anti freeze when I could have bought Prestone ext life 50/50 for $12.24 from amazon prime.

I feel the same way. Not because of where I work, but I've always thought that unless I know more than the engineers (which I don't!) that spec'd what my engines need (additive packages, etc), I'll stick with their recommendation. I do the same for my cars. It's just not worth a few dollars once a year vs my piece of mind.

This could be my naivety showing in this subject, but I thought that ATF was designed to actually provide "Some" friction for clutches, etc, where motor oil would be slipperier? If that's true, then maybe that has something to do with the Merc recommendation to use motor oil, not ATF?

 

[BillK2632]

+1 on using the Merc oils/fluids. For the little amount I need it's not worth the couple f $$ I would save.

Back to the issue at hand - glad it is not the coupler!

 

[blaster]

I've read that ATF may swell and damage seals shortening their life in trim systems.
I also believe the use of detergent oil is not recommended in trim systems.