Something slips in the driveline

[FreeBeeTony]

Re: Something slips in the driveline

It sounds like it has something to do with when the outdrive is turned. Is it possible the driveshaft is pulling out of the coupler when the outdrive is in a turned position? I would whink there would be alot of noise.........but who knows?<br /><br />And iI agree with cptkid.......could have used that same test on the prop.

 

[Rabbitdawghunter]

Re: Something slips in the driveline

Took it to the lake one more time, kept the bow trimmed all the way down until it plowed like a tractor in the turn. No slip. When I trimmed up any at all prop would blow out in every turn. The issue was apparently the prop the whole time. I did clean up the little bit of rough edge on the prop with a file before this outing. I have never had this small amount of roughness on the blades create a problem like this. Another tech that I talked to about this suggested going to a heavier cupped prop or a 4 blade to alleviate the problem. He also cautioned me to check the bottom of the boat for significant hook/rocker. I put a straight edge on the bottome and it was free of either condition. The stern is sound and the motor does not lift the bottom of the boat if if you pry under the front of the engine lightly to check the condition of the stringers. I am ordering a four blade prop. Maybe that will hold and this ordeal will be over with. Thanks for the input and assistance.

 

[olbuddyjack]

Re: Something slips in the driveline

Good call jlshields

 

[budman8330]

Re: Something slips in the driveline

is it the original motor and drive ?

 

[Rabbitdawghunter]

Re: Something slips in the driveline

Yes, all original equipment.

 

[KRS]

Re: Something slips in the driveline

So, 8 hours labor and $270 for a coupler... and that didn't fix it... now the customer is going to have to fork over more $$$ for a new prop just to see if that helps?<br /><br />I guess I'm a little surprised, I would be absolutely furious if a mechanic was guessing and replacing components until the problem went away rather than figuring it out and fixing it, or admitting they don't know and giving it back to me.<br /><br />I don't imagine that you did the coupler for free and you are opening up your wallet to buy the part. If I'm wrong, let me know.<br /><br />Not to beat up on you, but I can't see how it's allright to bill the customer for this stuff, when it's purely a guess and cross-your-fingers for luck type of thing?

 

[Rabbitdawghunter]

Re: Something slips in the driveline

Who says I'm billing for the prop? I just said I ordered one.

 

[HT32BSX115]

Re: Something slips in the driveline

I had a very similar problem with my 1966 150 Mercruiser. It acted like it was "jumping" out of gear.<br /><br />It finally acted like it wouldn't go into gear at all. I had to paddle back to the ramp!<br /><br />It turned out to be the coupler! ALL the splines were GONE!(in the coupler) The actual drive shaft was un-damaged.<br /><br />I would have NEVER expected the coupler to fail like that (of course, it was only 39 years old!)<br /><br />I expected the rubber "do-nut" to fail with smoke, smell etc. IT seemed like I could see in there but it was very hard to actually see anything wrong with it until I got it out. It seems like I could see enough with a mirror and a flashlight once I removed the out-drive.<br /><br />Of course I had to pull the engine to get at it.<br /><br /><br />Regards, <br /><br />Rick<br /><br /><br />

Originally posted by Rabbitdawghunter:<br /> I have been working on a 1987 3.0 liter Mercruiser with an Alpha One outdrive. I installed a new forward gear and clutchdog about 2 weeks ago. The owner came back with the boat claiming that it was still jumping out of gear. Lake test revealed that it was not jumping out of gear but rpms would go way up especially in a tight turn. The lower unit was still fully engaged in gear because it was still pushing the boat steadily about half speed. I'm suspecting the engine coupler is bad. I have removed the cap off of the upper drive housing and checked those gears. I have pulled the outdrive and inspected the driveshaft splines that go into the engine coupler and also the female splines of the engine coupler, they all looked good. I am just not seeing the smoke and the smell of rubber burning that I experienced with the last bad coupler I dealt with. Is there a way to isolate the coupler as the source of the problem without pulling the engine to get a look at the coupler?

 

[HT32BSX115]

Re: Something slips in the driveline

Maybe the outdrive is severely out of trim. It seems unlikely that a dinged prop could cause this.

 

[HT32BSX115]

Re: Something slips in the driveline

Sorry for the double post...I think I see what I did. I must have thought I was editing my own post and I clicked "quote" instead.

 

[waterone1@aol.com]

Re: Something slips in the driveline

Gee, I have never seen a coupler fail only while in a turn. Once they go, they go, the boat will not even get on plane. You MIGHT be able to run at idle with a blown coupler, but not get the boat on plane, at least without noise, smoke, etc. I have scratched my head many times on some strange problems, but never would have thought a boat that runs fine in a straight line would be a coupler problem when slipping in turns. Also have to say that a merc drive will not "slip" while in gear, it's either in gear or out and if popping out of gear I can't possibly described it as "slipping"....it will be jerking like he11.

 

[waterone1@aol.com]

Re: Something slips in the driveline

I have to agree with someone previous that questioned the prop thing. If the boat will run right in a straight line ( get quickly on plane with no slipping) then I am thinking not prop related. Look carefully at drive trim. Is it holding ? Run the boat hard in reverse, is the drive staying where it should or is it raising up ?

 

[Rabbitdawghunter]

Re: Something slips in the driveline

The four blade prop with more cup fixed the problem. Thanks to all who offered their advice.

 

[DHPMARINE]

Re: Something slips in the driveline

Uh Oh Now we have to wonder why a 1987 3.0L Alpha needs a 4 blade prop.<br /><br />All of a sudden.<br /><br />DHP

 

[Rabbitdawghunter]

Re: Something slips in the driveline

If you have something helpful to add I'm all ears. You know people come here to get help not become targets for cheap shots.

 

[Trent]

Re: Something slips in the driveline

Actually im with DHP.... Iv never heard of doing this... 3.0 with a four blade? Send a pic

 

[Don S]

Re: Something slips in the driveline

In the original post, I missed the part that it only happens when turning. Now if everything works fine except in a turn, and that same setup has been in there since 87, my guess is the hull design just allows the boat to "Lean" into the turn so far the prop comes out of the water.<br />This happens to lots of boats. The trick is is just not turning so tight so fast.<br />Not all boats are designed to make high speed turns.

 

[DHPMARINE]

Re: Something slips in the driveline

Sorry,I wasn't trying to take a cheap shop,just pointing out that the 4 blade is a bandaid,and a problem still exists.I,like you,would love to find the answer.<br /><br />DHP

 

[KRS]

Re: Something slips in the driveline

So, you aren't charging him for the prop, but the coupler (and labor for engine pull), new forward gear and clutchdog..... the fixes that never fixed the original problem, is that stuff billable?<br /><br />Not taking cheap shots, rather just asking a question. From an outsider (non-mechanic) it seems completely unethical to guess while using this guys money. So, if you are wrong does it come out of your pocket, or does he pay for it anyway? And if the boat comes back into the shop in 30 days for the same problem, are all of the original guessed repair costs absorbed by you?

 

[Rabbitdawghunter]

Re: Something slips in the driveline

I didn't charge for the coupler, ate it all. I did charge for the clutch dog and forward gear- I have the gears to show him and that did fix the jumps out of gear problem. I put a four blade prop on upon the advice of someone not on this board and it fixed the problem. It might not be textbook, but it fixed it. I could have just said F__ it like so many people would have and moved on to something else. I guess you get everything right the first time in your line of work?