Drive Shaft & Coupler

[interceptor212]

What causes the drive shaft to go out? I baby my boat and have had this happen for the second time in two years. I have put on approx. 30 hours since it happened same time last year. Never had any problems with my previous boat. Current boat has a 350 MAG with Bravo 1. I hope the mechanic I take it too honors the one year warranty he said he would give me. Any advice is appreciated.
[smilie=106.gif] [smilie=106.gif]

[meyerwrench]

Most of the time it is caused by the engine not being aligned properly with the drive.

[mnoutlaw]

I'm confused, our we taking about the coupler spinning out? If so, you could upgrade to the newer 496HO/500HP coupler and make sure it properly aligned and the motor mount are secure (front and rear). The newer coupler is stronger and has a longer spine shaft, it's a direct replacement with no other mods (merc part #861523A11).

[BajaLuvr]

I just replace my coupler... Most likely is the drive alignment. The mechanic told me that if you grease it every year and check the alignment that you shouldn't have problems. However, they had a new 38 Donzi spin the coupler (rubber around the spine) and it only had 10 hours on it (new).

They checked my port engine coupler and it was fine. So just the starboard was out of alignment... also replaced the engine mounts.

Big Thunder did the work on mine and they know what they are doing.... well atleast thats what they tell me [smilie=265.gif] :mrgreen: :mrgreen:

[Bajapit]

How many total hours are on your boat.
I had BTM check mine at 60 hours, But I don't know if they were off. Now have about 180 hours and still good.
LOTO is rough and It is a good Idea to stay on top of this.
twin 496 Mag Ho's...
PIT

[BajaLuvr]

They say trailering is the hardest thing on the alignment. I pulled mine back from Florida in February and didn't have it checked afterwards [smilie=050.gif] .

[tommynitro]

This is a VERY common problem, especially in 5-6 year old boats that havnt been greasesd and serviced every year. There are some minor preventative maintanance steps to prevent or at least prolong the coupler from spinning. Proper engine alignment is the most important thing and this is checked by pulling the drive off and sticking an alignment bar throught the transom plate and into the coupler. Adjustments to the motor mounts can bring the engine into proper alignment and then greasing the coupler splines at this point assures that the driveshaft is lubricated as it spins with the coupler. New boats are checked for engine alignment after the first 20 hrs and then I recommend every year in the fall afterwards to prevent premature coupler wear.

There are two different types of couplers, one is an aluminum hub that will wear out quicker and spin the internal splines and the longer wearing steel hub but it transfers more heat to the rubber part of the coupler and can cause the melting of the bond between the hub and the rubber allowing the hub to spin inside the rubber. All should be checked at least yearly and properly lubed.

Happy boating [smilie=042.gif]

[eddie]

I'm at 530 hours now and have towed serveral boats this year. I'm thinking about changing mine over winter so I don't have any down time. Is that crazy or what?

I guess if the motors out, no reason not to change the cam shaft, a little head work and give her some new parts? See that's why I can't pull it out until it breaks........ :roll:

[mnoutlaw]

Damn it Eddie! I'm going to have to run mine for 24 hours now to keep up! [smilie=106.gif]

Buy everything in threes so you can do mine also [smilie=265.gif]

[eddie]

Damn it Eddie! I'm going to have to run mine for 24 hours now to keep up! [smilie=106.gif]

Buy everything in threes so you can do mine also [smilie=265.gif]

Your going to get crushed this weekend anyway, you might as well give up. You can't keep up with my boating habbit. If I put in at 10 and get off the river at 9:00 each night as planned it's not going to look pretty on the hour meter. Then Labor Day I plan on doing the Sioux City run and thats a long haul......it's it snowing up there yet anyway? [smilie=265.gif]

If you would come clean with the 25 Outalw w/the 525 info I wouldn't have to worry about changing it [smilie=249.gif]