Bravo Coupler
 

Hi There

i have an 06 350 mag mpi/bravo one drive that stripped the stock a9 aluminum coupler splines in 100 hours (first 100 hrs on boat). I took the engine out and replaced the coupler with another aluminum a9. At that time i did NOT check the engine alignment like a dummy! So i ran the engine for another 100 hours and it was just in the back of my head of why those splines completely stripped and left me stranded. So i decided to replace the coupler with a steel a11 which should be major overkill and check the alignment. I do remember having to move the front mounts a bit to get the steel one aligned. Does this mean that the engine was probably out of alignment with the aluminum one installed? I installed the coupler with the tapered bolts per the merc bulletin. I set the alignment and checked it every 45 degrees of rotation. I can pull the bar out with two fingers except it was a tad harder in one spot about 30 degrees of rotation. Since it was so minimal i just threw the drive on and went. And it has a vibration at about plowing rpm but it is smooth once planed. It drives me nuts because the aluminum coupler never did that. So i did a warranty claim on the a11 coupler and recieved another one. I installed that and the same thing as far as a hard spot. So i yanked the engine out again last night and i am going to check runout this evening. I have also been so fed up with this heavy duty coupler i ordered an a9 aluminum. I also have another brand new a11. So a few questions here. First of all which coupler do you think i should install? And i will attach a few pictures of the aluminum coupler that i ran for a 100 hours before installing the steel one. All this work has been over a span of 3 years. I don't think i ever checked alignment with an aluminum coupler installed. Today i decided to grab that aluminum coupler that i had and look at it a bit closer. I noticed some excessive teeth wear on the end towards the flywheel. Do you think that wear was from being out of alignment? This coupler was waaaaay over greased because i was worried that the original coupler stripped because the first owner never greased it.

can't post pics, i'll find a way later this evening...

Thank you for your time!

Brian

I stripped the splines out of my coupler....engine out of alignment.

Ken

was yours aluminum?

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https://cimg7.ibsrv.net/gimg/www.off...81f441ebd5.jpg
https://cimg8.ibsrv.net/gimg/www.off...e0e55f6bbf.jpg

ok i think i'm going back to the aluminum coupler and hopefully with the engine aligned perfectly i won't have any trouble. My flywheel has .003 runout. I tested the runout of two new a11 couplers i had and a new aluminum a9. All centered using the tapered screws then torquing the new bolts to 35 ft lbs in the specific sequence. I put the dial indicator at the inside diameter near the splines. On the a11 it was on the inside diameter of the snout at the very outside so far away from the splines. Then i measured on the outside of the snout close to the rubber and got the same results. Both a11 couplers had around .030 and the aluminum is .009. So that means the coupler is .006 out of round if the flywheel is .003. Should i try to rotate the coupler or try to re center it to get closer to .003 or is .009 total runout just fine?