The curse continues... Brand new coupler slipping?
09-25-2016, 11:31 AM
#13
Mark the coupler and shaft with a white paint stick then run and see if it's moved, do same with prop and hub. If neither have moved it's your drive/cone clutch.
Is there anything in front of the prop that may be causing cavitatiin?
Is there anything in front of the prop that may be causing cavitatiin?
09-25-2016, 02:38 PM
#17
Platinum Member
Platinum MemberThread Starter
iTrader: (2)
Here's my thinking on this:
I went with an aftermarket coupler (Sierra 18-2412). It was close in price to the OEM HD coupler offered by CP Performance, and was listed as a replacement part for an HP 500 (saw some guys here on OSO using this coupler with high HP and no issues). I would have gone with the OEM but CP wanted a lot of money to ship, and I got free shipping through Amazon. I didn't want to use the coupler with the grease shaft because I didn't have the room to get it installed. Anyway, potential lesson learned. I don't think the coupler was up to the task or it was defective.
The engine was aligned properly. The reason the last coupler failed was my fault. I was really sick putting the engine back in the boat after I had flywheel issues., and one of the spiral washers fell out when we were setting her back down. I didn't check alignment because it was good before. I was so sick during the whole install, and it was 98 degrees at 11 am... I just sssumed it was okay. Anyway, it stripped the splines out of the coupler. It was worn out anyway, and I put the last nail in its coffin. But I know for sure the alignment this time was spot on. And the transom, stringers, etc, are and were all perfect. And, I had ten hours on it with no issues until a backfire took out the starter/flywheel.
I'll order a new coupler and go through the whole process once again.
Any one seen a coupler with the rubber twisted like that? Is 650 lbs ft of torque enough to do that?
I went with an aftermarket coupler (Sierra 18-2412). It was close in price to the OEM HD coupler offered by CP Performance, and was listed as a replacement part for an HP 500 (saw some guys here on OSO using this coupler with high HP and no issues). I would have gone with the OEM but CP wanted a lot of money to ship, and I got free shipping through Amazon. I didn't want to use the coupler with the grease shaft because I didn't have the room to get it installed. Anyway, potential lesson learned. I don't think the coupler was up to the task or it was defective.
The engine was aligned properly. The reason the last coupler failed was my fault. I was really sick putting the engine back in the boat after I had flywheel issues., and one of the spiral washers fell out when we were setting her back down. I didn't check alignment because it was good before. I was so sick during the whole install, and it was 98 degrees at 11 am... I just sssumed it was okay. Anyway, it stripped the splines out of the coupler. It was worn out anyway, and I put the last nail in its coffin. But I know for sure the alignment this time was spot on. And the transom, stringers, etc, are and were all perfect. And, I had ten hours on it with no issues until a backfire took out the starter/flywheel.
I'll order a new coupler and go through the whole process once again.
Any one seen a coupler with the rubber twisted like that? Is 650 lbs ft of torque enough to do that?
09-25-2016, 03:06 PM
#19
Banned
iTrader: (9)
About half the time, it is best to buy the OEM parts because buying cheaper parts never works out being cheaper for the end results. CHINA crap. Also there is no quality checks on a lot of aftermarket parts. NONE especially for the marine side of things. Not trashing Sierra because some of there stuff is good and some of there is complete junk.
The number 1 problem with trashing a coupler in very short order when everything else is in 100 percent order - read the SB completely to make sure you are correct with the set you have. Also we have seen some Sierra couplers not holding up.
read this to a Tee. And even applies if your engine alignment is dead on -
http://www.marinemechanic.com/merc/d...her-design.pdf
Also make sure the person installing the coupler did not warp it. More common than you think. Also Merc has a SB that helps installing the coupler properly and this also helps with alignment. Highly recommend a OEM service manual that is specific to all your boat / engine / drive applications. This will give you proper procedures and correct torque specs along with correct part installs.
The number 1 problem with trashing a coupler in very short order when everything else is in 100 percent order - read the SB completely to make sure you are correct with the set you have. Also we have seen some Sierra couplers not holding up.
read this to a Tee. And even applies if your engine alignment is dead on -
http://www.marinemechanic.com/merc/d...her-design.pdf
Also make sure the person installing the coupler did not warp it. More common than you think. Also Merc has a SB that helps installing the coupler properly and this also helps with alignment. Highly recommend a OEM service manual that is specific to all your boat / engine / drive applications. This will give you proper procedures and correct torque specs along with correct part installs.
Last edited by BUP; 09-26-2016 at 12:22 AM.
