Is there anything available or better than the original Merc coupler for a B1 set up? I have low hours on mine and its already junk. The splines still look new but the outer flange that bolts to the flywheel is cracked and ready to break at every bolt hole.

I have had good success with Mercs steel hub coupler. The splines are steel and extend out past the rubber coupler a few inches.

we really run the hell out of them and even with big power with VERY few problems...i do not have all the facts but chances are you have other contributing issues resulting in that failure.

When you say big power..........how much power are you running? I am pushing 900hp and 800ft/tq. Thanks for your help.

I dont have that much power. I have 680 hp, 660 torque.

not that much...but your failure is to due to a resonance frequency...chances are on the engine side of that coupler...the coupler itself will fail from a over load/torque condition.

i know IMCO makes an aftermarket bellhousing but not sure on the coupler? give them a call.

I have never seen that happen before, The only thing that I can think of that might cause that would be the outdrive being out of alinment or maybe a loose engine mount

Make sure you have the right bolts for that coupler, the bolts have a shoulder, if not the coupler will move. The new coupler will come with the right bolts.

Bill........I think your on to something there. I looked at the bolts and they do not have shoulders. They are ARP flywheel blots.

861523A11 is the part number for the coupler with the steel hub.