My universal joints went in my Bravo 1 last weekend, and i am in the process of replacing them, but the mercury ones are expensive compared to automtiv ones. Can i use auto u-joints? What makes u-joint go bad, my boat is a 1999 model with a 454 mag mpi with less then 100 hours. Is thier a better grade u-joint from merc then the factory replacements?
Thanks Bill

I believe that the automotive ones are not as good as the marine duty, I could be wrong on this, I buy mine from Boatfix.com for around $50 I think. I also change mine every other year. They take a lot of abuse and should be greased regularily. Was there any signs of rust on them? You may need to change the boot also. Make sure the alignment is dead on. The darn stock mounts have a habit of coming loose and dropping the front of the motor. This usually does in the gimbal bearing or u joints or coupler.

Several things contribute to u-joint failure.

1. Starting or running your motor with the drive up too far. I continually see people starting their motors at the ramp with the drive in the trailer position. It doesn't even sound good!!!!

2. Too much trim at cruising speed or higher.

3. No grease.

4. Misalligned drive. As stated above the front mounts tend to loosen up over time causing the drive to become missaglined. Re-allingment should be done at LEAST every spring. I do mine more often than that (often because I have had to pull the motor!!!)