hblair

Twin 489's, TRS drives. We were out for a ride today about 3,000rpm. All of a sudden I get a high pitch grinding noise. I shut down the motors. Put them in neutral. I go swimming and check the props. Didn't hit anything. Turn the props, port side sounds normal, right side makes a noise and gives some resistance. I cripple back to the ramp on the port motor. At the ramp we notice the right side is pouring fluid on the ramp and bellows is torn and the u joint basically falls out.
When I get to the shop we go ahead and pull the right drive. Here's what we find...




The u joint is trashed, but the drive gears will "jam up" after a few turns. I pulled the lower off and here is what it does...

https://youtu.be/j0rBIw7aixk

I'm thinking the lower gears locked up and destroyed the u joint? Does this sound right to you guys? Irregardless I plan to replace the whole thing including the transom plate. (I hate pulling the starboard engine)

Thoughts? Anybody got a drive laying around?
Thanks

picklenjim

I'm thinking it's more like the u-joint let go and caused damage in the lower. I don't know why you would think the lower gears locked up. They seem to be turning fine in the video though obviously there is something wrong in there. Gonna have to open up that lower and see what's going on.

jeff32

There is always a little something huh...

Clustergear

Watched video Sounds like a Tooth broke broke off one of the gears. When it broke, it most likely jammed lower and joint or yoke let loose

Tinkerer

Drive broke first then the U joint. Probably fixable.

hblair

I'll crack the lower open tomorrow. Where do you guys get gears? Are there any old stock new stuff laying around? Aftermarket?

picklenjim

New gears are still available. They run $6-700 for the set. I use this place. https://www.perfprotech.com/mercury-.../70?model=4340

I do have a used set of gears in great shape as well as a completely rebuilt lower with a hydramotive nose cone on it. Never been installed. If interested PM me.

MILD THUNDER

iTrader: (3)

You broke a lower gear . Very common on the RH rotation TRS lower. I've been there.

A buddy of mine had the same thing happen. Lower gear broke, jammed up, and actually blew his damper/drive plate apart, which shot a spring out, and put a hole in the bellhousing.

Looks like you have the "merc trans"? if your 489s are healthy builds, you may want to consider upgrading to 72c velvet drives.

CDShack

Sorry to hear! I know you worked hard getting that dude ready! Change one thing, ten things change (or break).
Has anyone done any research on what's wrong with boaters?

hblair

Well I got the parts here. Pickelnjim sold me a lower drive and u joint yoke Assy. Parts look good Jim. Thanks. I got a couple of gimbal assys from a guy on the Facebook parts swap. Now I just need some time to get it done. I also have to weld a skeg on the left drive. I broke it off the weekend before. That was just a mild disaster I didn't bother reporting here lol. There's definetly something wrong with us boaters. Me anyway.

Mild thunder I'm just trying to get this boat going so I can work on the other boat. The blowers aren't putting out hardly any boost. I plan on putting them in the '38. I'll prolly lower the compression, different heads and cams, and turn up the boost when I put them in the other boat and have them in front of the arnesons.