Go Back  Offshoreonly.com > Technical > Drives and Lower Units
Trying to figure out what happened today >

Trying to figure out what happened today

Notices

Trying to figure out what happened today

Thread Tools
 
Old 05-21-2016 | 11:55 PM
  #1  
hblair's Avatar
Thread Starter
Platinum Member
15 Year Member
Platinum Member
 
Joined: Oct 2006
Posts: 1,569
Likes: 1,671
Default Trying to figure out what happened today

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
hblair is offline  
Reply
Old 05-22-2016 | 01:38 AM
  #2  
Registered
 
Joined: Mar 2009
Posts: 1,758
Likes: 3
From: OFallon,Mo.
Default

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.
picklenjim is offline  
Reply
Old 05-22-2016 | 05:41 AM
  #3  
jeff32's Avatar
Registered
20 Year Member
 
Joined: Jun 2004
Posts: 8,218
Likes: 573
From: St-Hyacinthe, quebec, canada
Default

There is always a little something huh...
jeff32 is offline  
Reply
Old 05-22-2016 | 06:02 AM
  #4  
Registered
15 Year Member
 
Joined: Mar 2006
Posts: 432
Likes: 0
From: Lake George NY
Default

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
Clustergear is offline  
Reply
Old 05-22-2016 | 09:53 PM
  #5  
Tinkerer's Avatar
Registered
20 Year Member
 
Joined: Jan 2002
Posts: 4,612
Likes: 7
From: ALTO, MI
Default

Drive broke first then the U joint. Probably fixable.
Tinkerer is offline  
Reply
Old 05-22-2016 | 10:11 PM
  #6  
hblair's Avatar
Thread Starter
Platinum Member
15 Year Member
Platinum Member
 
Joined: Oct 2006
Posts: 1,569
Likes: 1,671
Default

I'll crack the lower open tomorrow. Where do you guys get gears? Are there any old stock new stuff laying around? Aftermarket?
hblair is offline  
Reply
Old 05-23-2016 | 12:24 AM
  #7  
Registered
 
Joined: Mar 2009
Posts: 1,758
Likes: 3
From: OFallon,Mo.
Default

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.
picklenjim is offline  
Reply
Old 05-24-2016 | 06:29 AM
  #8  
Registered
20 Year Member
 
Joined: Jul 2004
Posts: 11,332
Likes: 73
From: chicago
Default

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.

Last edited by MILD THUNDER; 05-24-2016 at 06:32 AM.
MILD THUNDER is offline  
Reply
Old 05-24-2016 | 12:13 PM
  #9  
Registered
15 Year Member
 
Joined: May 2010
Posts: 996
Likes: 189
From: Red Oak, Texas
Default

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?
CDShack is offline  
Reply
Old 05-26-2016 | 09:25 PM
  #10  
hblair's Avatar
Thread Starter
Platinum Member
15 Year Member
Platinum Member
 
Joined: Oct 2006
Posts: 1,569
Likes: 1,671
Default

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.
hblair is offline  
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.