Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 16-04-2016, 14:25   #1
Registered User

Join Date: Nov 2014
Posts: 18
Engine Mounts

I have a Yanmar 3GM30F with a SD20 saildrive. I need to replace the two motor mounts on the engine and the rubber mount on the saildrive. Any advice on doing this would be greatly appreciated. I'm thinking I can replace the motor mounts one at a time, without disconnecting the saildrive, but am not sure if this is possible. Also, are there alignment issues like there are for shaft drives? Thank for your help!

cyphert is offline   Reply With Quote
Old 16-04-2016, 15:33   #2
Registered User
Sandero's Avatar

Join Date: Apr 2006
Location: Southern Westchester/Northport LI
Boat: Shiva - Contest 36s
Posts: 3,890
Re: Engine Mounts

Yes... do it one at a time... you likely will have to re align the motor to the shaft... Usually you release the bolts of the transmission to the prop shaft.. and re attach and align the plates of the coupling by raising or lowering the engine mounts or even moving them laterally. You align the engine to the prop shaft. Once all mounts are installed the plates must be perfectly parallel for alignment. When the are parallel.. torque the coupling bolts... and the engine mount vertical alignment nuts.

Re-torque all the nuts. Engine should run without vibration nor water from the shaft coupling or stuffing box.

Basically it goes something like this if there is no sail drive:

Purchase all the mounts you will be replacing. Verify that they are identical... and match the hole pattern.

Remove engine parts to gain access to the bolts and the engine brackets which the mounts are connected to.

Before removing ANYTHING take pics

Put wood blocking under the engine at the location of the mount you are replacing. Large footprint is better.

Remove the top nut on vertical adjustment bolt of the engine mount.

Measure the height and lateral location of the engine before removing the BRACKET to ENGINE BOLTS.

Loosen the bolts securing the bracket to the engine.

Lift the bracket off. Clean removed parts.

Remove the old engine mount - clean or paint the stringer as needed.

NOTE: you want to put the new mount as close to where the old one was in 3 axes if you can.

Bolt the NEW engine mount to Stringer.

Raise or lower bolt to the height of the bolt of the removed mount. You want the same height. If the mount has slotted holes for the bolts you use this for lateral (athwartship) alignment. Before torquing the mount to the stringer... bolt the bracket to the engine and position the engine mount so the vertical alignment bolt goes straight through the bracket when the bracket bolts are torqued down tight.

USE a PIPE to extend the wrench for leverage (torque). Once the bracket it torqued down AND the mount is aligned and the vertical alignment bolt plumb, and the lower bolt is raised right up to the bracket.... torque the bolts/nuts to the stringer.

Put the top nuts on the engine mount vertical alignment bolt. hand tighten. At this point all nuts are torqued except the top top nut of the vertical alignment bolt.

REPEAT the above for each mount.

Align the engine to the shaft by raising or lowering the engine mount nuts. When the coupling plates are parallel torque the bolts on the plate and then all the engine bracket and engine mount bolts.

Put all the parts back on the motor... belts etc...

Sandero is online now   Reply With Quote
Old 16-04-2016, 17:27   #3
Registered User

Join Date: Nov 2014
Posts: 18
Re: Engine Mounts

Thank for the great information. My one concern is that my engine setup is with a Yanmar SD 20 saildrive. Thus there is no shaft, stuffing box, cutlas bearing etc. What concerns, if any, does this pose in terms of alignment?
cyphert is offline   Reply With Quote
Old 16-04-2016, 19:23   #4
Senior Cruiser

Cruisers Forum Supporter

Join Date: Oct 2007
Location: virginia
Boat: islandpacket
Posts: 1,655
Re: Engine Mounts

Those motor mounts are incredibly expensive at $250 each.
Torensons marine has aftermarket ones at $50 each. You could change them all. I'm getting ready to sand blast mine if I cant get them cleaned up to please me, I'm going the aftermarket path. Best of luck
That derelict boat was another dream for somebody else, don't let it be your nightmare and a waste of your life.
Badsanta is offline   Reply With Quote


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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 Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Corroding Engine mounts ccannan Engines and Propulsion Systems 6 28-09-2015 23:13
After market engine mounts and polymer mounts Rustic Charm Engines and Propulsion Systems 32 10-03-2015 01:13
Need Engine Mounts and Instrument Panel Dream Maker Engines and Propulsion Systems 5 26-02-2014 13:12
Engine mounts; engine vibration on gear ErikFinn Engines and Propulsion Systems 18 07-03-2013 21:58
Engine mounts - When to replace? dkall Engines and Propulsion Systems 5 13-01-2007 03:49

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 05:19.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.