Removal/Installation Bow Thruster

recray

Active member
Joined
Feb 10, 2016
Messages
28
Fluid Motion Model
C-28
Hull Identification Number
FMLT2706E617
Vessel Name
Perfect Timing
Greetings,
I would like to know how to remove and install the bow thruster lower unit. I haven’t found a marine technician that is familiar with bow thrusters within 300 miles. I may perform the task myself. The lower unit is seeping oil and needs to go back to the factory for replacement (sealed unit at the factory). A new one is on the way. I’d appreciate assistance, comments or recommendations from anyone with experience in removal and installation of the Side-Power bow thruster lower unit. I will be contacting Imtra as well. Thanks.
Ray
‘17 R27
 
By "lower unit" what do you mean? The inboard part or the outboard part?
 
Outboard part of the thruster. The part in the tunnel where the prop is attached. The oil is seeping where the prop attaches to the shaft in the housing, lower unit. I have a pic but haven’t figured out how to post it.
 
That part is removed by taking off the mother from the inside and removing 2 hex bolts behind the motor. Comes tight off.


Stuart Bell
Ranger 25: Shearwater
(561) 352-1796
 
recray":4t9pcxkk said:
Outboard part of the thruster. The part in the tunnel where the prop is attached. The oil is seeping where the prop attaches to the shaft in the housing, lower unit. I have a pic but haven’t figured out how to post it.

Getting a User Photo Album for your Ranger Tug is easy but it requires submitting a request from within the site structure.

1. Sign on to the site, if you aren't already.

2. Select the User Control Panel link from the upper left corner of any page. Note: On the home page, this link is in your user menu in the upper right.

3. Click the Usergroups tab, then select the radio button next to the User Albums group.
Scroll down, choose "Join selected" in the drop-down menu, and click the Submit button.

Once you do this, an email is automatically sent to the administrator (me). That message will trigger my ability to approve your request, and you'll receive an email indicating your membership in the User Albums group has been activated.

I'll watch for the message, and look forward to seeing your pictures.

Cheers,

Bruce
 
There is a photo of the thruster drive leg in the Shearwater album on this site. Maybe it will help, but it was my rear thruster that had to be replaced - twice by Side Power and once by me when "right" became more important than "easy".

I also rewired the thrusters to use a 100A circuit breaker - each - and moved the thruster to the house battery, relocating one of the batteries to the forward locker under the bunk. Better thruster operation.

Discussed in Shearwater-sailing.com == look around

gallery2.php?g2_itemId=47598&g2_imageViewsIndex=1

http://www.tugnuts.com/gallery2.php?g2_itemId=47598&g2_imageViewsIndex=1/url]
 
Just replaced the bow thruster gearleg April 2018 on our R25SC. A fairly easy job. Most time consuming (but not too bad) is prep and painting of new gearleg and tunnel prep.
With prop removed and motor off - bolts out; try not to wiggle the old gearleg to get it out, just gently twist it until it releases from the caulk - it should be easy to get it out then. I wanted the tunnel shaft hole to stay as tight as possible.

Tape off the parts that do not get painted. Then coat with 2 part epoxy barrier coat (important if using copper bottom paint), then paint with bottom paint.
Install as 'dry run' before caulking - to make sure prop is free to spin.
Ranger recommended that I use caulk on both sides of the gasket - I used Sikaflex - liberally; using a scrap block of wood to keep the gearleg level when installing in tunnel (whole procedure is a one person job). Torque the bolts and wait few days or a week to paint the caulk and put the prop on.
 
Stop me if I'm getting too basic.
First you've got to get the front middle v-berth cushion out of the way. The other middle cushions will be needed to lay on while you work.

In the forward compartment, disconnect the two A/C insulated ducts from the front of the unit and move them to the side.

Remove the triangular panel that is screwed to the deck down there.
Scootch forward and you will see the forward part of the thruster motor.
It is connected to the thruster gear drive unit about 6-10 inches forward of what you can see.
Use your phone camera to get a photo of the area back there. It will help.
There are two allen screws (at 3 and 9 o'clock) that hold the motor to the gearunit at the tunnel.
I recall that it needs a 6 mm allen wrench. This is all done by feel. Take the two screws out and you can remove the motor. The motor unit contains the infamous shear pin that engages a slotted shaft on the gear unit. (Always an interesting task reinstalling.
(Unplug the wires and get the motor out of the way.)

I am trying to post some photos but they don't seem to be loading. Send me a message if they don't show up in my album. I can email the photos.

By removing the motor you expose a similar flange on the tunnel. This flange has the two hex head bolts that hold the gear unit in place. Now you can remove and replace the gear unit. ACTUALLY THEY ARE MORE ALLEN HEADS not HEX.

Reassembly is a bit of a trick. Get a couple bolts (i think 8mm x 1.25 that match the two allen bolts that you removed. Cut the heads off and clean up the threads. Install these two studs in the threaded holes. This makes it much easier to slide the motor back into place while you are struggling to align the shear pin with the slotted shaft. Once in, placing a nut on one of the studs might help (I forget). Remove the other stud and install the original allen screw. Then do the same on the other side. Snug both allen screws up and you've got it done.

Photos loaded ok on the second try. They will probably appear on my third page of photos.
 
I appreciate all your replies; most helpful...I’ll be posting progress and hopefully pictures as I proceed...
Ray
 
You did not say what year your Ranger was or if it had air conditioning. Some of the tugs have a split unit and the cooling coil is located above the thruster motor. You may have to remove the ductting to reach down to the motor and have access.
 
2017 R27 with A/C, however ducting is not an issue accessing the bow thruster...Thanks

ps please let me know if you can access the photo of the seeping bow thruster I posted on my photo album...
 
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