Motors jammed, again!

After merging with Sofar, where can I find support for the Trident? My replacement motors got jammed, so I need a new set…

G’day allolas,

You can email or call them on +1 (415) 230-2299 to discuss replacement motors.

I have replaced a couple of motors so I am now very careful to make sure the motors in my Tridents are clean and dry after every dive. I have found that removing the rear motor covers and running all of the motors in fresh water for a couple of minutes before I leave the dive site helps. I then use a cotton rag and compressed air in a can to really dry the hull and motors well. apply a small amount of water dispersant spray such as WD-40 to the motor housings where they join the fixed part of the motors. I also check them every couple of weeks if I am not diving. Lastly, I put dessicant pouches in the hard cases if I need to store them for more than a month.

I can send you some more information including photos of where to apply the WD-40 if needed.

I’ve also torn them apart and sanded the magnets on the inner housing. I had a problem with corrosion under the brass fitting over the magnets and had to remove the whole thing. Lubricate them with grease. They require periodic maintenance. I’ve replaced them before, but corrosion will always be an issue so a periodic cleaning and re application of wd-40 or other grease is needed. Nothing can escape the ravages of the sea, nothing.


Hi Jim-N

Yes, me too. I apply light electronics grease and WD-40 to the inside of the motors on a regular basis.

If anyone else is wondering how to service their motors then I would be happy to describe what I have learned. There are a couple of things to watch out for however the motors can be opened quickly and easily…the rear motors can even be serviced without removing their electrical connectors.

I am interested in this procedure (cover removal without disconnecting the motors)

Thanks -

G’day Scott,

How “handy” are you at tinkering with things?

The process of inspecting and maintaining the internal motor compartment is simple enough if you have already replaced the motors before and if you are confident using small tools and handling small parts.

The trickiest part is looking for and preserving the tiny shims that may have been used to assemble the motors…and not losing the circlips that hold the motors together.

I will provide additional information and a couple photos when I get home tonight.

Kind regards

If you have not already replaced your motors, I recommend that you find and download the instructions on how to remove and replace your motors and then watch the video. These resources will provide you with everything you need to know about the tools required and the basic methods for removing the motors. You will be following some of the same steps to remove your motors but not all of them. In particular, you will NOT be removing the electrical connectors.

After removing the aft motor wet bay covers, look for and remove the motor screw connectors and then pry the aft motors away from their mounts. The aft motors and propellers can then be carefully lifted and rotated around inside the wet bay in a way that gives you access to the circlips (the small stainless steel clips that are pressed onto the rear of the motor shaft). The circlip is annotated with a blue arrow in the aft motor photo.

The circlip is also annotated as number 1 in the expanded photo of the vertical motor as an example. Please note the propeller has been removed from the vertical motor in this photo (you may choose to do the same).

Use a pair of needle nose pliers (or a metal skewer) to gently push the circlip off the shaft. It will only come off in one direction. It does not take much force and they move quite easily but TAKE CARE!!!. The clips may spring away and be lost forever.

After removing the circlip, and depending on how much corrosion you have inside the motor, the outer housing can be quite easily pulled away from the black base with your fingers. This may be difficult and next to impossible if the motors are corroded. As a rule of thumb, if the motors turn freely by hand then you should be able to soak them in water or WD-40 to help get them apart. Take care to avoid damaging the white plastic washer if you feel the need to pry the motor housing away from the base. Be patient…give the motor lots of movement whilst pulling it apart it will eventually come apart. Keep the white washer. A shim is annotated as number 2 in the expanded photo of the vertical motor and the white washer is annotated as number three as an example.

Take care when separating the outer housing from the base because some motors have one or two shims located on the shaft. I recommend you disassemble the motors over a large flat work area and check for shims as you go. They may sometimes fall off the shaft and onto the work surface or they may sometimes remain captive on the shaft. Make sure you look for them and note where they come from.

Once the outer housing has been removed, it can be inspected for corrosion and cleaned with water and then a suitable parts cleaner. I use a soft cotton cloth and cotton tips. This is sometimes the first time that you find the shims. When the internal surfaces are clean they can be treated with a thin film of silicone grease (or WD-40 or other similar corrosion inhibitor).

The green coloured windings may also be covered in salt, silt or other corrosion products. Give it a clean and then a light coating of corrosion inhibitor.

The motor can then be reassembled. Take care to replace the shims and the white plastic washer. The motor will “snap” together magnetically as you close it up so take care. The last step is to replace the circlip by gently pressing it back onto the shaft. If the circlip feels a bit loose and keeps falling off then the arms can be VERY carefully pressed a LITTLE bit closer together with a good pair of pliers. TAKE CARE!!! The circlip will almost certainly be lost forever if it springs out of the pliers.

Finally, twist the motor back around and press it back under the motor mount. Clean the screw connectors and apply a drop of low strength locking compound to their tips. Reconnect the motors and replace the wet bay covers.

The vertical motor is very similar. Remove the two screw connectors (annotated as number 1) from the ends of the plastic cover plate. The motor can then be lifted away from the tunnel. Remove the two inner screw connectors (annotated as number 2) and then set the plastic cover plate aside. It is likely to be full of silt and sand so give it a good clean. Make sure to identify which screws come from each hole because they are different.

You will now see the circlip that holds the motor together. Remove this circlip and set it aside with the same precautions as before.

The motor should then separate in the same way as the aft motors. You can replace the two inner screws to provide something for you to hold onto if needed to help separate the motor. Once again, keep your eye out for shims and keep the white plastic washer.

Reassemble in a similar way to the aft motors and then reinstall the motor based on the motor replacement guide. Use low strength locking compound when replacing the screw connectors.

All going well, you should now feel comfortable knowing that your motors are OK and that they now run a bit better. Alternatively, you might now realise that you need some new motors.

I hope this helps.

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GREAT work if the inside of your motor looks like this (note the shim and the circlip).

You had better contact the guys at support if your motor looks like the one below…(note the squashed and broken white plastic washer and the brute force needed to separate the housing that caused the housing to separate hahaha). This was one of the earlier motors and it was not very well rinsed.

Jason…extremely helpful. Thanks for taking the time to upload these executable instructions to the forum. Is this a procedure you go through post dive (after every session?)

I don’t do it for every dive but I do it on a regular basis. I have a post dive checklist that I follow…but I will have to reply with these details later…I now need to get some rest for tomorrow (I live in Brisbane, Australia and my computer just turned into a pumpkin).

Here are some more photos of the “part” motor removal process. The first one shows what the aft motors will look like after you remove the connector screws and then lift and rotate the motor within the wet bay.

The next one shows what the vertical motor will look like if you operate in fine sand like I do.

The last one shows some corrosion inside a vertical motor without the brass covers.

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Thanks for the infomation,
I have a Trident and the motors are stuck, I managed to disassemble one and it has a bad bearing, do you know where you can buy bearings or how you can change these bearings? Has anyone done it? or where can you buy motors that can be installed on the trident?


G’day Reinaldo,

If you don’t have a set of Vernier’s you should be able to take the motors to a local bearing supplier who will be able to measure and provide a replacement specification. I will measure my bearings and shafts over the weekend and post the dimensions.

You should be able to clean the shafts with a piece of Scotch Bright pad and/or emery paper if they are not too badly corroded. Are you able to send photos of your motors and in particular the corrosion on the shaft?

Kind regards

I live on Easter Island (3500Km from Chile, in midle of Pacific) so there is no local supplier, I would like to know the size before taking them out so I can order them …, for this razon, I asked if someone knew the mesurement or had taken out these bearings.

It is not the axle that is worn but the “axle seat”, the edge where the axle fits into the housing.

The inner part of the outer rotor was polished with sandpaper and the help of a syringe to allow the rotor to rotate without touching the stator.

During the disassembly process (it was very tight) the Teflon seal was damaged, but with the help of a marine technician we made one with a similar thickness plastic and it worked well for the first test.
As a recommendation, the rov must be placed in fresh water and the motors must be activated so that the salty water is dislodged from the inside of the motors. and after each dive they should be disassembled, disassembled, washed with fresh water, dried and applied something like wd40 before storing

bearings work but feel gritty I need to change them I want to try Teflos bushings

Thank you so much

G’day Reinaldo,

Thanks for those photos, they are worth more than 1000 words.

The bearings in my Tridents are not marked and I have been unable to remove any of them from my new motors so I will hit one of my scrap motors with a bit of heat to help force the bearing out (I seem to have lost my graduated Lupe so I am unable to view and measure them under magnification except via my phone’s camera which is difficult).

Based on the best Vernier measurements I can take with the bearings still in the motor, the bearings appear very similar to NSK 4 x 10 or perhaps 4 x 9 shielded bearings as shown on page B34 of the PDF file at the end of the link. In any case I will try again tonight to see if I can get a specification. So long as the ID for the shaft is 4mm (this was an easy dimension to take), the OD can be ‘corrected’ with goop if it is a bit under-size.

Also, if you are happy to tinker, you may find it cheaper to order/fabricate some Teflon bearings with an ID of 4mm and an OD of 10mm with a thickness of 4mm. Press them tightly into the housing with a bit of goop if needed. I might even give this a try myself. If these turn out to be under or over size you can then try again to achieve the right combination of tight press-fit and low friction on the shaft.

In relation to your ‘axle seat’ do you know if any of your motors had one of those tiny shims fitted to them? These shims would be very difficult to notice if you had serious corrosion and you may have lost/destroyed it during cleaning.

G’day Reinaldo,

I have had some success. The bearings in my destroyed motor popped out easily with the right size punch…I was being too careful with my new motors. The bearings appear to be 4 x 9mm shielded bearings.

I assume the bearings are the same size across all series of motors so I hope this helps.

Hello thanks for the information,
I have measured (without removing the bearings) and I have the same measurements 4 and 9 mm.
I will send to make Teflon bushings they are not expensive and I think I can adjust them if necessary.
In relation to the shims, I did not find any, it seemed very strange to me but I did not find them.
I was careful during the dismantling and cleaning process not to find them, I don’t think they have corroded so much that I didn’t find a part of them.
If necessary I will make some with Teflon.but it will be slow, now we don’t have flights to the island.


You are welcome Reinaldo.

Not all motors require shims. If your motor spins freely without too much friction against the plastic washer when under load and if there is no excessive play in the housing then a shim is not needed. Several of my motors do not have shims and several of them have two shims. This is typical manufacturing practice.

If you need to replace a shim, give some sheet plastic a try…perhaps even some hard packaging plastic from consumer items. Use a leather hole punch to achieve a tight 4mm ID for the shaft and trim the OD as best as you can (this dimension is not so critical).

Yes the vernier caliper measurements are accurate and I understand the issue as I faced the same problem. I took assistance from Siemens repair center and resolved my problem.

Thank you for this thread. This gives me some hope I may be able to fix my broken trident.