VP DP-SM Trim Sender and cylinder replacement

GeorgeDes

Petty Officer 2nd Class
Joined
Sep 30, 2013
Messages
107
Two questions regarding the VP DP-SM trim setup. I need to replace a sender on the outdrive unit. The PO cut the line where it exits the transom. I suspect he did so because it appears to be a real bear to feed a new line through the transom into the wngine bay and he probably just decided to forgo having one. There apparently is a metal clip that holds the send grommet from the inside of the transom and if this can be removed the line can be pulled out from the outdrive side and a replacement pulled back through using the original as a “snake”. The problem is that darn clip is totally hidden by the inside transom mount. Has anyone figured out a good way to reach and remove that clip without removing the engine? I realize it will be next to impossible to replace it and would opt to use some sealant to fix the replacement in place. The other question involves trim cylinder replacement. Does the system need to be depressurized before removing the lines and if so what is the correct procedure for doing so?
 

muc

"Retired" Association of Marine Technicians...
Joined
Jul 7, 2004
Messages
2,064
Heresy Sacrilege

I’ll let you in on a secret.
Most professional marine mechanics will deny that we do this.
We don’t put that clip back on.

Here is how most of us do it.

Cut the wires as close to the grommet as possible.
Take a #2 Phillips screwdriver about 14” to 18” long and grind the tip flat, now put a couple of bends in the shaft so from the outside of the boat you can use it to push the grommet into the inside of the boat.
Clean the hole with brake cleaner.
Feed the new sender wires into the boat until the until the grommet is almost to the hole.
Get somebody to help you in the boat and have them grab the wires so they can pull them in a straight line.
Spray the grommet and hole with a good shot of brake clean. No sealant, it will lock in place.
Have your helper slowly pull on the wires while you watch for the grommet to seat against the transom shield.
Yell stop when it seats.
If your really worried it might fall out, zip tie the wires to the water intake hose.


Trim the cylinders all the way in/down and then do a quick tap of the up/out button. Disconnect the cylinders from the drive so there isn’t any weight on them.
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,798
I read of people who can actually reach that clip, tying a bit of string to it, long enough to tie onto a wiring harness or similar. That way if you pop the clip off it will not disappear forever into the recesses of the bilge.

This way done by my OMC mechanic was even more heretical. OMC Cobra used a similar difficult to replace sending unit in fact Volvo adopted this.
What he did:
Just drilled a hole in the side of the transom mount, cut the terminals off the sending unit wires. Put a grommet in the hole in the transom mount, ran the wire thought the grommet/hole and left enough slack in the wires to allow the drive to turn left and right. Then run those wires up the transom and inside, just the same way you'd do with a transducer mount. I have been able to change these sending units very easily on this boat, in about 10 min. Inside I used bullet terminals on the original wiring harness and just crimp the other end on the wiring from the sender. Not orthodox but very easy and has worked fine over 10 years!
PS, the plug in mine, does have the clip installed lol! That worried me a bit.
 

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GeorgeDes

Petty Officer 2nd Class
Joined
Sep 30, 2013
Messages
107
Thanks. Sounds like the screwdriver trick cutting and pulling the grommet through is the best way to go. Whoever designed that setup with the hidden clip deserves to be shot!
 

dypcdiver

Lieutenant Junior Grade
Joined
Nov 1, 2005
Messages
1,016
I have done this job 6 times. I can just reach the little clip and always tie some light line to it. The cable has a connector on the inboard of the transom, if you disconnect it there and then tie an overhand knot as close to the rubber plug that you have just removed the clip from, then go to the outboard side of the transom shield it is easy to pull the wire and the plug will pop out when the knot butts up to it. If you don't tie a knot, the cable will pull right through without dislodging the rubber plug. Don't ask how I know!

I have a large nail that I ground the end 3/4 of an inch down on, that I use to push the connectors out of the rubber connector inside the transom.

Job is much easier if you remove the gimbal housing, so you can see what you are doing better.

The quality of the senders has improved I have had this last one in for 6 seasons but it now needs replacing . Previous ones seldom lasted 2 seasons and they are not cheap.
 
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wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
Most of the ones that I've replaced were because muskrats had lunched on the wiring.
I've managed to remove and reinstall the clip but as I mentioned previously, I've had to strip everything from the starboard side of the engine compartment.
Still, being a contortionist would help.
 
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