2008 DF90A Tilt and Trim Issue (PTT)

[Ish1978]

Greetings all. I have a very low time (150ish hours) 2008 DF90A which developed a tilt issue a few months ago. Initially it basically just sounded like the motor was getting low voltage for the last 1/3 to 1/2 of the travel in the up direction. Going down was generally ok. The batteries are putting out around 12.7 volts on their own and over 14 volts with the engine running. so I ruled out a battery issue. I lived with it for a while and then it started to get slightly worse especially on the last maybe 1/5 of travel going up where the PTT motor really started to struggle. Once trimmed all the way up and the trim switch released, the trim motor would not operate but the PTT relay could clearly be heard clicking. After about 5-10 second, then power would come back to the motor and it would operate perfectly all the way down and sometimes up as well (all the way). Occasionally the motor would stop mid range and last week completely stopped and would not come back to life. I have measured full battery voltage at the PTT relay connector no matter what's happened when either trim switch is pressed up/down. When the motor isn't working, there an open circuit when measuring through the motor wires from the PTT relay. I pulled off the electric motor from the pump assy, turned the drive shaft of the electric motor and then it seemed to work perfectly in both directions and I got continuity through the motor wires again. I pulled the motor apart and performed all tests (180 degree commutator bar check, neighboring commutator bar check, checked for shorts between commutator and core/shaft, commutator diameter, and brush lengths) as stated in the engine service manual and all were perfect and even. The only thing I noticed was quite a bit of blacking on the commutator where the brushes rub. This I cleaned to shiny copper using 400 grit emery cloth. Putting my meter on the two inputs on the brush housing with the armature installed gave constant un-interrupted continuity even while spinning the armature in either direction. I did notice though that as soon as I mated the brush holder plate to the field case (bell housing with permanent magnets) then I would get constant continuity while spinning the drive shaft to the left but it would pulse going to the right. Everything looks perfect inside the field case which now chafing so I don't for the life of me understand why this is happening. I took it apart and reassembled multiple times with the same result. The motor seems to spin fine electrically not mated to the pump. After I mated to the pump and tried to drive the tilt piston down (not connected to the engine), it seemed to struggle and sounded quite rough. I tried to drive the piston up enough to insert the the upper pin to the engine but it wouldn't make it and the motor stopped again. PTT relay still clicking away, full battery voltage from the relay and no continuity through the motor. As soon as I popped the brush holder off, I would get continuity through the motor again. I popped off the brush holder and I noticed that the commutator was black again after only having run the motor for no more than 90 seconds from when I cleaned it all up. I've checked the hydraulic fluid level and it's fine and there is no other damage or leaks apparent from the outside. I'm at a loss as to where to take it from here. I can't explain what's going on with the electric motor and am not sure if i should buy a replacement. Or, is there something going on with the hydraulic side which is making the motor work too hard (why the blackened commutator after 90 seconds, or is this normal from the carbon brushes?)? Full disclosure here, I did back the boat on trailer up a small dirt driveway with the engine mostly down and it bent the skeg by about an inch and ruined the prop. Maybe this put excessive force on some of the internal hydraulic components? The exposed section of the hydraulic ram looks dead straight. I know it's meant to take an impact but only in the forward direction and not going backwards. I honestly don't recall if this issue started before or after that incident. I know this is very long winded but any help or other ideas would be most appreciated. As we all know, these components are quite expensive so I obviously don't want to purchase anything without knowing for sure what's going on first. Thanks!

[tsturm]

Were it me I would clean up the commutator bars on the armature with some fine (320 - 400) emery paper & blow out all the shineola & put it back together.

[Ish1978]

Thanks for the feed back tsrurm. I did that as one of my first steps. I cleaned the commutator bars with 400 grit emery cloth, cleaned out all the brush dust from everywhere, did all the resistance measurements and everything checked out fine. I still can't explain that with the whole motor assembled together - turning the drive shaft counterclockwise it has perfect continuity on the motor leads but turning clockwise it pulses about 20 times per revolution. If you remove the field case (permanent magnet housing), its perfect in both directions even while pushing the armature side to side / up and down.

[tsturm]

Oop's I only looked at the first pict, any copper smeared over between the bars? field magnet cracked? throw it out & get a new one.?? Clean the burr's off the brushes? strech the springs a little?
Good luck & have a good one

[Moonlighter]

Sometimes cleaning out trim motors works, for a while. Other times, a replacement is needed. Just seen this on a mate’s 140A.

[redlowrey]

Greetings all. I have a very low time (150ish hours) 2008 DF90A which developed a tilt issue a few months ago. Initially it basically just sounded like the motor was getting low voltage for the last 1/3 to 1/2 of the travel in the up direction. Going down was generally ok. The batteries are putting out around 12.7 volts on their own and over 14 volts with the engine running. so I ruled out a battery issue. I lived with it for a while and then it started to get slightly worse especially on the last maybe 1/5 of travel going up where the PTT motor really started to struggle. Once trimmed all the way up and the trim switch released, the trim motor would not operate but the PTT relay could clearly be heard clicking. After about 5-10 second, then power would come back to the motor and it would operate perfectly all the way down and sometimes up as well (all the way). Occasionally the motor would stop mid range and last week completely stopped and would not come back to life. I have measured full battery voltage at the PTT relay connector no matter what's happened when either trim switch is pressed up/down. When the motor isn't working, there an open circuit when measuring through the motor wires from the PTT relay. I pulled off the electric motor from the pump assy, turned the drive shaft of the electric motor and then it seemed to work perfectly in both directions and I got continuity through the motor wires again. I pulled the motor apart and performed all tests (180 degree commutator bar check, neighboring commutator bar check, checked for shorts between commutator and core/shaft, commutator diameter, and brush lengths) as stated in the engine service manual and all were perfect and even. The only thing I noticed was quite a bit of blacking on the commutator where the brushes rub. This I cleaned to shiny copper using 400 grit emery cloth. Putting my meter on the two inputs on the brush housing with the armature installed gave constant un-interrupted continuity even while spinning the armature in either direction. I did notice though that as soon as I mated the brush holder plate to the field case (bell housing with permanent magnets) then I would get constant continuity while spinning the drive shaft to the left but it would pulse going to the right. Everything looks perfect inside the field case which now chafing so I don't for the life of me understand why this is happening. I took it apart and reassembled multiple times with the same result. The motor seems to spin fine electrically not mated to the pump. After I mated to the pump and tried to drive the tilt piston down (not connected to the engine), it seemed to struggle and sounded quite rough. I tried to drive the piston up enough to insert the the upper pin to the engine but it wouldn't make it and the motor stopped again. PTT relay still clicking away, full battery voltage from the relay and no continuity through the motor. As soon as I popped the brush holder off, I would get continuity through the motor again. I popped off the brush holder and I noticed that the commutator was black again after only having run the motor for no more than 90 seconds from when I cleaned it all up. I've checked the hydraulic fluid level and it's fine and there is no other damage or leaks apparent from the outside. I'm at a loss as to where to take it from here. I can't explain what's going on with the electric motor and am not sure if i should buy a replacement. Or, is there something going on with the hydraulic side which is making the motor work too hard (why the blackened commutator after 90 seconds, or is this normal from the carbon brushes?)? Full disclosure here, I did back the boat on trailer up a small dirt driveway with the engine mostly down and it bent the skeg by about an inch and ruined the prop. Maybe this put excessive force on some of the internal hydraulic components? The exposed section of the hydraulic ram looks dead straight. I know it's meant to take an impact but only in the forward direction and not going backwards. I honestly don't recall if this issue started before or after that incident. I know this is very long winded but any help or other ideas would be most appreciated. As we all know, these components are quite expensive so I obviously don't want to purchase anything without knowing for sure what's going on first. Thanks!

Three things to check, the battery voltage under load, connect up an amp meter and check how much draw when under load, and remember when you spin the armature by hand it is not a motor, you are inducing a voltage through a magnetic field, it will generate a voltage. Spinning it on ohm is no good because the meter is sending out a voltage and the armature is creating a voltage.
Put your meter on milli volts and spin, don't condemn it yet, see how much current it is drawing you might have a problem in the hydraulics.

[Ish1978]

Thanks for the comments redlowrey, and great point regarding the resistance through an assembled motor. The one thing I'm struggling with is that during the original problem, the motor would slow down near the top of the piston stroke and then stop completely with either an up/down switch selection. The PTT relay could be heard clicking and full battery voltage measured coming out of the relay. When measuring resistance through the stationary motor, it would be completely open circuit. After some time, it would all work ok again and you could measure continuity through the motor again. Almost like there was a thermal switch inside the motor that was opening. I see there's a "Breaker Assy" Part Number 31136-90J10 attached to one of the brushes. Does anybody know if that breaker serves this function?

For an update on my progress. Seeing as the motor seemed to be working ok now after clean up, I decided to re-install it and do a very good bleeding / top up of the hydraulic system. After assisting it to go up and down a few times, bleeding the air out of it through the fill port and topping up the fluid each time, it now goes through the full range of motion on it's own. The down stroke sounds perfect however the up stroke wines a bit more and sounds like there's still a bit of air in it. I've cycled it about 20 times (waiting a few hours between cycles) and it's sounds the same. It definitely is working much better than when I started all of this and doesn't hesitate on the last part of the up stroke anymore. I think at this point, I'll run with it for the rest of the summer season and see how it goes. Suzuki isn't able to supply a new electric motor or hydraulic system for months anyway. Has anybody had any luck with aftermarket motors just in case I need one? The OEM part number is 38100-87L00 or 38100-87L03. How about finding seal kits for the hydraulic system? I found a company in Florida that will rebuild the hydraulic system for you (Five Star Marine) so I just want to be prepared.

By the way, my engine is a 2012 and not a 2008 as I initially stated above. I can't figure out how to edit the past though.

[redlowrey]

It is current limiting that is why I wanted you to connect up an amp meter and see how much it goes up when the motor slows down, it would have been interesting to see how much current it took before it opened.

[Ish1978]

It is current limiting that is why I wanted you to connect up an amp meter and see how much it goes up when the motor slows down, it would have been interesting to see how much current it took before it opened.

All I have is a basic multimeter and I don't think I'm able to check current through a "large" motor with it? I think it can only handle 15 or 20 amps for very brief periods of time. Do we know how much current this motor is supposed to consume normally? I've re-assembled everything now and bled the system numerous times and it seems to be behaving normally now. I can obviously pull the PTT relay connector off to check the current if this is something I can do with my meter.