• We are no longer supporting TapaTalk as a mobile app for our sites. The TapaTalk App has many issues with speed on our server as well as security holes that leave us vulnerable to attacks and spammers.

Reverse Testing

marpolsdofer

TY 4 Stroke Guru
Joined
Nov 3, 2009
Messages
995
Location
swaledale, IA
If you want to test the gears take off the servo. There is a peace of metal called the fork that you can touch with you finger. Push it to the chain case side, hold it, turn the shaft until it locks in to place, then let go it will stay in place. Transfer to reverse push it to the clutch side and rotate the shaft half turn should go it to place. Forward both shaft will rotate same direction reverse the the shaft will rotate opposing each other. Make sure the smaller chain case shaft is pushed in to the the gear case.

Test the servo- Have the servo off the gear case. Get a 12v battery and two wires. Connect one wire to positive the to negative. On the servo there is 3 pins (1 pin is on the left side from the top looking at the pins it will be alone and 2/3 will be next to each other). Read carefully as it just does not swap for F/R
For Forward connect Neg(-) to 1 and Pos(+) to 2. For Reverse Connect Pos(+) to 1 and Neg(-) to 3.
If actuator moves to the right is in F and if it goes to the right its in R.
The actuator is spring loaded. This will keep constant pressure on the fork until it is shifted in to place and keep it in place once it has. The servo is not supplied constant power to do so.

Testing the sensors-There is on the F side and one on the R side (they are interchangeable with each other). They work just by simple contact from the fork. To test it you cant get a self powered test light and past current from the fork to the sensor (the side it is on) or you cant take of the sensor and test from the ends.

Dry Run-Place the servo in F position. Push the fork in to F position. Place servo back on case. Test it by supplying power to change fork locations for F/R shifts. A fast twist may need to be applied due to tension from the spring. Make sure there there gear are lubed, friction will not help a shift. If it does not fully shift in to place, make sure small shaft is pushed in. If it still does not, the servo gear may be re-indexing if taken apart.

If this all work try a full hook up with everything back together. If this does not work you problem lies with in the Control Pod or ECU. They control when the servo is supplied power to shift (to prevent damages a high RPM shift), D and R lights, and back up alarm.
When putting everything back to getter 1 wire for the sensor will have F on it for Forward, so you know witch sensor is witch.
To make a direct override for addition of reverse - Diagram coming soon for battery connection, switches, and connection to servo.

Pic 1- Yellow Arrow, push the shaft in to direction arrow points. The other Yellow Arrow, what part of the gears the shaft controls. Red Arrows, the shaft and gears it controls. Blue box, inside the box indicates how the gears are aligned and touch. Black indicates the fork.

Pic 2- In Forward gear position.

Pic 3- In Reverse gear position.

Pic 4- Yellow Arrows, indicate witch direction the shaft will rotate in Forward. Red Arrows indicate witch direction the shaft will rotate in Reverse.

pic 5- Testing sensor in Forward with out removing sensor.

Pic 6- Testing sensor with sensor removed.

Pic 7- Servo wire application to change actuator position.

Pic 8- Corresponding Actuator position. Left is Reverse and Right is Forward.

Pic 9- Heavy spring shown in Servo.

Pic 10- Gear re-indexing. Place for in Forward position and place Actuator in Forward position. Top arrow pointing right is the a stop and the bottom is stop. They will contact each other to stop from going to far (unknown how long power is supplied but easier to make that then make senors and some a device for it) When re-indexing make sure they just touch each other and place cover back on.

Pic 11- Just a under view of the cover. # Color Corresponds with the Arrow color for current testing with self power test light. (With #1 sometimes I would get a light sometimes the motor would turn). White Arrow (the stop) is to make sure the gear to go to far and slip out of place.
You will notice the are not all the same length. This is to automatically kill the power once it is full shifted in place. If it was to be bumped out of place it would re-engaged. If the gears are fully in place but the Actuator Arm is not, the power will still be cut. The Arm is spring loaded to keep constant presser until it is engaged and should still do so once its in place.

Pic 12- Yellow Arrow, 3 wires that are used to control the Servo. Red Arrow, wire to Forward Sensor. Blue Arrow, wire to Reverse Senor.

Pic 13- Example of testing.

Pics 14- Contact points (also could be called a brush) for D/R to the complete the circuit.
 

Attachments

  • 12.jpg
    12.jpg
    146.7 KB · Views: 1,111
  • 10.jpg
    10.jpg
    138.3 KB · Views: 1,062
  • 9.jpg
    9.jpg
    161.4 KB · Views: 1,060
  • 8.jpg
    8.jpg
    120.2 KB · Views: 1,011
  • 7.jpg
    7.jpg
    110 KB · Views: 1,068
  • 6.jpg
    6.jpg
    149.4 KB · Views: 1,043
  • 5.jpg
    5.jpg
    140 KB · Views: 1,049
  • 4.jpg
    4.jpg
    119.5 KB · Views: 1,032
  • 3.jpg
    3.jpg
    129 KB · Views: 1,027
  • 2.jpg
    2.jpg
    121.4 KB · Views: 1,033
  • 1.jpg
    1.jpg
    162.8 KB · Views: 1,142
  • 11.jpg
    11.jpg
    190 KB · Views: 1,036
  • 13.jpg
    13.jpg
    145 KB · Views: 1,083
  • 14.jpg
    14.jpg
    141.8 KB · Views: 1,023

Hey Marshall, great write up! I was wondering how to test the servo motor and now I know. Just one question: have you ever had a gear box itself fail mechanically? I may be having an issue with mine where the dog gears for the forward gear are worn on an angle from each other and when engine torque is applied, they push away from each other against the spring in the servo.

I just bought a new servo and putting it in tonight and hope that this was causing my problem but looking with the boroscope, I could see the damage on the edges of the dog gears where they were slipping from each other.
 
If someone could add this to the FAQ that would be great.

This is a great write up!
 
If you are taking about inside the gear case (the metal ones). I looked at both mine (spare and current one) and they both look squared with maybe a slight taper on a few point. There are 3 points for R/F to engage. Since there is some play in both they might be directly across from each other or off set. When you put it in to gear by hand it will not be fully locked in place (it will be engaged but not fully). Only way it will be fully locked is if you hold it there. There is a spring in there some place but the Actuator should hold it in place when the Servo is on.
You could put a magnet in the side and see if you get any metal shaving to find out.

If you are talking about the plastic gears in the Servo, I could see it happening. When you take off the cover if the gears get bumped you will see they will tilt. If the holders in the top cover get damaged they would tilt under a load. If it was tilted and it was powered continuously the cogs could get striped relatively easy.

I think you also asked a question to if there is oil in the case and how much. I am not sure. I think the oil comes from the chain case and passes between the bearings. I will take a look at my spare chain case and find to weather oil passes or you nee to oil level for the Reverse case.
 
Yeah, I was talking about the metal gears. Put the new servo motor in tonight and it's working fine now. There were a lot of metal shavings/flecks in the oil from the gears not engaging properly. I tried to flush out the reverse gear box by pouring oil right into the servo motor hole and it came out by the bearing and a small hole just above the adjuster. I JBWelded a small rare earth magnet onto the dip stick so it should pick up any leftover metal.

It didn't skip even with me on it at full throttle, and I'm no lightweight! I'm just glad the gear box itself is fine.
 
I spoke too soon. It's still slipping/grinding. I've got a line on another used box at a reasonable price so will have to swap it out. Can anybody give some pointers on getting it out?
 
You need to take off the front end, then need to take out the engine. Take off the secondary clutch and take off the gear in the chain case. Take off the full chain case Undo the set screws on the barring an the long jack-shaft (its the side plate with the clutch and it on the inside were the engine sits). Take a block of wood and go to the clutch side of the shaft, place it on the end, take a dead blow and smack it a few times. Let me confirm that it can be pulled from the right side engine plate.
 
Wow! The worst that the manual says is to remove the fuel tank, disconnect the exhaust and pull it back to allow the shaft to clear it. Apparently it can be tilted up and out by the chaincase side with the exhaust out of the way.
 
Forgot about that way. You still need to smack that a few times to get that barring off just dont forget about the set screws.
 
Well I got temporary wiring set up and did a test run for a switch with out the use of Control Pod and new or repined wire harness . So IT CAN BE DONE!!! I will take write a separate one for it. I will take the pics tomorrow, draw something up, write it up, and post it up tomorrow.
 
Hi Marshall. I have the servo off, looks like the fork is in forward. I moved it in and out of forward like you said. It is in forward. Just trying to test servo. Did what you said with the battery and nothing moves either way. Does this mean that the servo is dead? Or am missing something. Going to try and test sensors. Any help would be appreciated. Thanks for all your help. Muncher
 


Back
Top