Massey Fergusson 165 Diesel Starter Issue

[Lee_K]

I will start from the beginning on this one. This summer the starter/solenoid started just clicking when you turned the key, but after a few attempts it would turn over and start. A couple weeks ago it got to the point that the engine would not turn over, the solenoid would only click. I used a multimeter and diagnosed it as the solenoid as there was no voltage getting to the starter. I could actually use a big wrench and get the engine to turn over by jumping the terminals. I attempted to clean up the old solenoid contacts and was able to rotate the one that was badly worn so the plunger would hit an unworn spot. When I put the solenoid back on I still just got a click, but no return click. I figured out the solenoid had stayed engaged and when I disconnected the battery I got the return click I expected to hear when I let off the key. After getting a new solenoid and installing it, when I hit the key the tractor turned over great, but when I let off the key it continued to spin the motor until I disconnected the battery. I tried this a couple times with the same result. Note, I left the stop pulled out so the engine would not start on all attempts. I talked to my mechanic and he mentioned the drive can get sticky and hang up internally. He also mentioned to make sure none of the wires/connections were accidentally twisted and touching when I put it back together. I took the starter off and cleaned the drive as best I could bench tested it and it worked great. I reinstalled the starter being careful not to turn the posts on the solenoid or accidentally short a connection. It still continues to crank after letting off the key. I took the starter off again completely disassembled it and cleaned all the moving parts and lightly lubed them with dry lube. After reassembly I bench tested the starter again, and it worked fine. It engaged and disengaged like it was supposed to. When I put the starter back on the tractor it still wants to keep spinning the motor until I disconnect the battery. I also tried disconnecting the key switch and using a wire energize the start terminal in case there was a problem with the key switch.

In summary here the starter / solenoid works like it should in the vice/on the bench, but will not disengage on the tractor. I even tried using jumper cables to energize the starter/solenoid on the the tractor like I used on the bench, but it still wants to keep cranking. My mechanic is recommending a new starter. My question is, Is there anything else I can try before buying a new starter? This whole situation has me stumped.

Sorry for the long post.
Thanks,
Lee

 

[Brown David]

I will start from the beginning on this one. This summer the starter/solenoid started just clicking when you turned the key, but after a few attempts it would turn over and start. A couple weeks ago it got to the point that the engine would not turn over, the solenoid would only click. I used a multimeter and diagnosed it as the solenoid as there was no voltage getting to the starter. I could actually use a big wrench and get the engine to turn over by jumping the terminals. I attempted to clean up the old solenoid contacts and was able to rotate the one that was badly worn so the plunger would hit an unworn spot. When I put the solenoid back on I still just got a click, but no return click. I figured out the solenoid had stayed engaged and when I disconnected the battery I got the return click I expected to hear when I let off the key. After getting a new solenoid and installing it, when I hit the key the tractor turned over great, but when I let off the key it continued to spin the motor until I disconnected the battery. I tried this a couple times with the same result. Note, I left the stop pulled out so the engine would not start on all attempts. I talked to my mechanic and he mentioned the drive can get sticky and hang up internally. He also mentioned to make sure none of the wires/connections were accidentally twisted and touching when I put it back together. I took the starter off and cleaned the drive as best I could bench tested it and it worked great. I reinstalled the starter being careful not to turn the posts on the solenoid or accidentally short a connection. It still continues to crank after letting off the key. I took the starter off again completely disassembled it and cleaned all the moving parts and lightly lubed them with dry lube. After reassembly I bench tested the starter again, and it worked fine. It engaged and disengaged like it was supposed to. When I put the starter back on the tractor it still wants to keep spinning the motor until I disconnect the battery. I also tried disconnecting the key switch and using a wire energize the start terminal in case there was a problem with the key switch.

In summary here the starter / solenoid works like it should in the vice/on the bench, but will not disengage on the tractor. I even tried using jumper cables to energize the starter/solenoid on the the tractor like I used on the bench, but it still wants to keep cranking. My mechanic is recommending a new starter. My question is, Is there anything else I can try before buying a new starter? This whole situation has me stumped.

Sorry for the long post.
Thanks,
Lee

I don't think I can help with your problem but I'd like to say there's no need to apologize for the long post at all.

You very clearly explained what you have and what was/is happening. That should help get results.

Good luck getting going again.

 

[DanielW]

A few folks have had similar problems on different tractors. In those cases it turned out that when they'd hit the starter, the solenoid plunger would not only jumper between the main contacts, but also send power to the solenoid excitation wire, which kept it engaged/spinning. If you turned the post inside the solenoid to get a fresh contact spot, that might be your issue. Ultimately, anything that causes the excitation wire to be jumpered to the down-stream (not battery) terminal would cause that issue - once you send voltage to it the first time it would keep itself energized. If you were bench testing with just a pair of booster cables by touching to the terminal you wouldn't have noticed it (assuming you just touched it by hand and pulled away once you saw it working)

The first steps I'd do: With all the wires disconnected from the starter, check for continuity between the (small) solenoid excitation terminal on the starter and the battery terminal on the solenoid. There shouldn't be any continuity. If that all checks out, hook the two primary terminals up to the starter but leave the excitation wire disconnected. Check for voltage between the excitation wire and ground with the key/button in the 'start' position. You should get full voltage. Then release the key/button it so it's back to the 'on/run' position and you should have no voltage at the excitation wire. If that all checks out, it must be a sticky starter solenoid that just happens to be sticking when it's on the tractor and not on the bench, or (more likely) the solenoid plunger is somehow making contact with the excitation wire terminal when it's engaged.

 

[Dieseltech]

I've had this happen before on a Delco MF 265 starter. What happened on it was the heavy thrust washer that snaps over the armature snap ring had broken off, allowing the solenoid to stay on when it should release when the drive linkage over traveled. That washer limits the drive from traveling too far, which will cause starter trouble. If I recall there are three parts, a snap ring, heavy washer and thinner wear washer the drive makes contact with.

 

[Lee_K]

I believe the new solenoid is good. When bench testing I would use a small wire to excite the the start terminal on the solenoid. There is in fact continuity between the start terminal and the starter lug, but none between the batt lug and the start terminal. The continuity between the start terminal and starter lug is normal and is due to a pull in winding. The start terminal gets full voltage but actually still has around 6 volts when the key is released. This did not seem right to me at first, but after some research I think its normal due to the configuration of the two different windings in the solenoid. I will also note that the starter only spins until the battery is disconnected then once the battery is reconnected it will not turn until the key is turned. Also note here that the key only controls the starter.

Dieseltech, Im not sure I follow, but I had everything on the armature apart except the over run clutch and I did not find any broken parts.

Thanks,
Lee

 

[Dieseltech]

I believe the new solenoid is good. When bench testing I would use a small wire to excite the the start terminal on the solenoid. There is in fact continuity between the start terminal and the starter lug, but none between the batt lug and the start terminal. The continuity between the start terminal and starter lug is normal and is due to a pull in winding. The start terminal gets full voltage but actually still has around 6 volts when the key is released. This did not seem right to me at first, but after some research I think its normal due to the configuration of the two different windings in the solenoid. I will also note that the starter only spins until the battery is disconnected then once the battery is reconnected it will not turn until the key is turned. Also note here that the key only controls the starter.

Dieseltech, Im not sure I follow, but I had everything on the armature apart except the over run clutch and I did not find any broken parts.

Thanks,
Lee

I'd pull the starter again and see if those washers are in place, just inside the nose end bushing. If not, then the drive gear will travel TOO FAR as those washers limit the drive travel. Only seen this happen once as an OLD MF mechanic, but can happen on any Delco starter no matter what engine brand.

 

[Lee_K]

It works!
I must admit I was skeptical. Through my searching I found a diagram on this site that shows only the nose of the starter, and it shows no washer (that I can tell). However when I disassembled the starter the first time I noticed there were two washers on the brush end of the starter and thought it was odd. So with nothing to loose I moved one of those washers between the nose and the drive gear and it works. The starter engages and disengages normally. I will include that diagram for reference.

THANK YOU for all the help especially Dieseltech.

Thanks again,
Lee

 

[Dieseltech]

It works!
I must admit I was skeptical. Through my searching I found a diagram on this site that shows only the nose of the starter, and it shows no washer (that I can tell). However when I disassembled the starter the first time I noticed there were two washers on the brush end of the starter and thought it was odd. So with nothing to loose I moved one of those washers between the nose and the drive gear and it works. The starter engages and disengages normally. I will include that diagram for reference.

THANK YOU for all the help especially Dieseltech.

Thanks again,
Lee


View attachment 1868

The number 40 spacer washer that fits tight over the snap ring 41 is what breaks sometimes on Delco starters. I always look for that whenever a starter won't stop as it should. Glad you got it working OK again!

 

[miangus]

I will start from the beginning on this one. This summer the starter/solenoid started just clicking when you turned the key, but after a few attempts it would turn over and start. A couple weeks ago it got to the point that the engine would not turn over, the solenoid would only click. I used a multimeter and diagnosed it as the solenoid as there was no voltage getting to the starter. I could actually use a big wrench and get the engine to turn over by jumping the terminals. I attempted to clean up the old solenoid contacts and was able to rotate the one that was badly worn so the plunger would hit an unworn spot. When I put the solenoid back on I still just got a click, but no return click. I figured out the solenoid had stayed engaged and when I disconnected the battery I got the return click I expected to hear when I let off the key. After getting a new solenoid and installing it, when I hit the key the tractor turned over great, but when I let off the key it continued to spin the motor until I disconnected the battery. I tried this a couple times with the same result. Note, I left the stop pulled out so the engine would not start on all attempts. I talked to my mechanic and he mentioned the drive can get sticky and hang up internally. He also mentioned to make sure none of the wires/connections were accidentally twisted and touching when I put it back together. I took the starter off and cleaned the drive as best I could bench tested it and it worked great. I reinstalled the starter being careful not to turn the posts on the solenoid or accidentally short a connection. It still continues to crank after letting off the key. I took the starter off again completely disassembled it and cleaned all the moving parts and lightly lubed them with dry lube. After reassembly I bench tested the starter again, and it worked fine. It engaged and disengaged like it was supposed to. When I put the starter back on the tractor it still wants to keep spinning the motor until I disconnect the battery. I also tried disconnecting the key switch and using a wire energize the start terminal in case there was a problem with the key switch.

In summary here the starter / solenoid works like it should in the vice/on the bench, but will not disengage on the tractor. I even tried using jumper cables to energize the starter/solenoid on the the tractor like I used on the bench, but it still wants to keep cranking. My mechanic is recommending a new starter. My question is, Is there anything else I can try before buying a new starter? This whole situation has me stumped.

Sorry for the long post.
Thanks,
Lee

As I am the master at making simple mistakes myself, I am going to make a suggestion that I do not intend to malign your ability as a mechanic. The return spring didn't get lost or mis-installed when you cleaned the contacts. The only part not renewed when replacing the solenoid is the stud that is attached to the starter case. Maybe that stud is somehow not releasing contact with the moving contact. The drive or drive collar including the pins on the fork could also be damaged preventing retraction in actual use. On the bench a drive will retract due to the inertia and the spiral on the shaft.