Hay & Forage Forum banner
1 - 11 of 11 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
My 616 suddenly stopped working. Troubleshooting found input shaft turning but discs not turning.
Figured the bevel gear or bottom bearing failed.
Tried to take bevel gear transmission off but can’t get rear pivot arm off the two pins.
Tried soaking, prying, heating. About out of options. Looks like someone had this apart before since there is evidence of heating on the front pivot arm.
I have been working to get it off for 3 days and about to give it up.
Thanks,
Bill
 

·
Senior Member
Joined
·
2,953 Posts
There is enough of a gap between the arms and frame to drive a chisel down between the two parts. You can take either arm off but the pulley will need to come off first if you take the front arm off. You will probably have to take the pulley off anyway if there is damage in that box. Removing the pulley will also give you more room to hit the arm once you drive the chisel in To help break the arm loose. Plus there is not a big gap between the arm and pulley to work the arm.

The pins of the frame are a snug fit in the arms so if you do not try to work the arm evenly the arm will bind and not come off. There is little room for rust to occur. Pins are greased along with the arm at the factory mainly for painting, but I leave grease on the parts when assembling.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #3 ·
There is enough of a gap between the arms and frame to drive a chisel down between the two parts. You can take either arm off but the pulley will need to come off first if you take the front arm off. You will probably have to take the pulley off anyway if there is damage in that box. Removing the pulley will also give you more room to hit the arm once you drive the chisel in To help break the arm loose. Plus there is not a big gap between the arm and pulley to work the arm.

The pins of the frame are a snug fit in the arms so if you do not try to work the arm evenly the arm will bind and not come off. There is little room for rust to occur. Pins are greased along with the arm at the factory mainly for painting, but I leave grease on the parts when assembling.
Thanks so much. I have the pulley off already. I was driving a nail bar in the gap and it looked like the upper pin was moving but the lower not. Perhaps I have created a bind and need to tap on the arm at the top pin to relieve it. It felt so solid that my wife asked me if there was another pin or bolt.
I’ll keep working on it. My only other choice is a slightly used 108 if I can’t fix this by next week. No one around here will even try to work on it.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #4 ·
Sure enough, I took my pry tools out and knocked it back where the largest gap was and put a wedge in where the gap had been smallest and got them out. Made sure I used equal pressure.
Thanks so much for your help. I just didn’t realize how close the tolerance was on those pins.
I am going to pull the end plate tomorrow and see how bad it looks. I managed to locate an overhauled transmission and am wondering if that would be safer than trying to repair myself.
 

·
Senior Member
Joined
·
2,953 Posts
Before you pull the back plate separate the gearbox from the cutterbar and take a look at the gears. Sometimes you can get lucky and only need to replace the module pinion shaft. If the bottom external gear is damaged then disassembly will be required.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #6 ·
Finally got the transmission off. I hope that bottom gear isn’t supposed to be shiny.
I found what was left of a roller bearing and race in the bottom. Haven’t pulled the bottom module yet to see where the bearing came from.
The gears have a cast appearance to them. No obvious broken teeth. All those rollers were down in the oil. No sharp fragments though. Trying to study the parts book but they use the same find number for the bar end of the shaft and the other end. I’m probably just tired and missing something.
 

·
Senior Member
Joined
·
2,953 Posts
Moisture can be a killer to any gearbox. There is a reason mfgs recommend changing the cutter bar oil every year. To compound the problem on these disc mowers is people forget, or were never informed, there is a separate module below the large main gearbox. and fail to even check the oil level in the drive module. It also appears someone put grease into this module.

The pinion shaft where the bearing went out is the same one used for the disc modules. The kit comes complete with everything you need to rebuild the drive module. Simple repair after the module is removed from the cutterbar.

If you go to my pinned thread at the top of the machinery forum, My NH Repair etc, and go down to the discbine section you will find information on repairing the module and cutter bar disassembly. The only difference is torquing the long tie bolts. On the rest of your bar and on the discbines, you torque the nuts to 50 ftlbs and tighten another 5 flats. On the long tie bolts the torque is still 50 ftlbs but tighten an additional 7 flats.

You will also see you do not have an oil slinger under the hubcap of your drive module. Unlike the other modules none is required in that location since oil can pool in the hub cap. Something else I do is replace the internal hex oil level plug and install a regular pipe plug. I use the same plug as the drain plug on the other modules. It is a hex headed plug. When sealing the main gearbox to the cutter bar, I use ultra black silicone. To seal, lay a bead around the shoulder on the bottom of the main gearbox and around the large hole next to the shoulder. No need to add any other silicone to the mating surfaces. Use new bolts and washers when bolting the main gearbox to the drive module. The new bolts are grade eight with a locking patch already applied to the bolts. Torque the bolts to 116 ftlbs. After the main gearbox is bolted to the drive module remove the plug at the front lower flange of the main gearbox, where the oil is added to the drive module, and take a screwdriver and clean out any silicone that is blocking that oil passage. The drive module as well as the other modules take 10oz of 80w90 oil.

Since it appears the gear ran without any lubrication there may be slight wear to the top gear. Keep in mind, the bearing above the gear also ran without oil. If you choose to reuse the gear, which I have done in certain situations, turn the main gearbox upside down and add a small amount of oil to the bearing as you rotate the shaft. It does not take much just enough so there is an oil film on the rollers. Just make sure no oil gets near the surfaces you will seal with silicone. Since the gear will have some wear you will notice an increase of noise coming from those gears until they wear into each other.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #11 ·
I would like to thank you again for your help. I got everything back together and ran it over 12 acres without problems. I stopped at the end and checked the temperature with my hand of all the modules and nothing was very warm. The transmission seemed fairly hot but I could hold my hand on it.
The hex plug in the drive module stripped out and while I realize I probably should have drilled it out and replaced it before finishing, time was pressed. Not sure what I am going to do to get it out later.
Had a bit of a problem sourcing parts but finally got them.
Thank you again, you gave me some long distance confidence.
 
1 - 11 of 11 Posts
Top