NH688 Bearing Failure on Middle Roll - Machinery - HayTalk - Hay & Forage Community

Jump to content




Photo
- - - - -

NH688 Bearing Failure on Middle Roll


  • Please log in to reply
8 replies to this topic

#1 Jerry/MT

Jerry/MT

    Member

  • Members
  • 49 posts
  • LocationWestern Montana

Posted 17 July 2020 - 02:44 PM

We've had a pretty wet spring and early summer so I waited until last weekend to mow our 20 acres of hay. I checked out the baler including running it without load to listen for any bad signs and i checked the bearing housing temperatures with an infra red thermometer. All was well. 

I had the raked and started to bale on Tuesday evening. The windrows were very full because of the late cut and I  ran in a lower gear with higher engine rpms so as not to force too much hay into the pick up. I made 4 beautiful  net wrapped bale and as I was about to wrap the fifth bale I heard a squeal that sounded like the Bale Command II beeper that says kick out the bale.

Now i know it wasn't the beeper  that I heard . It was the failure of the pivot roll bearing because the bale came out unwrapped.  I saw some smoke in the front of the baler and when i climbed up to look, there was a wisp of hay smoldering on the left hand side of middle roll. I had some bottled water in the cab so I pulled the wisp of hay out and poured water on the smoldering hay and the obvious warm left end of the middle roll. I got the thermometer out and recorded 260°F on the right side end of the pivot roll and the left end was warm to the touch

The left end of the middle roll was discolored from the heat but i didn't record the temp. Looking at the gears from the opening between the guard and the middle roll, the gears looked misaligned. I think the bearing failure allowed the gear to come out of alignment but I not sure if it was the right side bearing that failed first and that caused a failure of the left bearing or vice versa. 

 

This baler had 22,000 bales on it five years ago andIi have made some minor repairs ( tailgate cylinder, pickup teeth, bale shape sensor, etc) that I would have expected from a baler with this type of usage. the local dealer ran it before delivery for four hours and checked the bearing temperatures and they were all consider normal (~`100°F) and said if they get above 130°F  that would not be good. I don't think a bearing failure especially with  this usage is abnormal. It's just normal wear and tear.

 

I worked my way through college as and equipment repair mechanic in a steel mill so I'm not afraid of attempting a repair and I reviewed Mike10's excellent repair post but at age 77 I'm not sure that I could physically do it. I put up under 100 bales a year so the question I have, it it worth doing on a old, but otherwise good running baler? Any idea what a dealer would charge to do the repair? You more experienced hay baler have always given me good advice so I'd appreciate some more of that for this situation.

 

Thanks in advance.



#2 8350HiTech

8350HiTech

    Hay Master

  • Members
  • 5234 posts
  • LocationOrrstown, PA

Posted 17 July 2020 - 03:39 PM

It is absolutely worth repairing. Could you get someone to assist you with the repair? As you noted, having the Mike10 instructions makes it easy to follow, so you just need to borrow a little muscle especially for reinstallation of the roll once the bearings are replaced.

#3 mike10

mike10

    Senior Member

  • Members
  • 2298 posts
  • LocationSouthern Indiana

Posted 17 July 2020 - 09:48 PM

The gears on the rolls do not align with idlers.  The idlers are offset about 1/8 to 3/16” from the roll gears.  Take a pry bar and pry up on the rolls at each end.  The rolls should not have any vertical movement.

 

I remove and install the rolls by myself.  I use two sets of cam operated straps on each end to raise and lower the rolls which makes the job fairly easy.  The straps similar to ratchet straps give you fine control when moving the roll into position.  With two straps hooked together on each end I can lower the rolls enough to reach the rolls from the floor.  You can lift One end of the roll and remove the strap from the roll and then rest that end on the axle or floor roll being careful the other end does not slide off the strap on that end.  Remove the other strap and slide the roll off the baler.  It does take some lifting to move the roll into position to install the straps on assembly and you may want to get help to put the roll back on the straps.  From there it is just a matter of raising each side a little bit at a time to get the roll back into place.  Pull up on the tight side of the strap while pulling down on the loose end of the strap that goes through the cam to raise the roll.  Hold the loose end while opening the cam to lower the roll.


  • r82230 likes this

#4 r82230

r82230

    Hay Master

  • Members
  • 3380 posts
  • LocationThumb of Michigan

Posted 18 July 2020 - 09:03 AM

Do repair?  definitely yes

Do it myself? definitely no

Follow Mike instructions? absolutely a positive definitely YES

Do it myself? still a NO

 

Larry



#5 Jerry/MT

Jerry/MT

    Member

  • Members
  • 49 posts
  • LocationWestern Montana

Posted 20 July 2020 - 04:49 PM

Thanks guys. I'm evaluating my options. 



#6 Jerry/MT

Jerry/MT

    Member

  • Members
  • 49 posts
  • LocationWestern Montana

Posted 22 July 2020 - 07:30 PM

Attached File  DSC_0062.JPG   143.15KB   0 downloadsAttached File  DSC_0063.JPG   174.41KB   0 downloadsAttached File  DSC_0065.JPG   119.32KB   0 downloadsAttached File  DSC_0066.JPG   103.66KB   0 downloadsAttached File  DSC_0068.JPG   110.73KB   0 downloads

 

Here's a few pictures of our baler post-bearing failure. (62)

The first shot is the sprocket attached to the pivot roll where I measured 260 °F after I disconnected the pto.

 

The second is the LHS of the middle roll and the pivot roll. Note the heat discoloration at the edge of the pivot roll and the large gap between the pivot roll and the guard. (63)

 

The third is a close up of the pivot roll and the guard. You can see the heat discoloration on the edge of the roll and the gears behind the guard.(65) (66) is a close up of the same.

 

The next two pictures (67 & 68) show the difference in the gap between the middle roll and the pivot roll  from the left and right side.

 

Mike10,  do these pictures help diagnose what the issue might be? 

 

This is the first time I tried to post pictures on this forum. 

Attached Files



#7 mike10

mike10

    Senior Member

  • Members
  • 2298 posts
  • LocationSouthern Indiana

Posted 22 July 2020 - 08:03 PM

The reason you had a high temperature on the right side is because that is a slip clutch for the sledge rolls and was probably slipping.

 

You either have a bearing out on the left side or the small hub which supports the roll broke.  The hub goes through the sledge frame into the support which is mounted to the bearing in the gear.  
 

You can take the tension off the belts and lower the tailgate enough so you can still enter the baler.  LOCK THE TAILGATE.  With a helper push the sledge frame all the way forward.  The roll attaching bolts are now visible through the holes in the side sheets.  If the hub is broken or the bolt broken it should be apparent.  If that is the case, there may be damage to the hole in the sledge frame.  The hole can be repaired, but you may want to take it to the dealer.  I have a post in my pinned thread where I show how I repair the damage.



#8 Jerry/MT

Jerry/MT

    Member

  • Members
  • 49 posts
  • LocationWestern Montana

Posted 23 July 2020 - 04:09 PM

The reason you had a high temperature on the right side is because that is a slip clutch for the sledge rolls and was probably slipping.

 

You either have a bearing out on the left side or the small hub which supports the roll broke.  The hub goes through the sledge frame into the support which is mounted to the bearing in the gear.  
 

You can take the tension off the belts and lower the tailgate enough so you can still enter the baler.  LOCK THE TAILGATE.  With a helper push the sledge frame all the way forward.  The roll attaching bolts are now visible through the holes in the side sheets.  If the hub is broken or the bolt broken it should be apparent.  If that is the case, there may be damage to the hole in the sledge frame.  The hole can be repaired, but you may want to take it to the dealer.  I have a post in my pinned thread where I show how I repair the damage.

 

 

Thanks Mike10.

 

Which roll has the bearing or hub damage, the middle roll? Will I have to do anything on the slip clutch? Is there any other things I should check out while I am at this. I'd hate to do this job and then have to go back in to do something else.

 

Can you list the size of the bolts used in your " sledge frame roll repair tool kit"? Between that and the NH repair manual, I have an idea how to tackle this job but I need a place to work. Using the belts to support the rolls will make it possible for me to do this. Thanks for sharing your experience. We are in the process of selling our ranch and we are moving to Idaho. This will be an ideal winter project to keep me busy!

 

I have a new set of belts and it looks like if I remove the existing belts I won't have to remove the follower roll. Is this a correct assumption?

 

More questions to come.



#9 mike10

mike10

    Senior Member

  • Members
  • 2298 posts
  • LocationSouthern Indiana

Posted 24 July 2020 - 07:07 AM

The middle roll appears to be the one with the problem.  The slip clutch should be alright.  You might take a look at the lower sledge idler gear between the pivot roll and the middle roll for excessive wear.  The top idler gear does not wear as fast and should be ok.

 

I use a 12mm x 7" bolt to help line up the roll so the small hub can be installed.  I use a 16mm x 3 bolt to push the idler gears off the supports.  This only works if the rolls are still in place.  If the rolls are removed, then the supports can be driven out from the inside of the baler.

 

Chances are you will remove the follower roll either because of bearings or to weld the groove worn into the sledge frame.






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

× Sponsors