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444 Posts
Discussion Starter · #1 ·
Our wheat harvest went very smooth till the last field. With only
30 acres left, the cleaning fan smashed itself into a crumpled mess.

Somehow the paddles hooked the rear opening of the fan housing
pulling it down enough to mangle all the paddle blades and the
spokes that hold the blades .

Not sure yet what happened till I get the whole fan housing
and fan dropped out tomorrow but from what I can see through
the sides it looks like one of the spokes broke and allowed
the paddle to bend out enough to contact the fan shroud in the
center area of the paddle fan. The reason I think this is that
all the spokes are bent except this one spoke that is broke off.

May be I can learn something while I am fixing it and will post it
for someone else's benefit.

Looks like it will need all new spokes , paddles, top rear of the fan housing and all new louvers on the top of the fan housing.

Good wheat though the last field went close to 90 bu /acre.

Got the neighbours to do the last little bit of wheat because its
gonna be a while till I get this mess fixed.

· Registered
444 Posts
Discussion Starter · #3 ·

Got the fan housing off in about 3 hours this morning.
Half that time was trying to figure out how to get it off.
Had to take of alot of shields to get room to work.

I used a motorcycle hoist on one side and a come along
on the other to hold it while I took out the 4 main holding
bolts out then lowered it to the cement.

The cause of this little disaster was a broken spoke
in the middle of the fan. I speeded the fan up a little
while before this happened. The rotating force bent
that paddle out and it hooked the rear lip of the
housing pulling it down for the other paddles to
hit also. Also the vibration broke one of the air
deflectors loose and threw it onto the clean grain
auger but did not jam anything up. The louvers
on top the fan housing will all need replaced but
the rest of the housing is ok. Heavier weld in louvers
are available through NH parts.

Ill get some pictures of the bent stuff tomorrow
when I finish taking the fan apart.

· Registered
444 Posts
Discussion Starter · #5 ·
I have seen the positourque or something like that name in the
parts book. I thought it may be something like the spring in a
can like the old masseys had but never really knew what that
was about. Harvesting wheat I can get the cylinder to slow down
a bit if the conditions are good but usually I have to reduce speed
due to the sieve losses before that happens. The sieve cleaning
seems to be the limiting factor for this machine.

The two speed gearbox has a couple of advantages though. You can
click the shifter to the middle position and the cylinder freewheels
which is handy sometimes when you are working on it.
Also if I plug it I can clear the back of the machine out first
before trying to get the slug loose. It also seems that if you
plug it the belt goes loose and it will tighten back up if you run
it in the neutral position for a short time before powering the slug
through. Does not plug often but when it does rarely do I get the
big wrench out.

We need the 2 speed gearbox on there to do corn.

· Registered
444 Posts
Discussion Starter · #7 ·
I also had a **** go through a couple years ago.
Maybe this is what caused the one spoke to break.
Its hard to see in there with all the dirt-leaf shields
in place. The spoke could have been broke for a while.
My **** bent all the paddles on the grain leg.
What a mess cleaning him out of there.

· Registered
3,259 Posts
I'm looking forward to the pics of the fan housing. I've heard all good stuff about the NH fans and would like to maybe copy the louver design over to my IH.

Since you posted this mishap, I've been keeping a closer eye on my fan as it is getting older and maybe I should consider new spokes just to reduce my chances of this happening to me.


· Registered
444 Posts
Discussion Starter · #9 ·

These are the louvers that need replaced. They act as an air intake
just under the grain pan. Ill need to grind down all the spot welds
to remove them. The new ones are 1.5mm compared to these older
1mm thick metal thickness.

This is the broken spoke that probably caused all the damage.

Sanded all the paint off the shaft and used this air riveter
with a blunt tool to move all the spoke hubs off the end
of the fanshaft. Ill paint the shaft again so the next guy
to work on it (hopefully not me) will not be sanding rust off.

Bent stuff and Jack Russel mouse inspection.

This is the left fanshaft bearing and it was still good.

The right fanshaft bearing ran a little rough. It would have
been difficult to find this out without disassembly like this.

Monday Ill get all the part numbers looked up and get
them ordered.

· Registered
3,259 Posts
WOW !!!! Thanks for the pics and update. I like the pillow blocks better than the flange type IH uses. May have to call the NH wrecking yard for a complete fan to install in the IH. I see the housing is different shaped to make the louvers work.

Looks like your JR is getting into the picture too.
Whats its name?

· Registered
34 Posts
I had a tr 86 and the previous owner had brazed the end of one paddle up to keep going and one night just like you (one 3 ft strip) the paddle let go and it wrecked the air deflector (towards the shoe) and all the fan blades and spokes...We took it apart (but left the assembly attached to the combine) and fixed it all in place...I am glad my arms were long enough to reach the middle. It also had a high spot on the shroud that we tapped back out so it wouldn't hit. The last thing we noticed was that the fan shaft wasn't square to the air deflector. It would touch on one side and was 1/2 inch out on the other....So we backed off the side closest and left it there.

Just what I remember of it....You and I have talked on the phone about your combine a couple of times. I hope it is still treating you good.


· Registered
444 Posts
Discussion Starter · #13 ·
I picked up the parts but have not got started the rebuild yet.
While the fan is out it is easier to see some of the shaker
mechanism and I noticed one of the rubber bushings was
gone on the connecting rod between the top sieve and
the pitman. There also was some trouble with the
part that connects the top sieve to the bottom. It is sort
of a teeter totter like assembly that causes the top sieve
to move in the opposite direction as the bottom.
The pivot axle of this teeter totter was broke on the left
side of the machine so it was relying on the duplicate
assembly on the right side of the shoe to do all the work.
Glad to see this before it caused any problems. It should
not be very difficult to make this part right again with the
fan out of the way.

· Registered
444 Posts
Discussion Starter · #15 ·
This is the "teeter totter" pivot that I found broke after removing
the fan housing. The new part and replacement bushing is above it. This plate is bolted to the combine frame and the other part bolts to the "teeter totter" where it pivots to make the sieves move in oposite dirrections. The bushing is rubber surrounded i guess to be a shock absorber for vibration and sound to the rest of the machine. I call it the "teeter totter" because NHs name for does not say anything about what it is. Technically it is something like a bellcrank.

I could not get my camera jammed up into the place where the
other rubber piece was wore out on the end of the connecting rod
that runs from the pitman to shake the sieves so no pics. It was just a rubber piece surrounding a stub shaft and was held on with
2 cast pieces with 2 bolts through them.

Mig Welding
Started on the6 louvers today. I used every vice grip and c clamp
I could find and got them all in and rebent till they fit well.
Borrowed a MIG welder and figured out how to use it. It does a
much better job than Dads old buzz box on this thin metal. Kind
of tricky to get all the dials set right. It really worked much
better after I cleaned the paint off. Learned alot today.

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18 Posts
Did the same to my CR9070. Bearing support on left side (non-driven end) broke, fan fell down at 1000 rpm's. Must be a vibration somewhere to have caused it to break. Took out blades, and deflectors behind fan and bottom of shroud.

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444 Posts
Discussion Starter · #17 ·
I would like to balance this before I put the fan into the housing but the fan will not go into
the housing in one piece. It needs to be assembled piece by piece inside the fan housing.
Before I put the drive belt on i can see if it stops in the same place when spinning it by hand.
The seals on the new bearings may make this idea not work so well.

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3,259 Posts
Are you absolutely sure it needs to be installed piece by piece? I dont have a NH book, but my fan on the 1680 IH can be removed in one piece. You pull the center shaft out of the hubs and then the housing unbolts on the bottom and the fan will come out under the combine. Have to jack the rearend up, but it can be taken out in one piece. I'd sure think NH would've made a similar provision. ?

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444 Posts
Discussion Starter · #19 ·
It looked like it would not come out in one piece through the bottom removable panel. I took the fan apart through the opening in the back which was easier because the housing was off and sitting on the removable panel. I could not see how the fan shaft could be dropped through the bottom door without being able to slide it one way first which was not possible due to the paddles and spokes. Removing the bottom panel did not open up the bottom of the air intake holes in the sides of the fan housing.
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