NH918H Flail: Tightening Belts?
- Thread starter tom_k
- Start date
There is no tension roller/idler. There is no tightening bolt.
Maybe the belts are meant to be replaced as they loosen?
The 3 belts run on 2 pulleys (a large one attached to the drive shaft, a smaller one attached to the cutter shaft).
It looks like they are held on by locking, keyed hubs with recessed hex-head bolts. I'm thinking I need to remove the smaller hub and replace the belts.
I suppose I'll need to use a bar clamp with the heads reversed to push apart the pulleys into tensioned position, then reinstall the hub.
Right?
I can't find a downloadable service manual anywhere.
Maybe the belts are meant to be replaced as they loosen?
The 3 belts run on 2 pulleys (a large one attached to the drive shaft, a smaller one attached to the cutter shaft).
It looks like they are held on by locking, keyed hubs with recessed hex-head bolts. I'm thinking I need to remove the smaller hub and replace the belts.
I suppose I'll need to use a bar clamp with the heads reversed to push apart the pulleys into tensioned position, then reinstall the hub.
Right?
I can't find a downloadable service manual anywhere.
leonz
Super Member
Please type NH918 manual in the search box to see if we have one here on the forum first BEFORE you do anything!!!
OR call Ford NEW Holland Dealer for help!!!!
Most likely you will have to pay for a downloaded manual from Yesterdays Tractors to obtain one or order it from a New Holland Dealer or contact the folks at Flail Master to inquire about a manual.
One of the members here has posted a manual for this mower in the forum and you should type Ford 918 mower in the search box to look for it.
Before you start DOING ANYTHING AND I MEAN ANYTHING!!!!!!
You need to wash away the rubber and grass dust away from both sides
of the flail mower to provide a better view of the parts and bearings.
You have a flail mower with three drive belts.
I believe you have a flail mower that requires you to move the
flail mower rotor and bearings to increase the belt tension.
This requires a bit of work to do AND IT HAS TO BE DONE RIGHT
OR YOU WILL BE IN A WORLD OF HURT and you will lose the flail
rotor bearings!!!!!!!!
Check to make sure there is a slot that both ends of the
flail mower rotor travels to increase or decrease the belts tension.
The cutter shaft is the FLAIL MOWER ROTOR.
Please wait for one of the other members to comment
as we have a large number of members that own this mower.
OR call Ford NEW Holland Dealer for help!!!!
Most likely you will have to pay for a downloaded manual from Yesterdays Tractors to obtain one or order it from a New Holland Dealer or contact the folks at Flail Master to inquire about a manual.
One of the members here has posted a manual for this mower in the forum and you should type Ford 918 mower in the search box to look for it.
Before you start DOING ANYTHING AND I MEAN ANYTHING!!!!!!
You need to wash away the rubber and grass dust away from both sides
of the flail mower to provide a better view of the parts and bearings.
You have a flail mower with three drive belts.
I believe you have a flail mower that requires you to move the
flail mower rotor and bearings to increase the belt tension.
This requires a bit of work to do AND IT HAS TO BE DONE RIGHT
OR YOU WILL BE IN A WORLD OF HURT and you will lose the flail
rotor bearings!!!!!!!!
Check to make sure there is a slot that both ends of the
flail mower rotor travels to increase or decrease the belts tension.
The cutter shaft is the FLAIL MOWER ROTOR.
Please wait for one of the other members to comment
as we have a large number of members that own this mower.
greg_g
Super Member
- Joined
- Dec 18, 2003
- Messages
- 6,086
- Location
- Western Kentucky
- Tractor
- JD3720 Cab, 300X loader with 4-in-1 bucket
The 918H parts manuals are available online at no cost. Simply visit the parts section of any New Holland dealer
//greg//
//greg//
[
I talked to the senior mechanic at my local NH dealer. He had no experience adjusting the belts on the 918H. After I described the belt/pulley assembly, and we had looked at online parts diagrams, he did suggest it might be a type that requires movement of the entire shaft to tighten/loosen the belts.
The NH dealer (and Messick's, and Flailmaster) said they could not identify any service manual for this model.
I replaced the 80 knives myself, but I'm afraid the belt adjustment might be above my skill level if it involves supporting and aligning the rotor shaft while under tension.
I talked to the senior mechanic at my local NH dealer. He had no experience adjusting the belts on the 918H. After I described the belt/pulley assembly, and we had looked at online parts diagrams, he did suggest it might be a type that requires movement of the entire shaft to tighten/loosen the belts.
The NH dealer (and Messick's, and Flailmaster) said they could not identify any service manual for this model.
I replaced the 80 knives myself, but I'm afraid the belt adjustment might be above my skill level if it involves supporting and aligning the rotor shaft while under tension.
leonz
Super Member
Hello TomK,
UGH!
The PDF I have uploaded for you is from the Messick home page...............
Your 918H has a non adjustable belt system which
is also very good and goof proof.
Please be sure to use the kevlar green belts for the replacement belts as they resist the shock loads much better than the standard belts.
ANOTHER BIG ITEM
When you go to purchase the three replacement belts be sure that the three belts have the same lot number otherwise you will have problems with a belt or belts not gripping and failing prematurely.
View attachment 322363
If you feel confident enough to do it, you can walk the new belts across the pulleys one at a time or remove the upper pulley and replace the three belts and slide the pulley across the drive shaft stub while hold the belts on the lower pulley.
UGH!
The PDF I have uploaded for you is from the Messick home page...............
Your 918H has a non adjustable belt system which
is also very good and goof proof.
Please be sure to use the kevlar green belts for the replacement belts as they resist the shock loads much better than the standard belts.
ANOTHER BIG ITEM
When you go to purchase the three replacement belts be sure that the three belts have the same lot number otherwise you will have problems with a belt or belts not gripping and failing prematurely.
View attachment 322363
If you feel confident enough to do it, you can walk the new belts across the pulleys one at a time or remove the upper pulley and replace the three belts and slide the pulley across the drive shaft stub while hold the belts on the lower pulley.
Thanks!
However, it appears there actually is an adjustment bolt, but it's not inside the belt-and-pulley housing where I'd been looking.
Messick diagram #002 (FRAME AND RELATED PARTS) shows a horizontal bolt (#2 in the diagram, part ME0000094. The head of this bolt rests against the drive shaft housing.
Diagram #006 (GEARBOX) shows a vertical screw (#33 in that diagram).
It looks like I can loosen that vertical screw to free the drive shaft housing, labeled "EXTENSION" (#32 in the latter diagram), to travel toward the front or rear of the deck.
Then the horizontal bolt can be loosened or tightened to make the Extension move toward the front or rear of the deck.
This will move the upper pulley toward the lower pulley (to loosen the belts) or away from the lower pulley (to tighten the belts).
That's what it looks like to me, anyway.
Can anyone confirm that this is the procedure?
However, it appears there actually is an adjustment bolt, but it's not inside the belt-and-pulley housing where I'd been looking.
Messick diagram #002 (FRAME AND RELATED PARTS) shows a horizontal bolt (#2 in the diagram, part ME0000094. The head of this bolt rests against the drive shaft housing.
Diagram #006 (GEARBOX) shows a vertical screw (#33 in that diagram).
It looks like I can loosen that vertical screw to free the drive shaft housing, labeled "EXTENSION" (#32 in the latter diagram), to travel toward the front or rear of the deck.
Then the horizontal bolt can be loosened or tightened to make the Extension move toward the front or rear of the deck.
This will move the upper pulley toward the lower pulley (to loosen the belts) or away from the lower pulley (to tighten the belts).
That's what it looks like to me, anyway.
Can anyone confirm that this is the procedure?
leonz
Super Member
The adjustment you see is for the cross shaft as the same parts can be used for all the flailmowers by sliding the tube out from what I remember of it.
If you look at drawing 004 you will see that there is no adjustment on either side of the flail mower shroud/hood/housing, If there was there would be a drawing of the left side of the shroud/hood/housing and there would be an accompanying VERTICAL tensioner next to the V belts ON BOTH SIDES
requiring you to count the number of threads on the adjustment jack bolt before you use the lock nut to secure them in place.
The bearing mounts on both sides would be required to have adjustment bolts to slacken the tension on the rotor.
They have simplified this and taken it out of the work to eliminate bearing missalignment when changing belts by simply walking the belts across the three grooved pulley.
When you buy the new belts be sure to leave them in the sun for a bit to warm them up before you install them. Do not use belt dressing in any case as itis highly flammable!!
I found the Operators Manual on the NH site. NH charges $7.13 for a pdf download and another $12.21 for a parts catalog.
Page 9 of the OM describes the belt adjustment procedure.
It's pretty much as I described above, but there are also 4 vertical fixing bolts under the gearbox, and another horizontal adjusting bolt above them. After loosening the fixing bolts, you screw the two horizontal bolts an equal number of turns to move the upper pulley toward/away from the lower pulley.
I did manage to walk the old belts off without any adjustment. After leaving the new ones in the sun, I managed to walk the innermost belt on and into correct position. I may have to work the adjusting screws first before I can get the others on completely, then tighten it up.
Thanks for the advice! Leaving the belts in the sun was a good, simple tip.
Page 9 of the OM describes the belt adjustment procedure.
It's pretty much as I described above, but there are also 4 vertical fixing bolts under the gearbox, and another horizontal adjusting bolt above them. After loosening the fixing bolts, you screw the two horizontal bolts an equal number of turns to move the upper pulley toward/away from the lower pulley.
I did manage to walk the old belts off without any adjustment. After leaving the new ones in the sun, I managed to walk the innermost belt on and into correct position. I may have to work the adjusting screws first before I can get the others on completely, then tighten it up.
Thanks for the advice! Leaving the belts in the sun was a good, simple tip.
sfabern
New member
Re: NH918L Replacing Rotor bearing.
Gents - The sealed bearing on the non-belt end of my New Holland 918L appears to be shot. It seemed to have frozen briefly when I started to mow after 6 weeks of non-use, and then after 20 minutes of use, it smoked and I shut down the operation. I've ordered a new bearing from Messick, but am not sure how I punch the old bearing out and position the rotor to put the new bearing in. Do I have to get under the housing, or should I try to rotate the mower on its back, or partially so. Also, do I have to rig a jig to keep the rotor in place?
Gents - The sealed bearing on the non-belt end of my New Holland 918L appears to be shot. It seemed to have frozen briefly when I started to mow after 6 weeks of non-use, and then after 20 minutes of use, it smoked and I shut down the operation. I've ordered a new bearing from Messick, but am not sure how I punch the old bearing out and position the rotor to put the new bearing in. Do I have to get under the housing, or should I try to rotate the mower on its back, or partially so. Also, do I have to rig a jig to keep the rotor in place?