The information in this Service Bulletin advises of reduced service intervals for extended service life of drive chains on combines.
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It is not easy for the operator to determine the actual wear on a chain, which often leads to the unnecessary replacement of chains to ensure the chain does not fail during the next harvest season. Experience proves that in most cases, the replaced chain would be serviceable for another season.
In previous Operator’s Manuals NEW HOLLAND recommended to lubricate drive chains every 100 hours. NEW HOLLAND now consider this service interval to be too long.
To overcome this concern, NEW HOLLAND introduced on CX and CR combines from Model Year 2017 (MY17) onward:
A new service interval of every 10 hours or daily, for the lubrication of drive chains.
AND
A chain wear measuring tool for use on:
1 inch drive chains:
CR high capacity unload drive chain
CR feeder drive chain
¾ inch drive chains:
CX/CR bubble-up drive chain
CX/CR clean grain elevator drive chain
CX/CR standard unloading drive chain
ACTION
PRODUCTION
Both the new drive chain service interval and the chain measuring tool are effective from product identification number:
SERVICE
Unit preparation
NOTE: The four reference points to the unit are the left-hand side, the right-hand side, the front of the unit, and the back of the unit. These reference points apply to someone that faces the direction of travel from a standing position that is behind the unit.
WARNING
Avoid injury!
Before you start any work on the unit, prepare the unit according to the following instructions.
Failure to comply could result in death or serious injury.
Thoroughly clean the area on the unit that pertains to the service instructions for this Service Bulletin.
Park the unit on a hard, level surface.
Apply the parking brake.
Completely lower any attachments to the ground.
Relieve all of the hydraulic system pressure.
Shut down the engine.
Remove the ignition key.
Flip the battery disconnect switch to the OFF position.
Follow any specific instructions that pertain to the unit within the service instructions as necessary.
Service instruction
Chain Wear
Figure 1 depicts a new chain which has 0% wear. See the position of the pin (1) and the bushing (2).
A chain is completely worn when it reaches an elongation of 3%.
NOTE: A chain does not stretch, but elongates due to the wear between bushes (1) and the pins (2).
depicts an elongated chain due to wear between the bushes and the pins.
Most industrial standards state that a chain is completely worn when it reaches 3% elongation. At 3% elongation the chain starts to climb on the teeth of the sprocket, as Figure 3 depicts.
Due to the elongation of the chain , the pitch between the links at the pulling side of the chain (X) is larger than the sprocket pitch (Y). This difference in pitch causes the chain to run at a higher diameter on the sprocket. Rapid sprocket wear results when the chain runs high on the sprocket and will eventually cause the chain to jump over the teeth of the sprocket.
NOTE: To avoid the replacement of the sprockets each time a chain becomes worn, you should replace the chain before the chain reaches 3% elongation.
Chain wear assessment:
From MY17 onwards all flagship CX series and CR series combines will have a chain wear measuring tool 47787305. You will find the chain wear measuring tool in the compartment under the operator’s seat with the Operator’s Manual.
The chain wear measuring tool is double sided. You can use the chain wear measuring tool for:
1 inch drive chains:
CR high capacity unload drive chain
CR feeder drive chain
¾ inch drive chains:
CX/CR bubble-up drive chain
CX/CR clean grain elevator drive chain
CX/CR standard unloading drive chain
The chain wear measuring tool has two wear indication tabs on each side:
The first tab represents 1.5% elongation
AND
The second tab represents 2% elongation
Always check for chain elongation with:
The chain correctly installed on the machine
AND
The chain correctly tensioned
1 Place the hooked end of the measuring tool against the roller (1).
2 Rotate the measuring to down to engage with the chain.
NOTE: If the first tongue of the tool (2) does not fit between the rollers, as Figure 6 depicts, the chain is not elongated to 1.5%. You should be able to run the chain for another season without reaching the 3% maximum elongation.
NOTE: If the first tongue of the measuring tool (2) slides down between the rollers, the chain is elongated between 1.5% and 2%. You can continue to use a chain that has elongation between 1.5% and 2%.
However,NEW HOLLAND recommends that you:
– Purchase a replacement chain, to enable easy replacement when it becomes necessary.
AND
– Periodically check the elongated chain for further elongation.
NOTE: If the second tongue of the measuring tool (3) also slides down between the rollers, the chain is elongated more than 2%. You will not be able to complete a whole season with the same chain, NEW HOLLAND recommends that you replace the chain immediately.
Chain lubrication service interval:
For MY17 combines onwards NEW HOLLAND recommends to lubricate drive chains every 10 hours or daily. Lubricate immediately after work when the chains are warm.
NOTE: This service interval is also applicable for combines prior to MY17.
Use AMBRA HYPOIDE 90/AKCELA GEAR 135 H EP 80W-90 for the lubrication of:
1 inch drive chains:
CR high capacity unload drive chain
CR feeder drive chain
¾ inch drive chains:
CX/CR bubble-up drive chain
CX/CR clean grain elevator drive chain
CX/CR standard unloading drive chain
NOTE: Use biodegradable oils for chain lubrication if you cannot recuperate the spilled oil. In many countries rapeseed oils or other agro‐based lubricants are available.
Whenever possible, apply the lubricant with a hard brush on the inside links of the slack span of the chain as Figure 9 depicts. This application technique:
Enables the centrifugal forces to guide the lubricant between the links of the chain
AND
Provides lubrication to the joints between bushing and pins
NOTE:Always stop the machine and remove the ignition key before you undertake this lubrication procedure.
More repair cases for New Holland machine,please refer to:New Holland Trouble Repair
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