Where to Find the Allis Chylers 80R Sickle Mower Operator Manual (and Why It Matters)
I spent three years trying to figure out why my 80R would cut poorly at PTO speed, only to realize I was running the wrong sickle clearance for the crop density. The manual has the answer in six pages, but getting your hands on a clean copy of the Allis Chylers 80r Sickle Mower Manual can be a pain. Most scanned PDFs online are blurry, missing pages, or rotated sideways. I found a decent one on tractorsforum.com's archive section and also pulled a factory reprint from eBay for about $12. The eBay copy had better reproduction of the diagrams, which matters when you're trying to read part numbers for the drive gearbox. The manual covers three main systems: the sickle drive mechanism, the cutterbar assembly, and the PTO shielding. It walks through adjustments, lubrication intervals, and troubleshooting charts. The section I use most is the sickle sharpness and gap adjustment chart. It tells you to run 1/16-inch gap between the knife and guard at the cutting edge when mowing dry grass, and up to 3/32-inch for thick, damp growth. People ignore that chart and just set the gap by eye, then wonder why they're shredding the crop instead of cutting it. The lubrication schedule in the manual is critical. It calls for grease fitting on the sickle drive gearbox every 8 hours, and oil changes in the gearbox every season. I skipped the oil change on my first year and ended up with metal shavings in the old oil. That cost me a $200 gearbox rebuild I could have avoided.
How to Use the Manual for Maintenance
Start with the PTO shaft inspection. The manual has a torque spec for the PTO mounting bolts. It says 65 foot-pounds. I used an impact wrench and stripped two bolts because I didn't trust the spec and cranked them too hard. A torque wrench fixed that. After that, check the shear bolt settings. The manual lists the correct shear bolt grade for different operating conditions. Using a higher-grade bolt than specified is a common mistake. It prevents the safety feature from working when the sickle hits a rock. The sickle replacement procedure is straightforward if you follow the manual's sequence. You loosen the hold-down bolts, remove the old knife, clean the contact surfaces, and reinstall with the arrow on the knife pointing toward the drive end. I once installed a knife backward because I didn't read that part carefully. The mower vibrated so badly I could hear it from the tractor seat. Took ten minutes to fix once I caught it.
Common Issues the Manual Addresses
The troubleshooting section covers uneven cutting, excessive vibration, and drive slippage. For uneven cutting, the manual points to worn guards or incorrect knife speed. I had a case where the guards were worn at the tips, creating gaps larger than the spec allows. Replacing the guards cured it. The manual gives a wear limit of 0.060 inches at the guard tip. You can check that with a feeler gauge. Vibration usually traces back to a bent sickle or loose bearings in the drive gearbox. The manual includes a procedure for checking bearing play with a dial indicator. I don't own a dial indicator, so I used a pryers method the manual mentions as a rough check. It's not as accurate, but it gets you in the ballpark. Drive slippage often means the drive belt is stretched or the tension spring is weak. The manual has a belt tension specification measured with a deflection gauge. If you don't have one, you can press on the belt midway between pulleys. It should deflect about half an inch with moderate finger pressure. More than that, and you need a new belt or a tension spring replacement.
Get the Full Details
Where to Download or Buy the Manual
There isn't one official digital source from Allis Chylers anymore since the brand is dormant. The best free options are on tractor manual websites like manualsonline.com and tractorhouse.com. They host scanned copies that are readable but sometimes compressed. For a higher-quality version, TractorParts.com sells reprints for around $15. If you want the complete shop manual with exploded diagrams and part numbers, expect to pay $25 to $35. The part number section alone is worth it if you're rebuilding the cutterbar. I keep a printed copy in my toolbox because PDFs on my phone are hard to read near the mower when it's dirty. The paper version survives oil splashes better. I also bookmark the direct PDF links in my browser so I can pull them up quickly during field repairs.
What the Manual Doesn't Cover Well
The manual is solid on adjustments and maintenance, but it's thin on advanced diagnostics. For example, it doesn't explain how to diagnose a worn output shaft in the gearbox beyond listening for noise. I learned that one from a mechanic friend who took apart three gearboxes before finding the worn bearing. The manual tells you to replace the whole gearbox assembly if there's abnormal noise. That's expensive and often unnecessary if the bearing is the only problem. Another gap is the lack of detailed instructions for converting the mower to different cutting widths or configurations. If you're modifying the setup, you'll need to figure things out yourself or ask in forums. The manual assumes a stock configuration.
Final Thoughts
The Allis Chylers 80R is a simple machine. The manual reflects that. It's not fancy, but it covers everything you need to keep it running. Get a copy, read the adjustment sections before you touch a tool, and follow the lubrication schedule. Your mower will cut cleaner and last longer. If you find a good PDF link, share it where you found it so the next person doesn't have to hunt as hard.
