Chelsea PTO 721 Series Parts Manual
This Chelsea Illustrated Parts List covering the 721 PTO helps you identify the correct gear sets, shifter kits and service parts for your power take-off before you order.
| Models covered | 721 |
| PTO type | Chelsea 700 Series |
| Document | Illustrated Parts List (Chelsea) |
| Length | 12 pages |
| Format | PDF — view below or download free |
What’s inside
- Gear sets & output shaft assemblies
- Shifter & air-shift control kits
- Mounting gaskets & adapter plates
- Housings & cover assemblies
- Seal, bearing & snap-ring kits
- Application & ratio reference tables
- Exploded views with OEM part numbers
Read the manual
This is our interactive copy of the factory manual — part numbers are clickable and every exploded-view callout links to the part. Plain factory PDF if you prefer it.
Chelsea parts & units we stock
Pro Gear and Transmission stocks new, remanufactured and good-used parts for Chelsea PTO units:
Chelsea 721 parts list — every part number linked
This is the bill of materials from the manual above, matched against our own stock. Click any part number to see the listing and current price, or use ▶ Add to drop it straight in your cart. 78 of the 93 lines in this book are parts we carry.
Prices are shown on each product page so you always see the current one. Anything not linked, or marked no longer available, we can still usually source — call (877) 776-4600.
Prefer the book? Download the interactive PDF — same manual, with every part number and every exploded-view balloon clickable.
Bill of Materials — manual page 7
| Item | Part number | Description | Qty | Order |
|---|---|---|---|---|
| 1 | 1-P-337 | Housing, Gearbox call to confirm availability | 1 | |
| 2 | 2-P-721 | Gear, Sliding 19-T | 2 | ▶ Add |
| 3 | 3-P-859 | Drive Shaft, Standard Output (1.250" Dia.) | 2 | ▶ Add |
| 4 | 3-P-205 | Drive Shaft, Standard Input (1.250" Dia.) call to confirm availability | 1 | |
| 6 | 4-P-46 | Spacer | 1 | ▶ Add |
| 7 | 4-P-47 | Spacer | 1 | ▶ Add |
| 9 | 5-P-220 | Gear, Idler no longer available — call for a replacement | 1 | |
| 10 | 9-P-56 | Shaft, Idler call to confirm availability | 1 | |
| 11 | 14-P-15 | Spacer A.R | ▶ Add | |
| 12 | 21-P-67 | Bearing Cap, Open | 2 | ▶ Add |
| 21 | 27-P-9 | Retaining Plate | 1 | ▶ Add |
| 22 | 28-P-191 | O-Ring | 1 | ▶ Add |
| 23 | 28-P-216 | Oil Seal | 4 | ▶ Add |
| 25 | 33-P-64 | Gear, Drive | 1 | ▶ Add |
| 26 | 34-P-16 | Cover Plate call to confirm availability | 1 | |
| 27 | 35-P-8 | Gasket, Shifter Cover (.020" Thick) | 2 | ▶ Add |
| 28 | 35-P-59 | Gasket, Cover Plate | 2 | ▶ Add |
| 29 | 68-P-2 | Name Plate | 1 | ▶ Add |
| 328273X | BEARING CAP SUB-ASSEMBLY, Open (Includes Items 32-32) | 2 | ▶ Add | |
| 32 | 21-P-418 | Bearing Cap (Open) call to confirm availability | 1 | |
| 33 | 550221 | Bearing Cup | 1 | ▶ Add |
| 328274X | BEARING CAP SUB-ASSEMBLY, Closed (Includes Items 36-37) | 2 | ▶ Add | |
| 36 | 21-P-420 | Bearing Cap (Closed) call to confirm availability | 1 | |
| 37 | 550221 | Bearing Cup | 1 | ▶ Add |
| 85 | 378391 | Lockring | 4 | ▶ Add |
| 86 | 378422 | Drive Screw | 2 | ▶ Add |
| 88 | 378430-8 | Capscrew, Hex Head (.375"-16 x .500") | 1 | ▶ Add |
| 89 | 378430-9 | Capscrew, Hex Head (.375"-16 x .875") | 14 | ▶ Add |
| 90 | 378430-10 | Capscrew, Hex Head (.375"-16 x 1.000") | 16 | ▶ Add |
| 92 | 378431-4 | Capscrew, Hex Head (.375"-16 x .500") | 6 | ▶ Add |
| 93 | 379064 | Pipe Plug (.500"-14) | 2 | ▶ Add |
| 95 | 379334 | Oil Level Caution Tag (Shipped Wired to Unit) | 1 | ▶ Add |
| 96 | 500007-24 | Woodruff Key (Ref. Input Shaft) | 1 | ▶ Add |
| 97 | 500007-29 | Woodruff Key (.312" x 1.125") | 4 | ▶ Add |
| 99 | 500166-10 | Welch Plug (.750" Dia.) | 1 | ▶ Add |
| 100 | 500167-1 | Breather Cap no longer available — call for a replacement | 1 | |
| 101 | 500925-1 | Pipe, Street Elbow no longer available — call for a replacement | 1 | |
| 103 | 550218 | Bearing Cup | 2 | ▶ Add |
| 104 | 550397 | Bearing Cone | 2 | ▶ Add |
| 105 | 550437 | Bearing Cone | 2 | ▶ Add |
| 106 | 550439 | Bearing Cone | 2 | ▶ Add |
| 107 | 550532 | Bearing Cone | 2 | ▶ Add |
Parts list (page 8) — manual page 8
| Item | Part number | Description | Qty | Order |
|---|---|---|---|---|
| VIEWX | ||||
| 328826-1X | & 3X AIR SHIFT COVER ASSEMBLY (Includes Items42-66) 1 or | ▶ Add | ||
| 40 | 328826-2X | & 4X AIR SHIFT COVER ASSEMBLY (Includes Items42-66) | 1 | ▶ Add |
| 42 | 11-P-129 | Shifter Shaft | 1 | ▶ Add |
| 43 | 65-P-23 | Cover, Shifter Shaft | 1 | ▶ Add |
| 44 | 32-P-141 | Shifter Fork | 1 | ▶ Add |
| 45 | 34-P-82 | Cover, Shifter | 1 | ▶ Add |
| 328824X | Sub-Assembly | 1 | ▶ Add | |
| 47 | 28-P-61 | O-Ring | 1 | ▶ Add |
| 48 | 28-P-71 | O-Ring | 1 | ▶ Add |
| 49 | 28-P-2500 | O-Ring call to confirm availability | 1 | |
| 50 | 34-P-81 | Cap | 1 | ▶ Add |
| 52 | 38-P-50 | Spring call to confirm availability | 1 | |
| 53 | 65-P-15 | Cylinder | 1 | ▶ Add |
| 54 | 66-P-13 | Piston | 1 | ▶ Add |
| 56 | 378430-9 | Capscrew, Hex Head (.312"-18 x .875") | 2 | ▶ Add |
| 57 | 379102 | Washer, Spring Retainer | 2 | ▶ Add |
| 58 | 379103 | Retaining Ring (N-5000-106) | 1 | ▶ Add |
| 59 | 500897-3 | Shipping Plug no longer available — call for a replacement | 2 | |
| 60 | 35-P-14 | Gasket | 2 | ▶ Add |
| 61 | 378430-9 | Capscrew, Hex Head (.312"-18 x .875") | 2 | ▶ Add |
| 62 | 378447-4 | Capscrew, Socket Head (.312"-18 x .75") | 1 | ▶ Add |
| 63 | 378554 | Poppet Cap | 1 | ▶ Add |
| 64 | 379652 | Indicator Switch (Norm. "ON") | 1 | ▶ Add |
| 65 | 65-P-23 | Cover, Shifter Shaft | 1 | ▶ Add |
| 66 | 378430-4 | Capscrew, Hex Head | 2 | ▶ Add |
| 328388-40X | SHIFT INSTALLATION KIT, Air-O-Matic | ▶ Add | ||
Parts list (page 9) — manual page 9
| Item | Part number | Description | Qty | Order |
|---|---|---|---|---|
| TORQUE TO 16-20 FT LB | ||||
| 2 | KILCX3RAM | METERS TORQUE TO 10-15 FT LB call to confirm availability | ||
| CABLE CONTROL ASS'Y | ||||
| 70 | 328830-1X | SHIFT COVER SUB-ASSEMBLY, Wire Control | 1 | ▶ Add |
| 71 | 328830-1X | SHIFT COVER SUB-ASSEMBLY, Wire Control (Includes Items72-83) | 1 | ▶ Add |
| 72 | 28-P-191 | O-Ring | 2 | ▶ Add |
| 73 | 34-P-74 | Cover, Shifter | 2 | ▶ Add |
| 74 | 37-P-14 | Spring, Poppet | 2 | ▶ Add |
| 75 | 51-P-13 | Lever, Shifter | 2 | ▶ Add |
| 76 | 500365-22 | Flat Washer | 2 | ▶ Add |
| 77 | 328829-1X | Shifter Plate Assembly, Side "X" | 1 | ▶ Add |
| 78 | 328829-2X | Shifter Plate Assembly, Side "Y" | 1 | ▶ Add |
| 79 | 378002 | Ball (.438" Dia.) | 2 | ▶ Add |
| 80 | 500356-10 | Lockwasher | 2 | ▶ Add |
| 81 | 378004 | Flat Washer | 2 | ▶ Add |
| 82 | 379652 | Indicator Switch (Norm "ON") | 2 | ▶ Add |
| 83 | 500409-6 | Capscrew, Hex Head (.312"-24 x .625") | 2 | ▶ Add |
| 110 | 328346-10X | Wire Control Assembly | 1 | ▶ Add |
| 328537 | Parts Bag, Wire Control (Includes Items 113-119) call to confirm availability | 1 | ||
| 113 | 50-P-17 | Bracket | 2 | ▶ Add |
| 114 | 50-P-19 | Bracket, Swivel | 2 | ▶ Add |
| 115 | 378019 | Pivot Pin | 2 | ▶ Add |
| 116 | 378326 | Bushing Nut, Hex | 2 | ▶ Add |
| 117 | 378982 | Spacer, Mtg call to confirm availability | 2 | |
| 118 | 500396-8 | Screw, Hex Head (.250"-20 x .750") | 2 | ▶ Add |
| 119 | 500568-4 | Set Screw, Square Head (.250"-20 x .500") | 2 | ▶ Add |
| 328838X | INSTALLATION KIT, Wire Control | 2 | ▶ Add | |
Part numbers and descriptions are taken from the Chelsea/Parker parts manual on this page. Chelsea® and Parker® are trademarks of Parker Hannifin Corporation; Pro Gear and Transmission is an independent distributor.
Not sure exactly which unit you have? Check our identification guides, or Ask an Expert — send us photos of your data tag and our drivetrain specialists will identify the unit and the exact parts you need. Or call (877) 776-4600.