sounds like the rear bearing / carrier or a snapring had an issue and let go... there is also a thrust washer that will drop down once that pto shaft is slid out.
here's the exploded diagram of the ind pto model, plus the parts list.
1 1 82847704 HOUSING Housing, Clutch, Repl. C5NNN708B, When replacing C5NNN708B W/C5NNN708C(81817334) on Tractors built prior to production date code 8F26 also use 6 each 1P77573A & C5NNP743B Plates instead of (7) C5NNN744B(81816
2 1 81801963 PISTON Piston, Clutch, Start Year: 01/01/1965
3 1 9849963 O-RING O-RING, -136, 90 Duro, 1.987" ID x .103" Thk, Start Year: 01/01/1965
4 1 C0NN7C000A SEALRING Seal, Clutch Piston Outer, Repl. 1P77513A, Start Year: 01/01/1965
5 1 1P77515B SPRING Spring, Clutch Piston, (C), Start Year: 01/01/1965
6 1 C5NNN757A WASHER Washer, Clutch Piston Spring Retaining, Start Year: 01/01/1965
7 1 C5NNN754A SNAP RING Snap Ring, Clutch Piston Spring Retaining Washer, Start Year: 01/01/1965
8 7 C5NNN744B CLUTCH Disc Assy., Clutch, Years: 01/01/1965-03/31/1968
8 6 C8AP7B442A PLATE Plate, Clutch External Spline, (C), Start Year: 04/01/1968
9 6 C5NNN743A PLATE Plate, Clutch, Years: 01/01/1965-03/31/1968
9 6 C5NNP743B PLATE Plate Assy., Clutch Internal Spline, Start Year: 04/01/1968
10 1 C4TP7B437A PLATE Plate, Clutch Pressure, Start Year: 01/01/1965
11 1 1P77523A RING Snap Ring, Clutch Pressure Plate, (C), Start Year: 01/01/1965
12 2 81809513 SEAL SEAL, 2.375" OD, Oil, Clutch Housing, Start Year: 01/01/1965
13 1 C5NNN783B DISC Washer, Clutch Thrust, Start Year: 01/01/1965
14 1 E9NNN739AA SHAFT Shaft & Bushing Assy., Indep. PTO Clutch Includes: Shaft Plus: 15, Start Year: 01/01/1965
15 1 C5NNN709B BUSHING Bush/Bushing, Start Year: 01/01/1965
16 AR 81805215 WASHER Washer, Clutch Input Shaft .030 (.762mm), Start Year: 01/01/1965
16 AR C5NN7N509B WASHER Washer, Clutch Input Shaft .010 (.254mm), Start Year: 01/01/1965
17 1 C5NNN704B SUPPORT Support, Clutch Brake Housing, No Longer Serviced., Years: 01/01/1965-02/28/1969
17A 1 D8NNN704AA SUPPORT Support Assy., Repl. C7NNN704B, When replacing C7NNN704B (81819063) W/D8NNN704AA (81819063) also replace C5NNN787B(87763140) W/D8NNN787BA (83917386)., Start Year: 01/01/1965
17B 1 83416255 HYD CONNECTOR Connector, 1/2"-20 x 5/16" (Tube) (Replaces 87972S), Start Year: 03/01/1969
18 1 C5NNN701A HOUSING Housing, Clutch Brake, Years: 01/01/1965-02/28/1969
19 4 80681 LOCK WASHER Washer, Lock, 5/16", Start Year: 01/01/1965
20 2 87657 BOLT BOLT, Hex, 5/16"-18 x 1 1/4", G5, Start Year: 01/01/1965
22 1 C9NNN747A ARM Arm Assy., Drive Clutch Brake (Repl. C7NN-N747-C), Start Year: 01/01/1965
23 1 280236 COTTER PIN Pin, Split (Cotter), 1/16" x 1/2", Start Year: 01/01/1965
24 1 73947S PIN Pin, Clevis, 1/4" x 1-3/8", Start Year: 01/01/1965
25 1 D8NNN787BA PISTON Piston, When replacing C5NN-N787-B(87763140) W/D8NN-N787-BA(81817334) also replace C7NN-N704-B(81819063) W/D8NN-N704-AA(83917385)., Start Year: 01/01/1965
26 1 9849109 O-RING O-Ring, .250" ID x .070" Thk, Piston (Small), Start Year: 01/01/1965
27 1 788421 O-RING O-Ring, 1.489" ID x .070" Thk, Piston, Large, Start Year: 01/01/1965
28 1 C5NNN785D SPRING Spring, Drive Clutch Brake (Outer), Start Year: 01/01/1965
28A 1 C5NNB716B SPRING Spring, Drive Clutch Brake (Inner), Start Year: 01/01/1965
29 1 C5NNN784B WASHER Washer, Drive Clutch Brake, Start Year: 01/01/1965
30 1 C5NNN716A RING Snap Ring, 1-5/16" Clutch Brake Spring & Washer, Start Year: 01/01/1965
31 1 C5NNN742A GASKET Gasket, Clutch Brake Plate, Start Year: 01/01/1965
32 1 C5NNN706B PLATE Plate, Clutch Brake, Repl. C5NN-N706-A, Start Year: 01/01/1965
33 AR 81547 LOCK WASHER WASHER, LOCK, 7/16"
34 3 304705S36 BOLT BOLT, Hex, 7/16"-14 x 1 1/8", G5, Start Year: 01/01/1965
35 1 81801988 TUBE Tube Assy., Clutch Valve to Brake Hsg. Support, Start Year: 01/01/1965
36 1 D8NNN797AA HYDRAULIC VALVE Valve Assy., Independent PTO Clutch Repl. C5NNN797C (Ref. 5B 9-17-1T) Includes: Housing Plus: 37-40, Start Year: 01/01/1965
37 1 C5NNN781A SPRING Spring, Valve Detent, Start Year: 01/01/1965
1 72387 BALL BALL, 5/16" Dia, Detent Spring, Start Year: 01/01/1965
39 1 81801976 PISTON Piston, Clutch Valve, Start Year: 01/01/1965
40 AR 81801936 SHIM Shim, Piston Spring .30 Dia. x .030, Start Year: 01/01/1965
41 1 D8NNN775AA SPRING Spring, Clutch Valve, Start Year: 01/01/1965
42 1 C5NNN717B PLUNGER Plunger, Clutch Valve, Start Year: 01/01/1965
43 1 V15713 ROLL PIN Pin, Roll, 1/8" x 7/8", Start Year: 01/01/1965
44 1 87037S94 O-RING O-Ring, .750" ID x .103" Thk, Valve Assy. to Bushing, Start Year: 01/01/1965
45 1 81801879 BUSHING Bush/Bushing, Clutch Valve to Center Housing, Start Year: 01/01/1965
46 1 81801978 BOLT Bolt, Valve Body Spigot, Start Year: 01/01/1965
47 1 81547 LOCK WASHER WASHER, LOCK, 7/16", Start Year: 01/01/1965
48 1 C5NNN793A DISC Washer, Valve Body Spigot, Start Year: 01/01/1965
49 1 81547 LOCK WASHER WASHER, LOCK, 7/16", Start Year: 01/01/1965
50 1 304668S36 BOLT BOLT, HH, G5, 7/16"-14 x 7/8", Start Year: 01/01/1965
51 1 E6NNN728AA CONNECTING LINK Link, Clutch Valve Lever, E6NNN728AA(83956755) has no groove in Shaft for O-Ring, Ref. 52, as did the previous P/N C5NN-N728-C(81815732). This is correct, install O-Ring in same manner. The groove is not necc
52 1 130282 O-RING O-Ring, .489" ID x .070" Thk, Start Year: 01/01/1965
53 AR 280236 COTTER PIN Pin, Split (Cotter), 1/16" x 1/2"
54 1 9672307 CLEVIS PIN PIN, CLEVIS, 1/4" x 3/4", Start Year: 01/01/1965
55 1 81816077 BUSHING Bushing, Clutch Valve Lever, Start Year: 01/01/1965
56 1 C5NNN741F LEVER Lever, Clutch Valve, Replaces P/N C5NNN741B, 4100, Start Year: 01/01/1965
56 1 D2NNN741A LEVER Lever, PTO Clutch Valve, 3550-4400-4410-4500, No Longer Serviced., Start Year: 01/01/1965
57 1 34807S36 LOCK WASHER Washer, Lock, 3/8", Start Year: 01/01/1965
57A 1 88374 BOLT Screw, Cap, HH, G5, 3/8"-24 x 1", Start Year: 01/01/1965
58 1 C5NNN788A TUBE Tube Assy., Clutch Valve to Hydraulic Pump, Start Year: 01/01/1965
59 1 9993141 O-RING O-Ring, 90 Duro, .364" ID x .070" Thk, Start Year: 01/01/1965
60 1 83929950 TUBE Tube Assy., Valve Exhaust Lower (Replaces E1NNN770AA), Start Year: 01/01/1965
61 1 83929949 TUBE Tube Assy., PTO Valve Exhaust Upper (Replaces E1NNN769AA), Start Year: 01/01/1965
62 2 C5NNN790A SEAL Seal, Exhaust Valve, 3/8" I.D. x 1/2" O.D. x .26 (9.525 x 12.7 x 6.604mm), Start Year: 01/01/1965
63 1 81811253 BRACKET Bracket Assy., Exhaust Tube, Start Year: 01/01/1965
63A 1 P0401-542 BOLT Screw, Cap, HH, G5, 1/4"-28 x 1", US, Start Year: 01/01/1965
63A 1 P0401-542 BOLT Screw, Cap, HH, G5, 1/4"-28 x 1", Start Year: 01/01/1965
64 1 D3NN710D SHAFT Shaft & Sleeve Assy., PTO Rear, 30.64", 26T, Replaces P/N C5NN710A, Start Year: 01/01/1965
65 1 D3NN7A693A BEARING ASSY Bearing, Shaft Rear, Start Year: 01/01/1965
66 2 168104 SNAP RING Ring, Snap, #177, Ext, Rear Shaft Bearing, Start Year: 01/01/1965
66 2 BB7045 RING Ring, Lock, Rear Shaft Bearing, No Longer Serviced NH-E., Start Year: 01/01/1965
67 1 81801870 SNAP RING Ring, Snap, Bearing to Center Housing, Start Year: 01/01/1965
69 1 C5NN4N129A GASKET Gasket, Plate, Optional w/#EAF-980-A, Years: 01/01/1965-11/30/1966
69A 1 EAF980A O-RING O-Ring, Cover Seal, Optional w/#C5NN-4N129-A, No Longer Serviced NH-E., Years: 01/01/1965-11/30/1966
69A AR NS NOT SERVICED Refer to Service Bulletin Feb. 1967 (6T), Not Serviced, Start Year: 01/01/1965
70 2 C5NNN737A Tab, Plate Lock, Optional w/#34796-S7, U.S., No Longer Serviced NHNA., Years: 01/01/1965-11/30/1966
70A 4 86729275 LOCK WASHER Washer, Lock, 5/8", Quad Rib, Optional W/#C5NNN737A, Years: 01/01/1965-11/30/1966
70B 1 C5NNN727A Plate, PTO Rear, Years: 01/01/1965-11/01/1966
71 3 377186S43 BOLT Bolt, HH, 5/8"-11 x 1-5/8", No Longer Serviced NHNA., Years: 01/01/1965-11/30/1966
71 1 379625S2 SPARE PART Bolt, HH, 5/8"-11 x 1-5/8", No Longer Serviced., Years: 01/01/1965-11/30/1966
72 2 81547 LOCK WASHER WASHER, LOCK, 7/16", Years: 01/01/1965-11/30/1966
72 4 81547 LOCK WASHER WASHER, LOCK, 7/16", Start Year: 12/01/1966
73 4 9637916 BOLT BOLT, Hex, 7/16"-14 x 1 1/2", G5, Start Year: 12/01/1966
74 1 C5NN733B COVER Cover, No Longer Serviced NHNA., Years: 01/01/1965-11/30/1966
74 1 C5NN733F COVER Cover, Start Year: 12/01/1966
75 1 D9NN703BB GASKET Oil Seal Assy., PTO, Start Year: 01/01/1965
76 1 81801859 COVER Cap, Start Year: 01/01/1965
77 1 C5NNP717B Shroud Assy., Clutch, No Longer Serviced., Start Year: 01/01/1965
78 1 C5NNP744A STOP Stop, Clutch Valve Lever, Start Year: 01/01/1965
79 1 44730S8 SPARE PART Washer, 7/16", NHNA Only., No Longer Serviced., Start Year: 01/01/1965
80 1 379410S2 SPARE PART Bolt, HH, 7/16"-14 x 1-1/2", NHNA Only., No Longer Serviced., Start Year: 01/01/1965
