ZF-Hurth V Drive Flexible Couplings

R&D Marine

Part Number: 910-055



    • Description

      The R&D Marine Flexible Coupling consists of a flexible disc molded with a Polyester Elastomer. The disc gives clearance for bolt heads, and is able to flex freely to take up any temporary misalignment of the engine and shaft, due to flexing of the boat structure or the engine moving on its mount. Forward thrust is taken in compression on the disc between the two half couplings and reverse thrust is taken again in compression on the disc between the two fail safe straps. In the unlikely event of a severe impact, the steel straps make the coupling fail safe and ensure drive is maintained both forward and reverse.

      Reduce Engine Noise & Transmission Vibration
      Staggered bolts enable the element to isolate vibrations and compensate for some misalignment.

      Reduces Costly Transmission Repairs
      Absorbs shock loads due to hard gear changes.

      Fits Most Major Transmissions
      For engines 5 to 1,500 horsepower. Fits brands such as Borg Warner, ZF-Hurth, Twin Disc, Volvo, Yanmar, Technodrive and more!

      Under Compression Load In Both Forward & Reverse
      The aft steel strap bolted to transmission acts as a backing plate to prevent reverse thrust from pulling the element apart.

      Quick & Easy Installation
      The R&D Marine Flexible Coupling requires no machining and comes supplied with bolts to connect between the two existing shaft flanges.

      Extremely Durable
      Impervious to salt water, diesel and lubrication oils. The Flexible Couplings are made from a polyester elastomer which is not affected by salt water, diesel or lubrication fluids.

      Fail Safe Design
      A fail safe design is incorporated in the R&D Flexible Shaft Coupling that prevents the two couplings from pulling apart in the event of an impact or element failure, whereas other couplings such as the Globe Rubber Drivesaver does not. This fail safe design is accomplished by using two steel straps and thru-bolts going into both the shaft coupling and transmission output flange. The aft steel strap is bolted to the transmission output flange and the front strap is bolted the shaft coupling. In the event of an impact the aft steel strap (bolted to the transmission) will catch the front steel strap (bolted to the shaft coupling) and prevent the drivetrain from pulling apart. The R&D element will absorb the shock load (reducing or eliminating damage to the transmission) and will maintain contact between the two couplings. The steel straps also keep the R&D Flex-Coupling under a compression load in both forward AND reverse operation (the aft strap bolted to the transmission acts as a backing plate).

      R&D Marine Flexible Shaft Coupling fail safe design

      Machined Not Molded
      The Drivesaver is molded while the R&D Flexible Shaft Coupling is machined. Both designs suggested that you first set your alignment by drawing the two couplings up to each other and then add the flex-coupling. The machined part will have MUCH tighter tolerance than a molded part.

      Checking Alignment
      The R&D Flexible Shaft Coupling allows for inspection of alignment after the element is bolted in place. There is one bolt head that is machined and painted red. After the R&D Flexible Shaft Coupling is bolted into place, a feeler gauge can be slipped between the red bolt head and the coupling. This process is repeated with the same bolt four times at 90-degree intervals by rotating the shaft. If the gap is within .010” (0.25mm), the engine is accurately aligned.

      Special Orders

      We keep all the common R&D Marine Flexible Couplings in stock, however for a few of the less common sizes will have to be special ordered. Special Order Items will take approximately 2 to 3 weeks to ship out.

    • Flex Coupling Specifications
      Gearbox Flange Dimensions Flexible Coupling Details
      Flexible Coupling Manufacturer Diameter
      inches / mm
      # of Bolts Diameter of Holes
      inches / mm
      Bolt Pitch Circle
      inches / mm
      Register
      inches / mm
      Diameter
      inches / mm
      Length
      inches / mm
      Bolt Diameter HP per 100 RPM
      hp / kW
      Ref
      910-001 B/W, PRM, ZF-Hurth, Technodrive 4 / 101.6 4 0.39 / 10 3.25 / 82.55 2.5 / 63.5 4.5 / 114.3 1.28 / 32.5 M10 5 / 3.73
      910-002 Yanmar 4 / 101.6 4 0.39 / 10 3.07 / 78 1.97 / 50 4.5 / 114.3 1.28 / 32.5 M10 3 / 2.24
      910-003 B/W, PRM, ZF-Hurth, Twin Dsic 5.75 / 146 6 0.5 / 12.7 4.75 / 120.6 3 / 76.2 6 / 152.4 1.87 / 47.5 1/2 UNF 20 / 14.92 X O
      910-004 B/W, PRM, ZF-Hurth 4 / 101.6 4 0.39 / 10 3.25 / 82.55 2.5 / 63.5 4.5 / 114.3 1.4 / 35.6 M10 8 / 5.97
      910-005 Paragon 4 / 101.6 4 0.38 / 9.7 3.25 / 82.55 2.63 / 66.7 4.5 / 114.3 1.35 / 34.5 3/8 UNF 7 / 5.22
      910-006 Twin Disc, ZF-Hurth 5.75 / 146 6 0.63 / 16 4.75 / 120.6 3 / 76.2 6 / 152.4 1.87 / 47.5 1/2 UNF 20 / 14.92 O X O
      910-007 Volvo 4 / 101.6 4 0.39 / 10 3.15 / 80 2.36 / 60 4.5 / 114.3 1.72 / 43.7 M10 3 / 2.24
      910-009 B/W, PRM, ZF-Hurth, Volvo 5 / 127 4 0.44 / 11.2 4.25 / 107.9 2.5 / 63.5 5.63 / 143 1.77 / 45 7/16 UNF 13 / 9.69 X O
      910-012 Yanmar 5 / 127 4 0.39 / 10 3.93 / 100 2.56 / 65 5.31 / 135 1.77 / 45 M10 10 / 7.46
      910-013 Bukh 3.54 / 90 4 0.32 / 8.1 2.93 / 74.5 1.85 / 47 4.5 / 114.3 1.28 / 32.5 M8 3 / 2..24
      910-014 B/W, PRM, ZF-Hurth, Technodrive 4 / 101.6 4 0.39 / 10 3.25 / 82.55 2.5 / 63.5 4.5 / 114.3 1.28 / 32.5 M10 3 / 2.24
      910-015 Self Change 350HD 8.75 / 222.2 6 0.44 / 11.2 7.5 / 190.5 6 / 152.4 8.75 / 222.2 1.75 / 44.5 7/16 UNF 43 / 32.1 O
      910-016 Self Change 700HD 10.25 / 260.4 6 0.63 / 16 9 /228.6 6 / 152.4 10.88 / 276.4 2.28 / 58 5/8 UNF 65 / 48.47 X O
      910-017 Twin Disc 7.25 / 184.2 6 0.75 / 19 6 /152.4 3.75 / 190.5 7.5 / 190.5 2.39 / 60.7 5/8 UNF 40 / 29.84 O X O
      910-018 PRM 7.25 / 184.2 6 0.63 / 16 6 / 152.4 3.75 / 190.5 7.5 / 190.5 2.39 / 60.7 5/8 UNF 40 / 29.84 X O
      910-019 Volvo 4 / 101.6 4 0.39 / 10 3.15 / 80 2.36 / 60 4.5 / 114.3 1.28 / 32.5 M10 3 / 2.24
      910-020 Volvo 4 / 101.6 4 0.39 / 10 3.15 / 80 2.36 / 60 4.5 / 114.3 1.28 / 32.5 M10 5 / 3.73
      910-021 Endfield, Sonic 4 / 101.6 2 0.44 / 11.2 3 / 76  - 4.25 / 108 1.64 / 41.7 7/16 UNF 2.5 / 1.87
      910-022 Twin Disc 9 / 228.6 8 0.89 / 22.6 7.5 / 190.5 6 / 152.4 8.75 / 222.2 1.75 / 44.5 1/2 UNF 65 / 48.47 O X O
      910-024 Twin Disc 10.5 / 266.7 8 1 / 25.4 8.75 / 222.2 5 / 127 10.88 / 276.4 2.23 / 56.7 5/8 UNF 85 / 63.38 O X O
      910-025 B/W, PRM, ZF-Hurth, Twin Disc 5.75 / 146 6 0.5 / 12.7 4.75 / 120.6 3 / 76.2 6 / 152.4 1.96 / 49.8 1/2 UNF 28 / 20.88 X O
      910-026 Twin Disc 5.75 / 146 6 0.63 / 16 4.75 / 120.6 3 / 76.2 6 / 152.4 1.96 / 49.8 1/2 UNF 28 / 20.88 O X O
      910-027 ZF W320 320 A 8.86 / 225 8 0.67 / 17 7.72 / 196 5.51 / 140 9 / 228.6 1.75 / 44.5 1/2 UNF 65 / 48.47 O
      910-028 Bukh 3.54 / 90 4 0.32 / 8.1 2.93 / 74.5 1.85 / 47 4.5 / 114.3 1.28 / 32.5 M8 5 / 3.73
      910-029 B/W, ZF-Hurth, Volvo 5 / 127 4 0.44 / 11.2 4.25 / 107.9 2.5 / 63.5 5.63 / 143 2.06 / 52.4 7/16 UNF 20 / 14.92 O
      910-030 11.5 / 292.1 8 1 / 25.4 9.75 / 247.6 6 / 152.4 11.5 / 292.1 2.3 / 58.4 5/8 UNF 120 / 89.48 O X O
      910-032 B/W, PMR, ZF-Hurth, Twin Dsic 5.75 / 146 6 0.5 / 12.7 4.75 / 120.6 3 / 76.2 6 / 152.4 2.18 / 55.4 1/2 UNF 37 / 27.6
      910-033 Twin Disc, ZF-Hurth 5.75 / 146 6 0.63 / 16 4.75 / 120.6 3 / 76.2 6 / 152.4 2.18 / 55.4 1/2 UNF 37 / 27.6 O
      910-034 Open Center V Drive 52mm Bore 5 / 127 4 0.44 / 11.2 4.25 / 107.9 2.5 / 63.5 6.38 / 162 1.77 / 45 7/16 UNF 12 / 8.95 #
      910-035 13.38 / 340 8 1 / 25.4 11.63 / 295.3 6 / 152.4 13.7 / 348 4.25 / 108 5/8 UNF 160 / 119.3 O
      910-036 Twin Disc 5 / 127 4 0.39 / 10 4.13 / 104.8 2.5 / 63.5 5.63 / 143 1.77 / 45 M10 10 / 7.46
      910-037 Yanmar 5.12 / 130 4 0.48 / 12.3 4.25 / 107.9 2.5 / 63.5 5.63 / 143 2.01 / 51.1 7/16 UNF 13 / 9.69
      910-038 Taipeoungyang TK 250 7 / 178 6 0.56 / 14.3 5.98 / 152 3.94 / 100 7.5 / 190.5 2.49 / 63.3 M14 55 / 41
      910-039 Twin Disc 7.25 / 184.2 6 0.75 / 19 6 / 152.4 3.75 / 190.5 7.5 / 190.5 2.49 / 63.3 5/8 UNF 55 / 41 O
      910-040 PRM 7.25 / 184.2 6 0.63 / 16 6 / 152.4 3.75 / 190.5 7.5 / 190.5 2.49 / 63.3 5/8 UNF 5 /41
      910-041 11.5 / 292.1 8 1 / 25.4 9.75 / 247.6 6 / 152.4 11.5 / 292.1 2.3 / 58.4 5/8 UNF 140 / 104.4 O
      910-042 DONG-I DMT 170L 11.3 / 287.2 6 0.98 / 25.1 9.45 / 240 6.3 / 160 11.5 / 292.1 2.3 / 58.4 5/8 UNF 90 / 67 O
      910-043 Yanmar 4 / 101.6 4 0.39 / 10 3.07 / 78 1.97 / 50 4.5 / 114.3 1.28 / 32.5 M10 5 / 3.73
      910-044 B/W, PRM, ZF-Hurth, Volvo 5 / 127 4 0.44 / 11.2 4.25 / 107.9 2.5 / 63.5 5.6 / 143 1.77 / 45 7/16 UNF 8 / 5.97
      910-045 13.38 / 340 8 1 / 25.4 11.63 / 295.3 6 / 152.4 13.7 / 348 4.25 / 108 3/4 UNF 230 / 171.5 O
      910-046 Allison M25 9 / 228.6 8 0.75 / 19 7.5 / 190.5 6 / 152.4 8.75 / 222.2 1.75 / 44.5 1/2 UNF 65 / 48.47 O
      910-047 Dong-I DMT 260H 11.5 / 292.1 6 0.826 / 21 9.45 / 240 5.9 / 150 11.5 / 292.1 2.3 / 58.4 5/8 UNF 90 / 67 O
      910-048 Twin Disc MG 5111 SC 9 / 228.6 6 (8) 0.89 / 22.6 7.5 / 190.5 6 / 152.4 8.75 / 222.2 2.47 / 62.7 1/2 UNF 65 / 48.47 O X O
      910-049 ZF 325-1A Volvo Flange 8.07 / 205 10 0.71 / 18 6.69 / 170 5.51 / 140 8.78 / 223 4.88 / 124 M18 75 / 56
      910-050 Twin Disc 510A/5114A 9 / 228.6 8 0.89 / 22.6 7.5 / 190.5 6 / 152.4 9 / 228.6 4 / 101.6 1/2 UNF 85 / 63.38 O
      910-051 Twind Disc MG 521 11 / 279.4 8 0.75 / 19 9.5 / 241.3 6 / 152.4 11.25 / 260.4 2.3 / 58.4 5/8 UNF 120 / 89.48 O
      910-052 2F, 220A, Lister, Twin Disc 502 4.75 / 120.7 6 0.44 / 11.2 3.88 / 98.5 2.5 / 63.5 5.94 / 150.9 2.75 / 69.9 7/16 UNF 10 / 7.46
      910-053 Dong-I DMT 150H 8.58 / 218 6 0.79 / 20 7.09 / 180 5.51 / 140 8.75 / 222.2 1.77 / 45 1/2 UNF 48 / 35.8 O
      910-054 Open Center V Drive 58mm Bore 5.75 / 146 6 0.5 / 12.7 4.75 / 120.6 3 / 76.2 6.77 / 172 1.87 / 47.5 1/2 UNF 24 / 17.9
      910-055 Open Center V Drive 52mm Bore 5 / 127 4 0.44 / 11.2 4.25 / 107.9 2.5 / 63.5 6.38 / 162 1.77 / 45 7/16 UNF 7 / 5.2 #
      910-057 B/W, Hurth, Volvo 5 / 127 4 0.44 / 11.2 4.25 / 107.9 2.5 / 63.5 5.63 / 143 2.06 / 52.4 7/16 UNF 25 / 18.64
      910-058 Dong-I DMT 70T, 90T, 100T 7 / 178 6 0.63 / 16 5.98 / 152 3.94 / 100 7.5 / 190.5 2.49 / 63.3 5/8 UNF 55 / 41
      910-059 Volvo 4 / 101.6 4 0.39 / 10 3.15 / 80 2.36 / 60 4.5 / 114.3 1.4 / 35.6 M10 8 / 5.96
      910-060 TMP 4.44 / 112.8 2 0.44 / 11.2 3.19 / 81 - 4.44 / 112.8 1.5 / 38.1 7/16 UNF 3.25 / 2.42
      910-061 Open Center V Drive 52mm Bore 5 / 127 4 0.44 / 11.2 4.25 / 107.9 2.5 / 63.5 6.38 / 162 2.07 / 52.6 7/16 UNF 19 / 14.16
      910-062 DONG-I DMT 140H 7.8 / 198 6 0.63 / 16 6.69 / 170 5.12 / 130 8.27 / 210 1.9 / 48.2 M16 63 / 47
      910-063 Open Center V Drive 58mm Bore 5.75 / 146 6 0.5 / 12.7 4.75 / 120.6 3 / 76.2 6.77 / 172 2.185 / 55.5 1/2 UNF 32 / 23.8
      910-064 Open Center V Drive 67mm Bore 7.25 / 184.2 6 0.63 / 16 6 / 152.4 3.75 / 190.5 9.06 / 230 2.51 / 63.8 5/8 UNF 50 / 37.3

      O - These couplings are fitted with a shouldered bushing to locate in the gearbox flange.

      O - These flexible couplings have been approved by Bureau Veritas.

      x - These flexible couplings have been approved by Lloyds Register of Shipping.

      # - For the Hurth HBW 150 V Gearbox an adapter 202-351 is required (0.875" long).

      For the IRM 220A Gearbox, we can supply adapter plate 202-384 (2.125" long) and for the Twin Disc 502 Gearbox, adapter plate 202-148 (2.125" long) that bolts onto flexible couplings 910-003, 910-025 or 910-032 and with half coupling 202-037 or 202-054, alternatively clamp type 202-176 or 202-178.

    • How To Select The Right Coupling For You
      1. Engine horse power and engine speed.
      2. Type of gearbox and reduction ratio.
      3. Gearbox flange details. Diameter of flange. Diameter of register. Pitch circle diameter of fixing holes. Size and quantity of holes. (Pitch circle diameter is the distance between the center of the hole at 12 o'clock position to the center of the hole at 6 o'clock)

      Example
      1. Ford 150hp at 2,500 rpm.
      2. Borg Warner Velvet Drive 72C 2:1 reduction.
      3. 5" flange 2,500 diameter register, 4.250 PCD, 4 off holes 0.437 diameter
      To Calculate Power Of Coupling Required:


      Coupling rating needed is 12hp. By looking at the chart below we can determine the coupling required is a 910-009 Borg Warner.

    • Installation Procedure For R&D Marine Couplings
      1. Roughly align engine and stern gear without flexible coupling ie. only two rigid half couplings pushed together.
      2. Bolt "R&D Marine" coupling between the two rigid couplings. Tightening details as below.
      3. Check alignment of engine by placing feeler gauges between RED CONE HEADED BOLT and the rigid half coupling. Repeat for the SAME bolt at 90° intervals by rotating the shaft.
      4. If the gap is the same in all four positions, engine is accurately aligned. Recommended minimum to maximum gap difference: 0.010 inch.
      5. Run installation to bring engine compartment to working temperature.
      6. Re-check torque settings.
      Recommended tightening torque:
      • M8 = 20 ft. lbs.
      • 3/8 UNF = 30 ft. lbs.
      • M10 = 45 ft. lbs.
      • 7/16 UNF = 60 ft. lbs.
      • M12 = 80 ft. lbs.
      • 1/2 UNF 75 ft. lbs.
      • 5/8 UNF = 155 ft. lbs.
      • M18 UNF = 250 ft. lbs.
      • 3/4 UNF = 270 ft. lbs.

Customer Reviews

Based on 4 reviews
100%
(4)
0%
(0)
0%
(0)
0%
(0)
0%
(0)
J
J.
Engine Mounts - Max Load 220 - 440 lbs. - 4" Foot Print - 5/8 UNF / 3.05" / 230 lbs & 175 lbs

New engine installation. Engine supports modified for PYI Rubber mounts.
Sea trials in a few weeks.

J
J.
ZF-Hurth Flexible Couplings - 4" Flange - 450D HSW / 4" / 5 hp

All in place & aligned. Sea trials in a few weeks.
Quick delivery

J
J.
PSS Shaft Seal - for 1" to 2" Shaft of SS Olza

New shaft seal in place. Ready to sail around Palawan.
Quick delivery.

D
D.C.
S/y Maitai

Fantastic service, fast shipment. Thanks a lot

Related Items

Get The Latest News!

Join our newsletter! You'll receive the latest product news, special deals, How-To videos, and the latest PYI news straight to your inbox.