Honda Gearshift Drums and Modifications
OEM Parts
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Honda appears to use just a few different gearshift drum designs across its range of sport bikes. The following table shows the Honda part numbers for the shift detent arms (or assemblies) and the shift detent springs for various bikes:
| Model | Year | Code | Spring, Drum Stopper | Stopper Comp., Drum |
| VFR750FL-P | 1990-93 | RC36 | 24435-MR7-000 | 24430-MR7-000 |
| VFR750FR-V | 1994-97 | RC36 | 24435-MZ7-000 | 24430-MR7-000 |
| VFR400RK-N | 1989-92 | NC30 | 24435-MR7-000 | 24430-MR7-000 |
| VFR750RJ-L | 1988-90 | RC30 | 24435-MR7-000 | 24430-MR7-000 |
| RVF400RR-T | 1994-96 | NC35 | 24435-MR8-900 | 24430-MR7-000 |
| RVF750RR-S | 1994-95 | RC45 | 24435-MW4-000 | 24430-GB2-710 |
| VFR800FIW-1; VFR800/A2- VTEC | 1998- | RC46 | 24435-MW4-000 | 24430-GB2-710 |
| CBR400RRL-R | 1990-94 | NC29 | 24435-MV4-000 | 24430-GB2-710 |
Performance Parts
These shifter parts can become tired and worn over time, contributing to missed shifts. Factory Pro Tuning (San Rafael, CA) offers an upgraded set of parts in their Shift Improvement Kits and Trans Detent Arm Kits. Both kits contain an OEM replacement shift cover gasket and a heavy duty detent return spring, but the Detent Arm Kit "replaces the stock shift detent arm and its riveted disc with a new arm with a low friction MicroBearing assembly." The key to the kits is the stronger detent return spring, which basically forces the rider to shift with slightly more effort, and thus more positively, eliminating missed shifts. The latest Factory Pro innovation is the EVO Shift STAR, which, when combined with the MicroBearing assembly and heavy duty spring used in the Detent Arm Kit, result in "easier foot pressure, quicker shifts and virtually zero missed shifts at any throttle position or rpm you could think of." For more information, visit Factory Pro Tuning. Based on the Honda OEM part numbers, the following table shows which Factory kits should fit which bikes:
| Model | Year | Code | Factory Shift Improvement Kit | Factory Pro Trans Detent Arm Kit | Factory Pro EVO Shift STAR Kit |
| VFR750FL-P | 1990-93 | RC36 | SHFT-HON-08 | SHFT-PRO-HON-08 | |
| VFR750FR-V | 1994-97 | RC36 | SHFT-HON-08 | SHFT-PRO-HON-08 | |
| VFR400RK-M | 1990-92 | NC30 | SHFT-HON-08 | SHFT-PRO-HON-08 | |
| VFR750RJ-L | 1988-90 | RC30 | SHFT-HON-07 | SHFT-PRO-HON-07 | |
| RVF400RR-T | 1994-96 | NC35 | SHFT-HON-?? | SHFT-PRO-HON-?? | |
| RVF750RR | 1994 | RC45 | SHFT-HON-91 | SHFT-PRO-HON-91 | SHFT-EVO-H91-KT |
| VFR800FIW-1; VFR800/A2- VTEC | 1998- | RC46 | SHFT-HON-91 | SHFT-PRO-HON-91 | SHFT-EVO-H91-KT |
| CBR400RRL-R | 1990-94 | NC29 | SHFT-HON-?? | SHFT-PRO-HON-?? | SHFT-EVO-H??-KT |
As you can see, there are some missing part numbers in the table, and if you look really closely, you will see something odd regarding the RC30 part numbers. Even though the RC30 uses the same OEM detent arm and spring as the other VFR750s, it has different Factory Pro part numbers. Well, there's only one other part in the Factory Pro kits, and that is the shift cover gasket... The RVF400R (NC35) uses the same OEM detent arm as the other RC30-based designs, but it has a different OEM spring part number. This may mean that the Factory Pro kit that fits the other bikes will fit--or it might not. (The '94-'97 VFR750FR-V also has a different spring part number, but the same Factory Pro shift kits that fit the earlier 750s still fit...) The NC29 has the same problem: same detent arm as another bike, but different spring. But, if the VFR800 kits do fit, that means the new EVO Shift STAR kit should also fit! (The cover gasket would probably be the wrong one, though.) Hopefully, Factory Pro will update their Web site soon to clear up these mysteries...
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Copyright © VSource.org 1999-2006 [Sources: Factory Pro Tuning and Honda Parts Manuals and Microfiche] |