Index to Hermit's 650 Triumph Gearbox Articles
Here is a listing of articles on assembling, indexing, and maintaining the Triumph unit 650 4-speed gearbox.
These how-to articles pertain to 1969 and other 60s Triumph 650 4-speed gearboxes using plunger and spring.
If you're researching a Triumph 5-speed gearbox, or a gearbox using a leaf-spring instead of the plunger,
read John Healy's Britbike.com posts on Leaf-spring and 5-speed gearboxes.
Triumph 4-Speed Gearbox Animation
Triumph 4-Speed Gear Cluster Animation - Front View
A Hermit.cc exclusive.
The photo animation shows all the configurations of the complete gear cluster and camplate for all four gears and neutral. Photo illustrations show the flow of power through the gear cluster for all gears, and User can display descriptions, specifications, and part numbers for all the gears.
Note: Please be patient. Animations begin only when completely loaded. Worth the wait on all but extremely slow connections.
Triumph 4-Speed Gear Cluster Animation - Rear View
Same great photo animation and info, but viewed from the rear.
Assembling the Triumph 4-Speed Gearbox
Triumph Unit 650 4-Speed Gearbox Assembly Made Easy
A step-by-step, photo-illustrated tutorial on the clever way Hughie Hancox stuffs a Triumph unit 650 gearbox. It just doesn't get any easier than this! I'm laughing the whole time I'm doing it this way - how can it
be so easy!
Indexing the Triumph 4-Speed Gearbox
How to Index the Triumph Unit 650 4-Speed Gearbox
Indexing the Triumph gearbox when replacing the inner gearbox cover is notoriously tricky, but it doesn't have to be. This tutorial makes it a snap! Whether you want to index in first gear, fourth gear, or neutral between 2nd & 3rd, the photos and text will show you exactly how to get it right. Maybe even the first time!
Triumph 4-Speed Gearbox Plungers, Holders, Springs and Camplates
The Spring Report - Mike James
Mike James took a deep dive into Triumph unit 650 gearbox plunger springs and came up with this detailed and superbly illustrated investigation of springs, plungers, plunger holders, and gearshift camplates, with special attention paid to the raft of changes made 1968-1970. Learn the difference between spring rate and spring force and why it matters. A must-read for those interested in a deeper understanding of these parts and how well they play together in various combinations. (PDF, 8.5mb)
Triumph 4-Speed Gearbox Reference Photos
Triumph 650 Gearbox Reference Photos
Photo illustrations of all the Triumph gearbox parts, including the shafts, the gears, the gear shifting forks, the camplate, and plunger. Includes comparative photos of old and new parts.
Triumph 4-Speed Gearbox Assembly: Three Methods
Triumph Gearbox Assembly Methods Comparison
There are many ways to put a Triumph 650 gearbox back together. Here's a side-by-side comparison of three methods: the Triumph workshop manual, Haynes, and the master himself, Hughie Hancox. Hint: You only need Hughie's method, linked to above.
"Bonnie Ref" Gearbox Section
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The Bonnie Ref" Gearbox Section
A comprehensive guide to the Triumph 650 4-speed gearbox. In addition to maintaining, toubleshooting, tearing down, inspecting, and reassembling the gearbox, you'll find illustrations, diagrams, specifications, factory bulletins, links to motorcycle forum gearbox discussions as well as other resources and much more!
Triumph 650 Gearbox Thrustwasher Locating Peg Repair
Thrust Washer Locating Peg Repair
When a thrust washer spun in Bonnie's gearbox it damaged one of the layshaft's thrust washer locating pegs badly enough to warrent its replacement. A tricky operation considering the required precision. It was my good fortune to have the work done by a locally renowned machinist extroidinair using a jig he devised for the job. All in less than an hour. Thanks, Bob!
A Useful Engine Base
A Plywood Engine Base
I made this plywood engine base to help facilite pressing in Bonnie's drive side layshaft needle bearing with what I believe was a 60-ton hydraulic press. I had so much anxietly about the operation that I forgot to take a photo of pressing it in. This base is also great for transporting an engine securly.
Specifications for Bonnie's Gearset
Effects of Modern Gear Oil on Yellow Metals: An Experiment
Gear Oil & Yellow Metals Experiment
Opinions differ about the safety of using GL5 gear oils in old motorcycle gearboxes with their bronze bushes and thrust washers. See the results of Hermit's 2-year gear oil experiment. Who you gonna believe? Me or your own lyin' eyes? Keep an open mind, now.
John Healy on Triumph 5-Speed & Leaf-Spring Gearboxes
These Britbike.com posts by John Healy, Triumph moderator and renowned Triumph expert, offer valuable insights and tips on assembling and indexing 5-speed leaf-spring gearboxes. The Master speaks.
Indexing Triumph 5-Speed Gearbox Help
Great info and tips on indexing the Triumph 5-speed, straight from the cream of the crop boys and gals at Triumphrat.net.
Kevin Roberts' Triumph 5-Speed Gearbox Restoration and Upgrade Thread
Kevin Roberts' great thread on restoring and upgrading his 5-speed gearbox using Buckshot's plunger conversion kit. Lots of photos, explanations, comments from the peanut gallery. Great article, educational, esp 5-speed owners.
