Forum

[612cc]

Hi
I have been having trouble getting 2nd/3rd gear ot should say i cannot now also seems a long way now to first and a long way down to second
took the outer gearbox cover off and would like some help here please all new terroirty to me , in particular a sketch or phortos would help with hiw the oblong ratchet teeth should look like in 1st/2nd/3rd/4th when in there right place /housing and help welcomed this is all new to me
cheers
kevin

[Tim NZ]

In your case there is not much you can fix by removing the outer cover...


The lay-shaft bushes, shaft, and dogs are worn. Full strip down and specialist repair for the most part.

[binary]

If you can afford it upgrade to a modern 5 speed gearbox and fit it up. Hitchcocks have them. They come with a kit with all you need to fit them. They have right shift ones if your present gearbox is a right shifter. You can fit one on your motorcycle with out having to take the motor out of your frame. I fitted one about 12 months ago now and it has been a wonderful thing. When fitted the gears are evenly spaced and you are always in the right gear when riding around. You use the original clutch plates and the clutch works much better as well.

[Alan R]

------ and that humungus G----------A-------------P between 3rd & 4th has gone ( Hoo---ray !!).. PLUS}-- you use ordinary SAE 90 oil in it and not that crappy "grease" stuff so it's a win-win situation all round..

[Tim NZ]

The 4-speed gap 'tween top and 3rd is bridged by fitting the Close-ratio gear set.


Typically, the Indian gear-box does not leak with oil in lieu of grease.


IF the gear-box develops an oil-leak at the kick-start (it will not be from the k-start but the mainshaft brg cap...) it is usually due to lack of ventilation, which is cured by drilling a wee vent hole in or near the oil filler plug.

[Alan R]

Sorry TIM, will have to take issue with that reply I'm afraid}--- Fitting the close ratio set is a form of mechanical "Smoke and mirrors".....Whilst the gap appears to have been reduced it is only achieved by raising the 1st, 2nd, and 3rd ratios to be closer to the 4th...However the very useful original 1st ratio has now gone...

With regards to leaking then I would suggest that fitting our hosts Sealed Bearing Kit ( 90118 ) would be the better option for our contributor 612cc, especially as you've just indicated a full strip down so that would be the time to do it...The 5-speed box has a conventional construction ie}-- a rotating camplate, short movement sliding gears with dog clutches etc. which any classic motorcycle mechanic can recognise and work on...It can also increase the rate of acceleration.....The 4-speed requires specialist attention --as you rightly identified..It also appears to have more false Neutrals than would seem possible, whilst that Neutral selector lever can play havoc with your right boot !!.

Over the last 10 years I've owned, ridden and maintained 2 x 4 speed and 2 x 5 speed machines...Indeed the current bike is a Bullet '65 and I know which I prefer to have on to-day's modern roads.....BINARY loves the 5-speeder and so do I, but each to their own, eh ??.......

[Tim NZ]

IMHO a road going Bullet (and/or the Twins) needs a 5 speed Gb as much as a snowman needs an electric blanket! The 4spd 'poor-boy' CR option with just the two gears needing to be exchanged, not the Full Set is perfect for street use.


There is no arguing that the 5speed is a far superior design (it is a lot easier to work on too) and if one 'over gears' the bike so that 4th is akin to the 4sp Top, then the drop into 3rd becomes decidedly 'sporting'. Depending on ones riding style???


It will also depends on where one lives and ride? If I had to ride in City traffic, them I would begrudgingly concede the 5sp advantage at crawling speeds. On the open road first gear is of little significance.


For riding that demands excellent low speed tractability I am a dedicated fan of conversion to Twin-plug. (AND retaining the decompressor!) Steady idle at 600/650 rpm and the bike will putt along, clutch fully home, two-up at those rpm. Less ignition advance needed, slight improvement in fuel economy and combustion by-products, and best of all; no detonation issues!


A hell of a lot cheaper and easier than swapping out a Gear-box...




Getting back to the question at hand. A new lay-shaft (the ends of the old shaft will be scored) and 2 new Bronze bushes, run the box with oil, and expect 100,000 trouble free miles. The silly Indians insisting that the box still be filled with grease is a sop back to the early 50's when rubber oil seals were still a work in progress. And the Splines on the main-shaft sleeve gear still under-cut the gear box main bearing. THAT was the main leak path; stopped by a badly fitted FELT washer.


Post 2001 Enfield gear-box's typically DONT leak oil. Much better sealing arrangement at bearings, sprocket, and shaft ends.

[Alan R]

"Many are the roads that lead to Rome" I think.. -- as I said, my comments are made based on practical ownership of both types over a 10 year period BUT--- I didn't have to buy and fit one so yes, the change-over costs may be prohibitive to our colleague...( BINARY seems to have managed ok though..).....The Bullet '65 retains the de-compressor but mine also has electronic ignition with an Irridium plug so no probs with starting, slow running, detonation, etc....All I'm saying is that if you are about to spend a whole load of ££££ or $$$ or whatever on the innards of a 4-speeder then why not put it towards a proven update ??...R/Enfield did........OK then, 'nuff said, back to the thread issue.

[binary]

I fitted a close ratio gear set to my old 4 speed before I bought my 5 speed. I wasted my money on the close ratio gear set. I should have just bought the 5 speed gearbox in the first place. With the 5 speed box while riding around I dont even have to think about the gearbox at all. It has moved into the back ground and now just does its job. I am still amazed at the difference that it has made to my motorcycle.

[stinkwheel]

I wouldn't say it was THAT specialist/difficult to repair a 4-speed box. Take it apart and have a look. Parts are relatively cheap for them depending on how many you need.



There are some pretty detailed diagrams in the "technical notes" section of our hosts website and articles on the workings of the 4-speed box.



The way I do such things is to read as much as possible round the subject and take lots of photographs as I strip it down. Mine was jumping out of first, I replaced two gear clusters, the selector plunger and the ratchet just because I was in there.