RUNAMUCK Posted May 30, 2012 Share Posted May 30, 2012 I have the gearbox from my datsun in one million peices atm. I've butchered a low kms four speed, to plunder the low kms gears, and synchro/blocker rings. I even sourced a manual with the correct pictures etc. (Much needed, since it's been almost 5 months since I tore it down) Anyhoo, I was talking to a bloke at work. He reckoned a mod they always used to do back in the day, was remove some of the "teeth" from around the outside periphery of the brass syncho ring. He was quite insistant that it made the selector ring more willing to go into gear, as less teeth means less resistance against the selector ring as it engages the next gear. He actually described it as being like "sucking" it into gear. He reckons it was a mod they always used to do to esky's. Now, I'm all for modifying shit to make it bigger better faster and more. And even a monkey like me could "cull" a few of those teeth. BUT, this is going to be the absolute last time I touch this gearbox. Also, I've never heard of this modification before. So, enlighten me with your pearls of wisdom, oh ye knowers of shit. Quote Link to comment Share on other sites More sharing options...
keltik Posted May 30, 2012 Share Posted May 30, 2012 Gearboxes are fucking evil works of magic. Personally, I've also never heard of this. I wouldve thought resistance to getting into gear was better fixed by changing oil grades than cutting bits out. Quote Link to comment Share on other sites More sharing options...
Llama Posted May 30, 2012 Share Posted May 30, 2012 By removing some of the 'teeth' from the syncro ring (dog clutch) you will indeed probably make it easier to change gear. However the problem becomes that depending on how many you remove, it might be possible to engage the gear to the shaft without yet having completely matched the speed of the shaft and gear. This will result in a bit of jerking, which won't be good for the gears (although you're more likely to shear the dog clutch teeth first). You might also get some slipping back and forth as you change from accelerating to coasting and back, also not good for the teeth. This is if your gearbox is like the syncro ones I've seen, and I'm kinda assuming that you'd remove at least every second tooth from the dog clutch. That being said, I have never actually heard of this mod before. Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted May 31, 2012 Author Share Posted May 31, 2012 It's only the teeth on the blocker ring, not the actual gear itself. And when the selector ring is actually fully engaged, the "energiser lugs" (aka, those wee thingee's which fly out in all directions when you remove the selector ring) actually disengage from the blocker ring. While they dont allow the blocker ring to rotate, they do actualy release it from contact with the tapered synchro ring journal on the engaged gear itself. Quote Link to comment Share on other sites More sharing options...
Hemi Posted May 31, 2012 Share Posted May 31, 2012 not sure about the letting it into gear part but i would never recommending any of the engaging teeth from the gearbox because i have seen them peen off and i know its a low possibility but if you lost all of them then youd have no synchro function/ double clutching yo' Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted May 31, 2012 Author Share Posted May 31, 2012 When I drained the oil, the lugs which drive the blocker rings came out with the oil. So for a good year or more, the blocker rings on 2-3 had been free wheeling. The whole way up to nats and back they were crunchy as fuck. So I just changed gears harder. Which is why the roll pin on the selector fork shore off I suspect. Quote Link to comment Share on other sites More sharing options...
Hemi Posted May 31, 2012 Share Posted May 31, 2012 man bart you NEED to watch fast and furious bud , there are some ace tips for hard driving in that movie ! . Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted May 31, 2012 Author Share Posted May 31, 2012 hahahaha. despite having heard of double clutching, I don't actually know what it means. I don't see how it can be faster than just kicking the clutch pedal for an instant, and smashing the next cog. Quote Link to comment Share on other sites More sharing options...
Hemi Posted May 31, 2012 Share Posted May 31, 2012 it does work instead of making the synchro work nuts get make the shaft speeds to match .. you help it by bringing the shaft speeds closer together. so instead of waiting the 1.5 sec for the synchro to match speeds you can double clutch and have its just go stright into the next gear with minimal synchro pwnage in that same time, it just feels faster and there is less jerking as the rest of the drivetrain is matched . thats a shit explaination , drive a roadranger and it becomes very clear very quick that mashing gears is not the way of gearbox enlightenment Quote Link to comment Share on other sites More sharing options...
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