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Old 05-14-2007, 09:50 AM   #1
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Thumbs up 2 SPEED GEARBOX

Hi I was just wondering if any one out there knew how a 2 speed gearbox works. I have a 2 speed box on my car but not sure if it actually changes gears when driven fast.

Many Thanks.
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Old 05-14-2007, 01:17 PM   #2
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A typical two speed clutch works off of a centrifigal (spelling?) clutch.
The second speed spur gear "free spins" until enough rpms are reached to engage the clutch. At that time the second speed engages.

The clutch engagement is dependant upon two things:
1. How tight the tension is on the springs that allow the clutch shoes to spread apart.
2. The engine providing enough rpms to overcome the spring tension.

Reasons why it may not engage or appear to not engage.
1. The engine is running to rich and not producing enough rpms to engage the second gear.
2. The clutch springs are too tight causing late engagement or none at all.
3. The clutch springs are too loose and it is actually in second gear all the time.

You can typically tell when a two speed works...the car actually looks like it goes into a second gear and often you can hear it change engine pitch a little.
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Old 05-14-2007, 02:47 PM   #3
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You should be able to hold the car and feel the it shift.....
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Old 05-15-2007, 12:56 AM   #4
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I'm having the same problem on one of my cars. I haven't got a parking lot big enough to try it out. Is it OK to hold the car up and give it full throttle ? I was always under the impression that doing this could damage the engine and conrod.
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Old 05-15-2007, 01:22 AM   #5
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Thank you all very much. The info you have given me explains alot of stuff.
Once again thanks
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Old 05-15-2007, 03:43 AM   #6
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Quote:
Originally Posted by 32819toon
I'm having the same problem on one of my cars. I haven't got a parking lot big enough to try it out. Is it OK to hold the car up and give it full throttle ? I was always under the impression that doing this could damage the engine and conrod.
hi...i think its normal to give it full throtlle just for a split second...just to feel the 2nd gear/speed shifting...and yes prolong full throt would decreased your engine life...
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Old 05-15-2007, 04:00 AM   #7
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Quote:
Originally Posted by rcabj
hi...i think its normal to give it full throtlle just for a split second...just to feel the 2nd gear/speed shifting...and yes prolong full throt would decreased your engine life...
Would a split second be enough to engage 2nd gear ?
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Old 05-15-2007, 09:46 PM   #8
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Quote:
Originally Posted by 32819toon
Would a split second be enough to engage 2nd gear ?
the 2 speed should already shift when ur on full throtthle, at this stage, a second or so u should already release the throttle. if it still not shifting readjust your 2speed tension, fine tune on the track. also make sure your engine tuning is at it's best.
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Old 05-16-2007, 01:10 AM   #9
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Thanks rcabj - I'll give it a go. I think it needs fine tuning as I haven't have the opportunity to do it properly.
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Old 05-16-2007, 02:08 AM   #10
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ur welcome...good luck
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