hey just wondering.... was down on a stretch of empty road so i decided to gun it. well... switching from first to second at about 6.5k rpms, is it a smooth transition? i felt a real hard jerk and kinda like a quick thump noise. i thought it was me but i tried it again and same thing. then i let my friend drive it the same way and it happened again. is this normal? opinions please?

 

It sounds like your popping the clutch too quickly between 1st and 2nd. That thump that you're hearing is your transmission, and that's not a good thing. Keep in mind that with AWD, you're not really going to get wheel spin as you shift between the gears and your tranny will take the brunt instead. Feather the clutch more as you shift between gears.

 

try double clutching, it works for me and now my shifts are nice and smooth.

 

thanks a lot everyone. but i always thought double clutching was useless.... then again.... i hear a lot of different definitions of what double clutching is. what double clutching anyway... a real definition of it.

and RJC..... thanks to you too.... but what do you mean feather the clutch?

thanks again everyone.

 

That 'thump' you hear is the equivalent of a rear differential pinion snubber on a rear-drive car. Under hard acceleration, the nose of the rear diff will rise and contact a cushioned bushing when shifting. It's normal.

Double-clutching is not necessary during upshifts. It does relieve the wear on the transmission synchros during downshifting, however.

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0==WW==0
"…axles of evil…" - george w. bush

 

can anyone tell me what double clutching is?

 

Double clutching=
1. Press clutch down
2. Shift to neutral position
3. Release clutch
4. Press clutch down again
5. Downshift into the gear
For example if you wanted to downshift from 4 to 3, you would follow the above steps to double clutch....

 

The thump you hear is normal, it is the viscous rear differential locking up.... feathering the clutch is releasing the clutch smoothly and slowly, you definately want to do this with an AWD tranny

 

Changing your tranny and motor mounts to STi Group N mounts will help that nasty second gear lurch. Even feathering on stock mounts will cause a slight lurch, the STi mounts cure that almost completely. The stock tranny mount is pretty much hollow and it made to transmit less vibration through the frame. The group N STi mounts are completely solid(the group N wrx mounts help a little, but they aren't quite as rigid as the STi versions). Vibration is increased slightly but gear changes come on much better.

To smooth up shift feeling changing your gear oil to 75W90NS or Superlight Shockproof will smooth your shifting as well as protect your gears better.

The 2-1 shift in a rex is always deadly, changing the oil will help with the downshift, double clutching with rev matching will help a lot, but waiting until you're stopped to put it back into 1 is the only way to make it completely happy.

If you want your tranny to last, try to avoid dumping the clutch, and never ever force it into a gear, if it doesn't want to go don't force it. A short shifter will help you against forcing as you won't have as much force to exert because your leverage is a lot less, you'll still be able to tweak a shift fork if you he-man a shift, but it's a little harder to do.

I hope this helps you out.