Hi guys,
Seeing as though my knowledge of manual transmissions is near zero, can someone tell me if it is a bad idea to be shifting from 1st to 3rd. Still haven't changed my syncro mesh (saving up), and in the mean time this is my way around a faulty 2nd gear syncro mesh.
What negative effects can this have on my transmission?
Thanks
Mike

 

Shifting "out of order" so to speak presents no ill effects (your tranny doesn't have a clue that there is a specified order). A lot of instructors I have driven and ridden with will recommend a 5th to 3rd downshift as opposed to a 5th to 4th to 3rd. You would however want to avoid bogging the motor. Basically from my understanding (which might be no better than yours), the best way to save your syncros is to double clutch (or have the lay shaft speed equal the wheel speed). Assuming from your statement that you have a problem shifting into 2nd, you might want to practice a double clutch from 1st to 2nd (I find this one the more difficult than any other) and likewise from 3rd to 2nd when needed.

FWIW

 

Well you can help prevent your tranny from going further bad, by simply not downshifting (use your brakes, stick it in neutral, and stick it in the appropriate gear once you have found your desired speed).
Certain gears in certain trannies also like you to line up the gear to help. For example if you have gronchy shift problems, you stick it in another gear first, then put it in the gronchy gear, and it no longer gronches. So what you should have been doign before even wen the gear wasn't gronching, was sticking it in that other gear first, so that it would help line up the gears to help prevent wear on the synchros, but how were you to know that? Usually people just learn how to do it once they NEED to do it, when they really should have been doing that all along.
Downshifting in my opinion is not worth it, your brakes are a lot easier to change than a tranny, and learning to use your brakes only makes cornering easier and faster, heel and toe IMO is for cars that don't have very good brake setups
928 brakes are a suggestion
Formula 1 drivers don't downshift to brake, there is no time for that, they slam on the brakes with the clutch in and flick the buttons on the steering wheel as fast as they can to the approriate gear.

 

Skipping gears on an upshift is no problem as the worst that can happen is the motor will bog or stall. Be VERY careful skipping gears on a downshift. If you go from say 5 to 3 consider what 2 things may happen if your foot slipped off the clutch. First the engine would start turning at 10,000 rpm leaving oil and metal trailing behind you! The sudden gearing down and deceleration could cause a spin if you weren't going straight. Sometimes it is better to move the lever through the intermediate gears even if you don't actually let the clutch out just in case. . .

 

So downshifting from third to second will cause the syncro mesh to need changing? I always thought that if I am reving about 2500-3000rpm in third gear and I put the car in second, and lift the clutch slowly to slow down the car, that this does not affect the syncro, or other components (especially expensive one !).
I guess I need someone to explain to me how downshifting works!!
Does anyone think my driving method resulted in my 2nd gear syncro giving out on me?
If so, let me know, cause I think I'm gonna give up the downshifting forever!!
Thanks
Mike

 

http://www.g-speed.com/pbh/double-clutch.html

 

Thanks Adam,
Useful website

 

Yes, nice site, lots of good info.
Who wants to try shifting with no clutch

I like this line here:

" This
requires heel-and-toe to blip the throttle to rev-match the layshaft. The
only reason that this is the "classic" method is because they used the
engine braking in Second to help out their lousy brakes."

hehehe.

 

Used to do it all the time in my RX-7

 

The trannys are made differently. If you shift without the clutch then you are going to wear out the syncos. Trust me! i am in the middle of a rebuild. The "layshaft" will always spin at the same speed as the wheels. they are directly connected via the differential pumpkin. I could post some pictures if you want so you all can see what they look like. what do you want to see?

-andrew

87 turbo
2 - 83 N/A's

 

damn, too bad

is that for all porsche trannies? 924's, 944's?? 951's?

 

 

Sorry lars... been awhile since i have looked. The trannies all work the same on all cars. the 924's lack the fifth gear so the tranny does differ and there is only two pieces opposed to three... but all and all there are just to shafts the main in and the pinion shaft. on the pinion shaft, first and second gears are free spinning gears while third, forth, and fifth are press or spline fits. then on the main input shaft first and second are "built on" (or are part of the shaft and 3,4, and 5 are free spinning.

i hope you find this useful some how.

oh, on a side note the gears are always engaged, weather the "slide assembly" is is what makes the difference.

-andrew

87 turbo, soon to be driving again
2 - 83 N/A

 

Mike 944 - Letting your clutch out slowly to assist in slowing down your car is wearing your CLUTCH more than anything else. Clutch replacement is $1500, brake pad replacement is around $200 (and that's for good pads).

I, myself, try to match engine to tranny speed as best as possible by clutching, pressing on the gas, then letting the clutch out "swiftly". If you have the RPM's close, the car won't lurch at all, and you have very little wear on the synchros and clutch in the process. In high-stress driving situations, I just jam on the brake and pick the best gear for the road speed, then pop the clutch and go.

Greg

 

Thanks for the reply Greg...I think I am going to be getting rid of that habit, and learn to double clutch to save the syncros.
Thanks to everyone who replied