bengali548

hey guys

its not really a problem this was just on my mind but k lets say your going 120 in fifth and you wanted to drop into first why do you hear a grinding sound

like once the tranny is disconnected the layshaft slows down (i think) and your driveshaft is spinning at 120 so shouldnt i be able to pop into first release clutch and just have my engine red line i thought the syncros would speed up first gear so it could catch?

if any of this sounds weird sorry lol i had a curious george moment and wikid how stuff worked so ya

spike

Your a retard if you try to go into 1st at 120, it's not geared for the speed.

rick10

why would you want to even try to pop it into first gear if you are going 120 .... you may as well try to see what happens putting in reverse at a 120....

From my experience , i was teaching my wife how to drive manual (big mistake) and she was going 60 k and she was trying to put it in 3 gear but by mistake she put it in first and let me tell you it wasnt a pleasent sound , it almost felt like you hit something ... so yea dont play around with that unless you want to get into an accident and blow your tranny

chris_v2

Seriously......

bengali548

lol no no i know its retarded to do that but im asking why it wont go in so i can get a better understanding of how trannys work lol

basically WHATS STOPPING IT FROM GOING INTO FIRST GEAR

D.T.P

Yeah I was wondering same thing before. Lol wow we sound stupid, but while clutch is engaged shouldn't I be able to put it into first. I wouldn't let off the clutch cuz well obviously that wouldn't be good haha but it just won't go into first even with clutch engaged.
I'm just curious just for informational purposes.

MPR

In order to be in 1st gear with the wheels going at 120kph the engine rpm would have to be rediculously high (if I knew the ratio I'd calculate it), but it's damn high, like your engine would blow instantly.

The syncro's can't match the rpm so it simply won't go into gear.

I'll explain more in-depth later...gotta go do some work. lol

D.T.P

But when you engage the clutch pedal, doesn't the clutch disk move away from the flywheel causing engine to not spin the transmission? If so why would it you need to be in high rpm?

MPR

I'll explain it all later, just workin right now.

Stay tuned....lol

Yong_STballaEM2

granny shifting not double clutching like you should

bengali548

ya thats exactly what i was wondering about

D.T.P

lol

jamie1985

Its the synchros preventing the gear to engage due to the difference in rotating speeds of the input and output shafts. The output shaft is simply spinning too fast to mesh the gears properly with the input shaft of the 1st gear, hence the grinding.

Manual transmission - Wikipedia, the free encyclopedia read section on synchronized transmissions

How Manual Transmissions Work more info

and finally... HowStuffWorks "How Manual Transmissions Work"

D.T.P

^^makes sense. thx

jamie1985

no problem

bengali548

Ic so fifth to fourth is easier than fifthtp to first because the size of the 1st gear is too small and therefore spinning to fast?

jamie1985

that is correct!

bengali548

Granny shifting is so much less work lol

MPR

jamie1985 beat beat me to it...

The gears simply can't mesh because of the ratio and the difference in input and output shaft speeds.

jamie1985