[gotnospice]

Has anyone else noticed the gears grinding when you slow down fast, come to a stop and quickly put it in first to start again. It makes a horrible grinding noise. At first I thought I just messed up and didn't have the clutch all the way down. But then it happened again and it was def all the way down. Is it something to do with the RPMs or speed and how 1st gets locked out at certian speeds? Anyone else notice what I'm talking about?

 

[saitech]

Hmm...you said you are slowing down fast. Is that maybe your abs kickin in?

 

[gotnospice]

Naw, I used to live in Connecticut and had a van with ABS, after many, many snowy parking lots I know what ABS sound like, hahah. It's def coming from the transmission, I don't like the noise so I don't want to try to reproduce it again, but i'll pay more attention if it happens again.

 

[redms3gt]

R U rev matching when you downshift or just jamming it in first at 25mph. The syncros will only do so much. They do work good once warm though.

 

[gotnospice]

I try to rev match, but the thing is I don't even let the clutch out. The clutch is all the way in and I hear the noise when going into first. The syncros shouldn't even be activated yet.

 

[Chipotle]

I want to say this happens to me as well. I also want to say its happened on another vehicle as well. I'll keep a feel out.

 

[Trubopower]

You shouldn't really need to jam it into first if you are slowing down and go right again, if theres any foward motion 2nd is a better choice. Most tranny's dont like to be put into first after takeoff

 

[dmention7]

[quote author=gotnospice link=topic=69924.msg1217284#msg1217284 date=1171921905]
I try to rev match, but the thing is I don't even let the clutch out. The clutch is all the way in and I hear the noise when going into first. The syncros shouldn't even be activated yet.
[/quote]

The synchros are what allow the gears to mesh properly when you shift--nothin to do with the clutch. And it kind of does sound like that might be part of the problem.

You could try double-clutching before you put it back into first--put the car in neutral, let the clutch out for a split second, then press it back in and immediately shift into gear.

 

[gotnospice]

I don't really get double clutching, what does that do and why does it help with anything. I've read all about it, tried it but don't use it. Do you only double clutch down shifting or both up and down? Putting the clutch all the way down completely is the same as neutral, the gears are out of the equation. So can't you just leave the clutch in a second longer rather then put it in twice?

 

[john_in_the_lbc]

[quote author=gotnospice link=topic=69924.msg1216942#msg1216942 date=1171913924]
Has anyone else noticed the gears grinding when you slow down fast, come to a stop and quickly put it in first to start again. It makes a horrible grinding noise. At first I thought I just messed up and didn't have the clutch all the way down. But then it happened again and it was def all the way down. Is it something to do with the RPMs or speed and how 1st gets locked out at certian speeds? Anyone else notice what I'm talking about?
[/quote]

are you slowing down the engine with the car in gear or are you "flywheeling", meaning pressing in the clutch at high revs and coasting to a stop in neutral with the clutch in, as though you're trying to save as much gas as possible?

 

[redms3gt]

In gear with clutch in is still in gear. just not connected to the wheels. It has the same effect but not the same. If the revs dont match the speed for the gear the syncos have to work to make the speeds of the gears the same so they can sync. The resisance you feel when down shifting is the syncos trying to equalize the speeds. If you force it before the acheive the same speed it grinds. If the speed are the same as with rev matching the gears just fall into place and its an easy shift. Syncos or not. If the speeds are exact the clutch will not even have to be used.

 

[gotnospice]

[quote author=John_in_the_LBC link=topic=69924.msg1217396#msg1217396 date=1171924391]
are you slowing down the engine with the car in gear or are you "flywheeling", meaning pressing in the clutch at high revs and coasting to a stop in neutral with the clutch in, as though you're trying to save as much gas as possible?
[/quote]

No I down shift every gear down to 3rd, and then put it in neutral.

 

[dmention7]

[quote author=gotnospice link=topic=69924.msg1217373#msg1217373 date=1171923917]
I don't really get double clutching, what does that do and why does it help with anything. I've read all about it, tried it but don't use it. Do you only double clutch down shifting or both up and down? Putting the clutch all the way down completely is the same as neutral, the gears are out of the equation. So can't you just leave the clutch in a second longer rather then put it in twice?
[/quote]

Putting the clutch down is not the same as neutral. If you are in gear with the clutch pressed in, then the gears in the transmission are turning with the wheels, but the transmission's input shaft is disconnected from the engine. If you put the car in neutral, and let the clutch out, then the input shaft to the transmission is connected to the engine, but the gears are not engaged to the wheels. There are two separate points of mechanical engagement in the drivetrain--one is controlled by the clutch pedal, the other is controlled by the shift lever.

When you try to put the car into 1st gear while still rolling, what happens is that the synchros are working hard to match the speed of the gears in the transmission to the speed of the wheels (which can be a lot of work, since 1st gear is so low). The reason you get grinding is just what redms3gt said: you're not giving the synchros time to match all of the moving parts to the same speed. When you double clutch, you let out the clutch with the car in neutral and give the gas a tap. This connects the engine to the gearbox and gets the gears spinning. Then you shift into gear quickly, and the synchros have a much easier time of meshing the gears together. Before the days of synchros, you pretty much had to do this with every downshift, otherwise the result would be exactly what you're describing.

 

[gotnospice]

[quote author=dmention7 link=topic=69924.msg1217465#msg1217465 date=1171927424]
...Before the days of synchros, you pretty much had to do this with every downshift, otherwise the result would be exactly what you're describing.
[/quote]

So double clutching is only used during down shifts or both? Which is more important? Thanks for all the clarification!

 

[dmention7]

[quote author=gotnospice link=topic=69924.msg1217474#msg1217474 date=1171927666]
[quote author=dmention7 link=topic=69924.msg1217465#msg1217465 date=1171927424]
...Before the days of synchros, you pretty much had to do this with every downshift, otherwise the result would be exactly what you're describing.
[/quote]

So double clutching is only used during down shifts or both? Which is more important? Thanks for all the clarification!
[/quote]

Mainly for downshifts since you need to get the gears to speed up to match the lower gearing. When you upshift, the gears naturally slow down when you let out the clutch, so you could probably shift "normally" then--I've never driven a non-synchro'd car, so I couldn't say for sure.

 

[mattleegee]

Time to come to a stop or close to a stop before shifting back into first

There are parts moving under there still!!

 

[gotnospice]

I usually hit the gas while I have the clutch in to get the RPMs up before letting out the clutch, this won't work too? I should let the clutch out, and back in instead?

 

[betelgeuse]

I agree with Matt, you really should try to avoid shifting to first unless you're coasting very slowly (like 5mph or so) or at a complete stop (recommended). Most would say never shift to 1st unless you're at a complete stop.

Normally, when coasting, you can slip the clutch a little to get a good start in 2nd without having to shift to first. Also you can rev match your downshifts without having to doubleclutch. It takes a little practice but it can be done in one single motion. You have to blip the gas as soon as the clutch disengages then complete the shift quickly matching the revs as they fall. With enough practice, you'll do it without thinking and everything will be smooth.

 

[solipsism]

Ive had a repeated issue (once a week or so) where after having stopped I cant shift into first. I have to wiggle the stick between neutral and 1st a couple times before it goes in, then its fine. I think it may have something to do with the reverse gear.

 

[brecker]

slide it into 2nd, then into 1st. An "OLD" manual trick.