shifting....
10-08-2009, 10:56 PM
#1
On The Tree
Thread Starter
shifting.... couple things....
first off... lets say i race up to 70mph and then want to shift into 6 without hurting the syncro... i keep the clutch in and wait for the RPMs to lower to around 1500 and put it in 6th....? otherwise if i push 6th in prior to this it will feel like it doesnt want to go in... so that hurts the syncros if you try to push it in too early??
second of all.... my 3rd gear randomly pops out...?!?! right when i got the car it seemed to happen a decent amount but now that i've had the car for a while it doesnt seem to happen as much (i just work around it, and downshifting double clutching it goes in fine)
anythoughts?
first off... lets say i race up to 70mph and then want to shift into 6 without hurting the syncro... i keep the clutch in and wait for the RPMs to lower to around 1500 and put it in 6th....? otherwise if i push 6th in prior to this it will feel like it doesnt want to go in... so that hurts the syncros if you try to push it in too early??
second of all.... my 3rd gear randomly pops out...?!?! right when i got the car it seemed to happen a decent amount but now that i've had the car for a while it doesnt seem to happen as much (i just work around it, and downshifting double clutching it goes in fine)
anythoughts?
10-09-2009, 12:10 AM
#3
On The Tree
Thread Starter
ok well what is a tell tail sign you need new syncos.... because i've never actually grinded the gearbox... i'm wicked careful with it any downshift i do is double clutched or atleast rev matched...
10-09-2009, 07:20 AM
#4
part of why syncros exist is to keep you from having to double clutch. If you have to in order to get into gear, you're pretty much in need of a rebuild. Single gear issues also point to individual problems within. Also if you are going into 6th, you aren't racing any more at this point so don't try to speed shift it or power shift it, just let the revs get to where they should be for the speed you are at and go into gear.
Grinding is not necessarily the only sign to indicate syncro failure. Any thing outside of normal gear operation, such as popping out of gear or the need to double clutch for individual gears are big symptoms in itself.
Grinding is not necessarily the only sign to indicate syncro failure. Any thing outside of normal gear operation, such as popping out of gear or the need to double clutch for individual gears are big symptoms in itself.
10-09-2009, 10:03 AM
#6
On The Tree
Thread Starter
~60k miles...
the only gear to ever give me trouble is 3rd... all others are fine
i just chose to downshift with double clutching for the fact i dont want to harm the syncros.. and it seems to be a smoother shift at the same time...
i have read if you go from say 6th to 3rd (on a highway cruisin around 50) you have to double clutch or else the syncros just cannot take it to get into 3rd from jumping 3 gears? when i double clutch it goes in seamlessly
and as far as normal 1 gear downshifts i atleast rev match usually... 6th to 5th usually doesnt need it because you're slowing down and the gears arent that different
am i right?
and what are keys
the only gear to ever give me trouble is 3rd... all others are fine
i just chose to downshift with double clutching for the fact i dont want to harm the syncros.. and it seems to be a smoother shift at the same time...
i have read if you go from say 6th to 3rd (on a highway cruisin around 50) you have to double clutch or else the syncros just cannot take it to get into 3rd from jumping 3 gears? when i double clutch it goes in seamlessly
and as far as normal 1 gear downshifts i atleast rev match usually... 6th to 5th usually doesnt need it because you're slowing down and the gears arent that different
am i right?
and what are keys
10-09-2009, 10:40 AM
#7
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mine does that on occasion, sometimes when i try to powershift 3rd, it just won't let me in and it'll pop out of 4th just cruising normally sometimes. i'd say synchros. time to send it to tick!
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10-09-2009, 11:31 AM
#8
normal transmissions don't pop out of gear
normal transmissions with working hydraulics don't block you out of gear
if you suffer from these symptoms, don't try and convince the people who don't have these problems that its normal to double clutch as a solution.
So realize that if you don't have to do it for the other gears, then you probably do have a problem with either the keys or syncros at the most and if you are going to to tear it down, you might as well upgrade/repair all of them at the same time. All it takes is a good rev match to save your transmission, not choose a gear, probably most people can select whatever gear they want at speed without having to double clutch it. (save first gear unless slowing to a crawl)
normal transmissions with working hydraulics don't block you out of gear
if you suffer from these symptoms, don't try and convince the people who don't have these problems that its normal to double clutch as a solution.
So realize that if you don't have to do it for the other gears, then you probably do have a problem with either the keys or syncros at the most and if you are going to to tear it down, you might as well upgrade/repair all of them at the same time. All it takes is a good rev match to save your transmission, not choose a gear, probably most people can select whatever gear they want at speed without having to double clutch it. (save first gear unless slowing to a crawl)
10-10-2009, 07:28 PM
#10
On The Tree
Thread Starter
so you're saying to go directly from 6th to 3rd @ 50 mph... you dont have to rev match or double clutch at all....?
i'm not experienced with transmissions but logically a shaft spinning for crusing at 50 mph going to spinning possibly 3 or 4 times as much (to 3rd gear) seems like quite a lot of force on the syncro to take it all... as far as i knew syncros were built to accomedate normal 1 gear at a time shifts up or down
i'm not experienced with transmissions but logically a shaft spinning for crusing at 50 mph going to spinning possibly 3 or 4 times as much (to 3rd gear) seems like quite a lot of force on the syncro to take it all... as far as i knew syncros were built to accomedate normal 1 gear at a time shifts up or down
10-10-2009, 07:39 PM
#11
rev match yes, double clutch NO
The rev match is really meant to save your engine and clutch combo. Think of it this way, the transmission once power is removed will synchronize itself accordingly. Thus you can choose whatever gear you want. The engine on the other hand is NOT spinning at the same speed as the input shaft though. Ever hear of the dreaded 5-2 shift? Why do you think its possible to select 2nd gear? That's a synchronized transmission for you. When the clutch is released though the engine is spun up by the momentum of the input shaft via the clutch. Think about it, you have 28lb flywheel, a 20 lb pressure plate and the engine which is not at the same speed. If the clutch grabs hard, that's a LOT of energy transfer going the other way. That's why you rev match. The gear selection happens long before that.
The rev match is really meant to save your engine and clutch combo. Think of it this way, the transmission once power is removed will synchronize itself accordingly. Thus you can choose whatever gear you want. The engine on the other hand is NOT spinning at the same speed as the input shaft though. Ever hear of the dreaded 5-2 shift? Why do you think its possible to select 2nd gear? That's a synchronized transmission for you. When the clutch is released though the engine is spun up by the momentum of the input shaft via the clutch. Think about it, you have 28lb flywheel, a 20 lb pressure plate and the engine which is not at the same speed. If the clutch grabs hard, that's a LOT of energy transfer going the other way. That's why you rev match. The gear selection happens long before that.
Last edited by SladeX; 10-10-2009 at 07:45 PM.
10-11-2009, 01:44 PM
#12
On The Tree
Thread Starter
yeah the engine/clutch thing you said makes sense.... going 5th to 2nd with only rev matching kind of scares me lol... i can do it no problem double clutching and in a way its more forgiving...? the whole point of double clutching is it aligns the input shaft, clutch, engine, and output shaft by spinning the input shaft... or thats how i understand it... idk i could have sworn i read that doing anything more than 1 gear downshifts is harmful to the syncros becaus ethey're only designed for 1 gear downshifts...
idk maybe its a sense of security i have.
thanks for the information tho
idk maybe its a sense of security i have.
thanks for the information tho
10-11-2009, 02:01 PM
#13
as stated, there is no need to double clutch.
"Double clutching" was a term made recently popular by those fast & furious movies. In reality, a double clutch slows down your shifting significantly. What makes you think your left foot is faster than an internal piece of technology? What tells you it's safer?
A rev match is a necessity for a safe downshift just as is letting off the gas is a necessity for a smooth upshift. The difference in speed of the engine rpm versus the internal transmission rpm is what kills transmissions in the long run as you are "shocking" the system either engine to drivetrain and vice versa if they are not at the same speed when you reconnect the 2 sections via engaging the clutch.
Your goal should be a driver fix. Sync yourself to your car, not apply some old shifting technique that existed before syncronized transmissions. It's pointless unless your syncros are damaged and not working anymore. Then that's when you limp the car home and fix the transmission, not continue to perfect an old technique on a modern transmission.
"Double clutching" was a term made recently popular by those fast & furious movies. In reality, a double clutch slows down your shifting significantly. What makes you think your left foot is faster than an internal piece of technology? What tells you it's safer?
A rev match is a necessity for a safe downshift just as is letting off the gas is a necessity for a smooth upshift. The difference in speed of the engine rpm versus the internal transmission rpm is what kills transmissions in the long run as you are "shocking" the system either engine to drivetrain and vice versa if they are not at the same speed when you reconnect the 2 sections via engaging the clutch.
Your goal should be a driver fix. Sync yourself to your car, not apply some old shifting technique that existed before syncronized transmissions. It's pointless unless your syncros are damaged and not working anymore. Then that's when you limp the car home and fix the transmission, not continue to perfect an old technique on a modern transmission.
10-11-2009, 05:38 PM
#14
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You can downshift into ANY gear you want, coming from ANY gear you are in. Period. If you can't...problem.
Now, that is being logical, as I would hope that one would think that they can not safely downshift from say 100MPH and 6th gear down into 1st gear. Was hoping that everyone understood that.
But, normal speeds, like say 60 or 70 MPH, and you are in 6th gear, then YES, you can downshift into 3rd if you want.
If pops out of gear like you say, probaly keys, or pads...but could also be fork or shifter rail. Either way, you DO have a tranny issue, and needs to be opened up to find the problem.
If you can't handle teh rebuild yourself, you can always send it to my shop, as we do T56 rebuilds, stock AND performance rebuilds.
Thanks
Now, that is being logical, as I would hope that one would think that they can not safely downshift from say 100MPH and 6th gear down into 1st gear. Was hoping that everyone understood that.
But, normal speeds, like say 60 or 70 MPH, and you are in 6th gear, then YES, you can downshift into 3rd if you want.
If pops out of gear like you say, probaly keys, or pads...but could also be fork or shifter rail. Either way, you DO have a tranny issue, and needs to be opened up to find the problem.
If you can't handle teh rebuild yourself, you can always send it to my shop, as we do T56 rebuilds, stock AND performance rebuilds.
Thanks
10-12-2009, 12:35 AM
#15
On The Tree
Thread Starter
well yeah i understsand where you guys are coming from... today i messed around more with rev matching rather than "double clutching" and i have to practice... 3rd didnt give me any trouble today so idk.
it may have been when i was just new with the car? one thing i noticed tho if i'm going around a corner it happens more often out of the times it does occur..?
it may have been when i was just new with the car? one thing i noticed tho if i'm going around a corner it happens more often out of the times it does occur..?