Manual Transmission T56 | T5 | MN12 | Clutches | Hydraulics | Shifters

Shifting problem persists; unable to shift quickly.. HELP!!

Thread Tools
 
Search this Thread
 
Old Oct 27, 2008 | 09:00 AM
  #1  
Aetos's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Exclamation Shifting problem persists; unable to shift quickly.. HELP!!

Problem: Shifting quickly is IMPOSSIBLE in my car. If you press the clutch in and try to shift into any gear you either get a "block" for about a split second before it goes into gear. If you don't get the "block" you hear a high pitch/clunk sound coming from underneath the shifter or somewhere there. They both let you engage the gears, but its not smooth or safe sounding.

Here is the catch though, it only happens during the first time you shift into gear with the clutch down... to put it easier:

1) press clutch
2) Engage into gear quickly and get the block
3) DO NOT RELEASE CLUTCH
4) Go into any other gear and its completely smooth, no matter how many times you shift. It will be like a knife slicing through butter going into gears.
5) release clutch
6) press clutch down again and process repeats

If you shift slowly and let the gear "suck" the shifter in and just ease it into gear (2-3 seconds), the gear will engage with no apparent sound, but the block is still there, but after a bit the shifter will just slide into the gear.

Attempts to fix problem:
1) New transmission fluid
2) New GM master
3) Drill mod
4) New Hydraulic fluid

Edit: I have also done the clutch slipping tests.

Revving to 5-6k at a stop with clutch down does not move my car at all.
Hitting the throttle at around 20mph in 4th has a steady increase of rpm/mph, not a wide variation between them.

Last edited by Aetos; Oct 27, 2008 at 10:08 AM.
Reply
Old Oct 27, 2008 | 04:33 PM
  #2  
Aetos's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Default

19 views and no idea?
Is everyone as stumped as I am on this? lol
Reply
Old Oct 27, 2008 | 07:21 PM
  #3  
Vicinity's Avatar
TECH Fanatic
iTrader: (7)
 
Joined: Dec 2007
Posts: 1,752
Likes: 0
From: FL
Default

Mines done that since I got it, figured it was normal.
Reply
Old Oct 27, 2008 | 07:33 PM
  #4  
Aetos's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Default

Originally Posted by Vicinity
Mines done that since I got it, figured it was normal.
Can that really be normal? I can't shift quick enough to make my tires chirp or squeal with the current problem. I can try, but I never have because of the grinding noise upon quick shifting. I'm worried that I'm damaging something very expensive and hard to change.
Reply
Old Oct 27, 2008 | 08:22 PM
  #5  
Vicinity's Avatar
TECH Fanatic
iTrader: (7)
 
Joined: Dec 2007
Posts: 1,752
Likes: 0
From: FL
Default

Do you have enough fluid in there? I know when mines low I cannot chirp, but I can normally.
Reply
Old Oct 27, 2008 | 08:38 PM
  #6  
Aetos's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Default

Originally Posted by Vicinity
Do you have enough fluid in there? I know when mines low I cannot chirp, but I can normally.
Yes, It has the 4 quarts, it was still happening before the tranny fluid change also, so I'm pretty sure its not the fluid.
Reply
Old Oct 27, 2008 | 08:48 PM
  #7  
camarosam22's Avatar
Launching!
 
Joined: Apr 2008
Posts: 214
Likes: 0
From: Glendale, Ca
Default

It could be just the shifter, the stock ones are known to not be very smooth. My last camaro had that issue but never figured out what it was. My camaro now shifts nice, but still has a grab feeling.
Reply
Old Oct 27, 2008 | 09:02 PM
  #8  
Aetos's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Default

Originally Posted by camarosam22
It could be just the shifter, the stock ones are known to not be very smooth. My last camaro had that issue but never figured out what it was. My camaro now shifts nice, but still has a grab feeling.
Forgot to mention it, I have a pro 5.0, but how could a shifter cause GRINDING problems?
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Oct 27, 2008 | 09:26 PM
  #9  
SladeX's Avatar
TECH Addict
15 Year Member
 
Joined: Nov 2005
Posts: 2,379
Likes: 2
Default

Sounds like hydraulics, if there is the smallest amount of air stuck in the system, it will act like that on the quick shift, but if delayed will eventually allow normal shifting like butter.

Invest in a mityvac and see how it is after using that on the system. Other symptoms (which you may be afraid to encounter) would also be clutch sticking at high rpm, or a quick shift at WOT will act like a wall is there.
Reply
Old Oct 27, 2008 | 09:48 PM
  #10  
Aetos's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Default

Originally Posted by SladeX
Sounds like hydraulics, if there is the smallest amount of air stuck in the system, it will act like that on the quick shift, but if delayed will eventually allow normal shifting like butter.

Invest in a mityvac and see how it is after using that on the system. Other symptoms (which you may be afraid to encounter) would also be clutch sticking at high rpm, or a quick shift at WOT will act like a wall is there.
Don't think there is any air in the systems; just installed a brand new master and bleeded the **** out of it after the install, so I highly doubt theres any air.
Reply
Old Oct 28, 2008 | 10:03 AM
  #11  
06black6spd's Avatar
12 Second Club
 
Joined: Sep 2008
Posts: 185
Likes: 0
From: Manchvegas, NH
Default

Clutch fluid heating up too much? Is it usually durring high RPM's?
Reply
Old Oct 28, 2008 | 10:13 AM
  #12  
Aetos's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Default

Originally Posted by 06black6spd
Clutch fluid heating up too much? Is it usually durring high RPM's?
As stated in the original post it always happens, even while sitting still without driving at all.
Reply
Old Oct 28, 2008 | 10:42 AM
  #13  
Aetos's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Default

Originally Posted by 06black6spd
Clutch fluid heating up too much? Is it usually durring high RPM's?
It occurs even during idle, without having driven the car beforehand.
Reply
Old Oct 28, 2008 | 10:47 AM
  #14  
SladeX's Avatar
TECH Addict
15 Year Member
 
Joined: Nov 2005
Posts: 2,379
Likes: 2
Default

Once air got introduced into my slave due to an accidental pump while bleeding. I bled the **** out of it after that and supposedly all was fine. Fast forward a few months and during a WOT run in 3rd I found it sticking. I rebled, got clean fluid out, but the "air" was still trapped. I found this out while doing 4th gear pulls on a dyno when tuning my car.

Bled again, it was still sticking. Got fed up, bought a mityvac and pulled a lot of "trapped" air within the system. Significant amount. Took it for a long drive, then did a few WOT pulls to the top of 5th. Shifted like butter at redline.

I've bench bled the master and left it hanging in the garage overnight, sure enough thanks to the angle I left the system at, air worked its way up the system back into the reservoir. Once air gets in, it is a PAIN to get out. On top of that, it will disperse itself into the fluid and lower the boiling point further creating and trapping gasses from the degraded fluid at each WOT run.

I'm saying if you've exhausted all avenues with hardware, bleeding for air etc, then last point of failure is the clutch itself.

From what it sounds like either a) hole in system, air is getting in, or b) line is touching header and boiling fluid.
Reply
Old Oct 28, 2008 | 05:13 PM
  #15  
Aetos's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Default

Update: Took the car to a mechanic I know so he can drive it around a bit and try to tell me the problem. He came to the conclusion thats its probably one of three things; air in the slave(yay SladeX!!), the slave itself may be going bad, or the pressure plate may be bad. He said the sound that emits during shifting is the clutch.

I just ordered a mity vac to try and bleed it out. If that doesn't work, I have a brand new slave sitting in my hatch(reluctant to drop the tranny). If that doesn't work either, I guess Im gonna be ordering the LS7 clutch.
Reply
Old Oct 29, 2008 | 08:07 PM
  #16  
davidz28man's Avatar
Teching In
iTrader: (11)
 
Joined: Jul 2008
Posts: 41
Likes: 0
From: goldsboro
Default t56

sounds to me like you either have worn sencros or dameged key ways or even blocker rings . i dont think you have air in your system. only because i had almost the same problem and i bled my for hours and the same problem continued. i took mine apart and replaced the blocker rings , sencros, key ways. and had know more problems. note it is good practice if you take the tranny apart and rebuild it to give it new hydraulics....
Reply
Old Oct 29, 2008 | 08:52 PM
  #17  
Aetos's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Default

Originally Posted by davidz28man
sounds to me like you either have worn sencros or dameged key ways or even blocker rings . i dont think you have air in your system. only because i had almost the same problem and i bled my for hours and the same problem continued. i took mine apart and replaced the blocker rings , sencros, key ways. and had know more problems. note it is good practice if you take the tranny apart and rebuild it to give it new hydraulics....



I have 47k miles and it happens in all gears, at all speeds, even at idle... how would this be something internal unless I got like the most messed up tranny in an fbody. The mechanic himself told me its either the slave or a clutch.
Reply
Old Oct 29, 2008 | 09:46 PM
  #18  
SladeX's Avatar
TECH Addict
15 Year Member
 
Joined: Nov 2005
Posts: 2,379
Likes: 2
Default

usually , 1 gear = specific internal problem, 2 gears (related), ie 1-2 or 3-4 or 5-6 still a specific problem, but all gears usually point to clutch issues, in particular the hydraulics
Reply
Old Oct 30, 2008 | 09:09 AM
  #19  
Aetos's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Default

Originally Posted by SladeX
usually , 1 gear = specific internal problem, 2 gears (related), ie 1-2 or 3-4 or 5-6 still a specific problem, but all gears usually point to clutch issues, in particular the hydraulics
That's what I believed so I rationalized around that belief, you just made that belief stronger now, thanks!
Reply
Old Oct 30, 2008 | 09:11 AM
  #20  
06black6spd's Avatar
12 Second Club
 
Joined: Sep 2008
Posts: 185
Likes: 0
From: Manchvegas, NH
Default

Intiresting, Ive been following this thread, would love to know the end all issue
Reply



All times are GMT -5. The time now is 10:32 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE