M6 Need Help.... - Pontiac GTO Forum
User Tag List

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 14 (permalink) Old 03-03-2006, 11:05 PM Thread Starter
 
Dragon 32's Avatar
 
Join Date: Jan 2006
Posts: 254
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
M6 Need Help....

I was driving along in my GTO, went to shift into third and it would not shift, then I smelled something burning. I pulled over at a store and a guy said it smelled like my clutch burning. After sitting for 10 minutes the car shifted fine. Is this a problem that needs to be fixed ???? What is it if anyone know's ???
Dragon 32 is offline  
Sponsored Links
Advertisement
 
post #2 of 14 (permalink) Old 03-03-2006, 11:21 PM
 
QSGTO's Avatar
 
Join Date: Nov 2005
Location: Houston Texas
Posts: 178
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Dragon 32
I was driving along in my GTO, went to shift into third and it would not shift, then I smelled something burning. I pulled over at a store and a guy said it smelled like my clutch burning. After sitting for 10 minutes the car shifted fine. Is this a problem that needs to be fixed ???? What is it if anyone know's ???
I have had this happen several times under hard shifting conditions minus the smell. It sounds like you were driving hard. If this happens again, shift into fourth then back to third while holding the clutch pedal down then engage in third. If this works, you might have a misaligned synchronizer. If you are in warranty, bring it to his attention at the dealer. Don't say you were racing it or anything. If they ask, say you don't abuse it, but you do drive it like it is meant to be driven. It isn't a grocery getter.
QSGTO is offline  
post #3 of 14 (permalink) Old 03-04-2006, 07:20 PM
 
Join Date: Nov 2005
Posts: 700
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Do we have synchros in this transmission? I was under the impression that we didn't. I may be wrong though. I am quite forgetful and anything that isn't written down or tattooed on my body is typically forgotten quickly. hehe
I smell burned clutch (and brakes, and tires, and oil, etc) often after some hard driving, I haven't ever had it fail to shift though. I bet they won't be able to reproduce it at the dealership, which will really suck.
Good Luck though, and please post back when you find out what the problem is/was.
baron_iv is offline  
 
post #4 of 14 (permalink) Old 03-04-2006, 10:48 PM
 
QSGTO's Avatar
 
Join Date: Nov 2005
Location: Houston Texas
Posts: 178
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by baron_iv
Do we have synchros in this transmission? I was under the impression that we didn't. I may be wrong though. I am quite forgetful and anything that isn't written down or tattooed on my body is typically forgotten quickly. hehe
I smell burned clutch (and brakes, and tires, and oil, etc) often after some hard driving, I haven't ever had it fail to shift though. I bet they won't be able to reproduce it at the dealership, which will really suck.
Good Luck though, and please post back when you find out what the problem is/was.
Most transmissions don't have a reverse synchro, but the M6 has a synchro for every gear. To reproduce this problem, they will have to speed shift.
QSGTO is offline  
post #5 of 14 (permalink) Old 03-05-2006, 07:59 AM
 
Join Date: Dec 2004
Posts: 364
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Dragon 32
I was driving along in my GTO, went to shift into third and it would not shift, then I smelled something burning. I pulled over at a store and a guy said it smelled like my clutch burning. After sitting for 10 minutes the car shifted fine. Is this a problem that needs to be fixed ???? What is it if anyone know's ???
It could be a synchro problem, but that should cause any smell. The smell could be from your clutch plates rubbing together, but... really hot brakes can smell similarly to the clutch plates. So, if you were running down a back road somewhere and got the brakes really hot, the smell and the shifting problem might not be related.

If you are using your clutch properly on the road, it really shouldn't be under that much stress. I had my clutch plates checked after two seasons of racing and they looked practically brand new. But, I don't ever ride my clutch and I match revs on downshifts (toe/heel downshifting) so there isn't very much slippage of my clutch plates. The heat gets into the clutch plates if there is slippage. If they are engaged, they are just two plates spinning in unison. Slippage could be the result of improper driving (riding the clutch, not matching revs and doing lots of downshifts, hard launches from a stop, etc) or it could be a material problem with the clutch where the clutch plates are not pressing together hard enough to prevent slippage under the motor's full torque. If you got the clutch plates hot from slippage, then let them cool 10 minutes, that might explain why it worked fine at that point. But it doesn't explain why they slipped in the first place.
Subdriver is offline  
post #6 of 14 (permalink) Old 03-05-2006, 11:57 AM
 
Join Date: Nov 2005
Posts: 700
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
My feet are too dang big to heel-toe shift, so I'm pretty much outta luck. I didn't really take that into account when I bought the car though, so I guess there's not much I can do about that. I had become a double-clutching master after driving a 59 chevy truck which had been converted into a quarter mile screamer when I bought it...unfortunately, that's not required anymore either. That's good though, it was a pain in the butt to learn to double clutch at first. Heel-toe shifting was so much easier in the old truck though, there was enough room down there in the floor for a full size human to work the pedals if you wanted. hehe
Got any tips for people with big feet who need to heel-toe shift??
baron_iv is offline  
post #7 of 14 (permalink) Old 03-31-2006, 03:04 AM
 
QSGTO's Avatar
 
Join Date: Nov 2005
Location: Houston Texas
Posts: 178
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
They did have several problems with all the flywheel bolt not being evenly torqued. This can make the clutch not make full pressure contact on several places on the flywheel. If that happens, the clutch can smoke because there is not enough pressure on it.
QSGTO is offline  
post #8 of 14 (permalink) Old 03-31-2006, 05:59 AM
 
s2gordon's Avatar
 
Join Date: Dec 2005
Location: Orlando
Posts: 182
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'm a Noob... what exactly is "Heel Toe" shifting?
s2gordon is offline  
post #9 of 14 (permalink) Old 03-31-2006, 11:28 AM
 
Join Date: Nov 2005
Posts: 95
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Dragon 32
I was driving along in my GTO, went to shift into third and it would not shift, then I smelled something burning. I pulled over at a store and a guy said it smelled like my clutch burning. After sitting for 10 minutes the car shifted fine. Is this a problem that needs to be fixed ???? What is it if anyone know's ???
Since you have the clutch smell and you could not go into gear, I would have to believe when you stepped on the clutch pedal, it did not fully release the clutch. So, either you got the clutch fluid too hot where the clutch actuator couldn't move the clutch enough (i.e. your foot riding the clutch all the time) or there is air in the clutch fluid.
edysinger is offline  
post #10 of 14 (permalink) Old 03-31-2006, 08:27 PM
 
Mad_Dan_Eccles's Avatar
 
Join Date: Mar 2006
Posts: 47
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Heel and Toe

Quote:
Originally Posted by s2gordon
I'm a Noob... what exactly is "Heel Toe" shifting?
If you shift gears on a bog standard family car you'll prbably never need to know. However if you want to make life a bit gentler on the drivetrain when you're driving with a bit of enthusiasm or on the track it's a really handy way to get truly smooth shifts and reduce the strain on the mechanicals

When you shift gears in a modern transmission there are synchonisers built into the gearbox which adjust the speed of the shafts to match the ratio of the gear you are selecting.

However as you take your foot off the throttle and depress the clutch the engine revs drop and the engine speed is no longer synchronised with road speed, so the downshift is a little bit clumsier than it needs to be. The trick is to blip the throttle as you shift down which is awkward because your right foot is planted on the brake pedal as you head towards the bend.

So what you need to do is use your right foot for both brake and gas pedal at the same time - "heel and toe".

In the GTO I actually find it necessary to use the heel on the brake and my toe on the gas pedal - this was the old technique when cars were more basic and pedal tended to be bigger and need more effort.

In other cars like Alfas where the pedals are close together and about the same height it was easiest to use the inside of my foot on the brake and then roll my knee and ankle so the outside of my foot briefly touches the gas pedal to bring up the revs. You'll need to figure what works for you depending on the geometry of the pedals, the flexibilty of your knees and ankles and the size of your feet

In order
1 Right foot on brake - heel or whatever part will let you press the gas pedal
2 Clutch in and dab the throttle with the other part of your right foot until the revs are a just little above what you will need for the new gear while keeping the braking effort the same - a little above because the revs will drop while ou complete the shift
3 Shift into the new gear
4 Clutch out and away you go...

Number 2 is the part that needs practice. You'll find that your foot will move on the brake which means your braking affort will tend to change as you dab the gas pedal. After a while it will come naturally but in the meantime practice where there's no danger if you get it wrong and, if you're sensitive, do it where no one is looking at you

Now for the absolute smoothest changes you can refine the technique by double de-clutching as you shift. It's not necessary on a modern car with good synchro, but it's a real feel good moment when you do it right for the first time
1 Start braking
2 Clutch in
3 Shift into neutral
4 Clutch out
5 Dab the gas pedal while still leaving your foot on the brake to match the revs at the input shaft to the output revs for the gear you are shifting into
6 Clutch in
7 Shift into new gear
8 Clutch out.. and away you go again

(Admittedly I didn't learn to do this in a performance car but on a very old 88 inch wheelbase Land Rover which had synchro only on 3 and 4 and even then it was a bit hit and miss)

The old racing shift relied entirely on the drivers ability to match revs to gear and speed and was done without the clutch. Mostly it was done on the upshift since the down shift really needs a monentary clutch slip to avoid expensive noises unless you are very, very good and very, very consistent in your ability to match revs precisely to road speed. If you're not spot on the shock on the drivetrain or synchronisers can be more than metal can bear
Mad_Dan_Eccles is offline  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 2004-2006 GTO > Service, Maintenance and Technical Discussion

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pontiac GTO Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome