Parked car rolling while in gear!
#21
Melting Slicks
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I love these folks with their "no way that is possible" comments..
My FRC will absolutely not stay put with just the trans in gear.. Yes, my motor is very strong, 415HP with minor mods.. It's all about physics - this isn’t your 4 cylinder - 2800lbs daily driver.
Just make sure the p-brake works, or you will incur damage sooner or later.
My FRC will absolutely not stay put with just the trans in gear.. Yes, my motor is very strong, 415HP with minor mods.. It's all about physics - this isn’t your 4 cylinder - 2800lbs daily driver.
Just make sure the p-brake works, or you will incur damage sooner or later.
I won't say "no way possible," but there certainly is no normal reason a C5 should roll in 1st or reverse. Hell, my GF's 2.3L Mazda won't roll in 1st on a normal grade.
For what it's worth, my dailey driver is an 04 6 speed GTO. On a reasonably steep grade in 5th gear it will inch backward tooth by tooth.This will not happen if I leave it in reverse. I believe reverse is the largest and strongest gear and should hold the car. Owner's manuals always say to put the car in reverse when parking on a grade.
#22
Le Mans Master
^^^ Disagree, but no time to argue the point.
To the OP, due to the p-brake design it seems to be more effective in the reverse direction, so if you are on a steep hill, park it nose-up.
To the OP, due to the p-brake design it seems to be more effective in the reverse direction, so if you are on a steep hill, park it nose-up.
#23
Melting Slicks
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#24
Race Director
I was just about to post that... My money is on the Diff/Posi
#25
Race Director
Hey guys, I just bought my 98 6spd last week. I noticed during the test drive the parking brake was not working. I've already searched for the fix to that problem.
The real problem is my car rolls backwards in any gear. I saw it is recommended to park in reverse. Still rolls. And when I say rolls I mean like I have the clutch pedal depressed.
I don't understand why the transmission is not holding. Is the engine compression bad? 85k miles. Is the clutch slipping?
I understand the importance of the parking brake and will always use it once I adjust it, but I've never seen a car roll like this before. Any ideas?
The real problem is my car rolls backwards in any gear. I saw it is recommended to park in reverse. Still rolls. And when I say rolls I mean like I have the clutch pedal depressed.
I don't understand why the transmission is not holding. Is the engine compression bad? 85k miles. Is the clutch slipping?
I understand the importance of the parking brake and will always use it once I adjust it, but I've never seen a car roll like this before. Any ideas?
Take a look at this post on another forum...you need to scroll to the top to see the pictures to understand the concept.
http://www.nastyz28.com/forum/showthread.php?p=1158892
Especially this response #4... This all makes sense... At no load...ie. Car off.. there is not enough preload on the Posi clutches... Hence the car rolls..
When driving... there is enough force on them to keep the car driveable..
Just my $.02 I could be wrong..
Last edited by chuckster; 04-11-2008 at 04:23 PM.
#26
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#27
Race Director
Look at the post above.. I think this is a pretty good explanation as to the slippage but staying drivable..
#29
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No. Car seems to drive fine. Shifts fine. (needs a firm hand in first) No noise. Just rolls in gear. I am going right now to harbor frieght for a breaker bar and torque wrench (125 ft lbs!) to get the parking brake fixed.
After seeing that others have similar issues I am going to just leave it. Mine seems to be a little more pronouced though. My guess is that with 85k miles there are just slightly worn parts. Combo of trans, clutch, engine, rear end, etc.
If you see a post in the next couple of months about body damage you'll know I fogot to pull the magic handle!
After seeing that others have similar issues I am going to just leave it. Mine seems to be a little more pronouced though. My guess is that with 85k miles there are just slightly worn parts. Combo of trans, clutch, engine, rear end, etc.
If you see a post in the next couple of months about body damage you'll know I fogot to pull the magic handle!
#30
Safety Car
Study how a differential works .... I don't care what kind you look at ..... unless one drive shaft is COMPLETELY broken off the main pinion .... what the OP describes is IMPOSSIBLE if the car is in gear .... and you still could NOT drive the car .........
Let me help you morons figure this out .... you ever heard of a car (Corvette, Toyota, whatever) with an AUTOMATIC IN PARK that rolled down a hill ?????????
NO ........................
The differential is not the issue .......
Unless the OP jacked his car up so one rear wheel is off the road ... either he has a car that is doing "magical" things ... or as I said earlier .... he is not getting the car in gear.
Not possible .... he is NOT getting the car in a gear ......
#31
Melting Slicks
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Look guys .... and gals .... either the differential is so broken the car is undriveable .... or the OP is NOT GETTING THE CAR IN GEAR.
Study how a differential works .... I don't care what kind you look at ..... unless one drive shaft is COMPLETELY broken off the main pinion .... what the OP describes is IMPOSSIBLE if the car is in gear .... and you still could NOT drive the car .........
Let me help you morons figure this out .... you ever heard of a car (Corvette, Toyota, whatever) with an AUTOMATIC IN PARK that rolled down a hill ?????????
NO ........................
The differential is not the issue .......
Unless the OP jacked his car up so one rear wheel is off the road ... either he has a car that is doing "magical" things ... or as I said earlier .... he is not getting the car in gear.
Not possible .... he is NOT getting the car in a gear ......
Study how a differential works .... I don't care what kind you look at ..... unless one drive shaft is COMPLETELY broken off the main pinion .... what the OP describes is IMPOSSIBLE if the car is in gear .... and you still could NOT drive the car .........
Let me help you morons figure this out .... you ever heard of a car (Corvette, Toyota, whatever) with an AUTOMATIC IN PARK that rolled down a hill ?????????
NO ........................
The differential is not the issue .......
Unless the OP jacked his car up so one rear wheel is off the road ... either he has a car that is doing "magical" things ... or as I said earlier .... he is not getting the car in gear.
Not possible .... he is NOT getting the car in a gear ......
#32
Safety Car
Al Gore claimed to be the founder of the "Information Highway" ..... yeah ... right ..... what he forgot to point out is that there are a lot of garbage trucks out there that deliver ... well .... garbage information.
#33
Melting Slicks
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Fair complaint ... though they are two of my favorite words ..... it just gets me REALLY irritated when I see "information" posted that is so incorrect ......
Al Gore claimed to be the founder of the "Information Highway" ..... yeah ... right ..... what he forgot to point out is that there are a lot of garbage trucks out there that deliver ... well .... garbage information.
Al Gore claimed to be the founder of the "Information Highway" ..... yeah ... right ..... what he forgot to point out is that there are a lot of garbage trucks out there that deliver ... well .... garbage information.
#34
Quote...
Let me help you morons figure this out .... you ever heard of a car (Corvette, Toyota, whatever) with an AUTOMATIC IN PARK that rolled down a hill ?????????
Ok, this moron has...
My wife and I were coupling in the front seat of our Toyota Corona. I forgot to set the hand brake. At a most inopportune time the parking pawls on the A/T could no longer hold back the weight of the rocking car. We were in the Tahoe area and parked facing a very big cliff. We managed to get the brakes before going off the cliff.
Further..
CONSUMER COMPLAINT: ODI Case Number: 10223692
Component: POWER TRAIN:AUTOMATIC TRANSMISSION
Details: TL*THE CONTACT OWNS A 1998 HONDA PRELUDE. THE CONTACT PARKED THE VEHICLE IN HER DRIVEWAY, REMOVED THE KEY FROM THE IGNITION, AND EXITED THE VEHICLE. WHEN SHE RETURNED TO ENTER THE VEHICLE, IT BEGAN TO ROLL OUT OF THE DRIVEWAY. THE CONTACT WAS DRAGGED BY THE VEHICLE, BUT SHE WAS ABLE TO LET GO AND ROLL ON THE PAVEMENT. THE VEHICLE STRUCK THE MAILBOX AND CAME TO A STOP WHEN IT STRUCK A POLE. THE VEHICLE WAS TAKEN TO THE DEALER ON JANUARY 30, 2006 FOR NHTSA CAMPAIGN ID NUMBER 05V025000 (ELECTRICAL SYSTEM:IGNITION:SWITCH). THE MANUFACTURER WANTS THE CONTACT'S INSURANCE COMPANY TO INVESTIGATE THE FAILURE AND NOTIFY THEIR LEGAL DEPARTMENT WITH THE RESULTS. THE CONTACT SUSTAIN INJURIES TO HER LEFT AND RIGHT SIDE. A POLICE REPORT WAS FILED. THE POWERTRAIN AND SPEED WERE UNKNOWN. THE CURRENT AND FAILURE MILEAGES WERE 115,320.
Occurrences: 1 Injuries: 1
Fail Date: 04/04/2008 Deaths: 0
Date added to datbase: 4/8/2008
Whatever dood...
Let me help you morons figure this out .... you ever heard of a car (Corvette, Toyota, whatever) with an AUTOMATIC IN PARK that rolled down a hill ?????????
Ok, this moron has...
My wife and I were coupling in the front seat of our Toyota Corona. I forgot to set the hand brake. At a most inopportune time the parking pawls on the A/T could no longer hold back the weight of the rocking car. We were in the Tahoe area and parked facing a very big cliff. We managed to get the brakes before going off the cliff.
Further..
CONSUMER COMPLAINT: ODI Case Number: 10223692
Component: POWER TRAIN:AUTOMATIC TRANSMISSION
Details: TL*THE CONTACT OWNS A 1998 HONDA PRELUDE. THE CONTACT PARKED THE VEHICLE IN HER DRIVEWAY, REMOVED THE KEY FROM THE IGNITION, AND EXITED THE VEHICLE. WHEN SHE RETURNED TO ENTER THE VEHICLE, IT BEGAN TO ROLL OUT OF THE DRIVEWAY. THE CONTACT WAS DRAGGED BY THE VEHICLE, BUT SHE WAS ABLE TO LET GO AND ROLL ON THE PAVEMENT. THE VEHICLE STRUCK THE MAILBOX AND CAME TO A STOP WHEN IT STRUCK A POLE. THE VEHICLE WAS TAKEN TO THE DEALER ON JANUARY 30, 2006 FOR NHTSA CAMPAIGN ID NUMBER 05V025000 (ELECTRICAL SYSTEM:IGNITION:SWITCH). THE MANUFACTURER WANTS THE CONTACT'S INSURANCE COMPANY TO INVESTIGATE THE FAILURE AND NOTIFY THEIR LEGAL DEPARTMENT WITH THE RESULTS. THE CONTACT SUSTAIN INJURIES TO HER LEFT AND RIGHT SIDE. A POLICE REPORT WAS FILED. THE POWERTRAIN AND SPEED WERE UNKNOWN. THE CURRENT AND FAILURE MILEAGES WERE 115,320.
Occurrences: 1 Injuries: 1
Fail Date: 04/04/2008 Deaths: 0
Date added to datbase: 4/8/2008
Whatever dood...
#35
Race Director
An Automatic transmission does not roll because it uses a Parking Pawl. It is a ratchet that locks the transmission gears.. Ever throw an automatic in park before a complete stop? BDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD...
And the car is going into gear.. Its a terrible assumption that the Original poster is so stupid that he cannot get his tranmission to accept ANY gear to park in..
Grow up...
Nobody bothered to look at my Post #25
http://forums.corvetteforum.com/show...6&postcount=25
By the way.. to the original poster.. I'd be curious if you can leave an EVEN Burnout stripe. If you dont want to be that drastic.. Jack up the rear of the car till the wheels are off the ground. Put the car in 1st gear.
The get 2 people and each of you grab a tire and at the same time turn them in the SAME direction... I'll lay you a Bet you can turn them. If so... The POSI is FECKED!
Last edited by chuckster; 04-14-2008 at 03:22 PM.
#36
Burning Brakes
I've seen lots of posts about dirty clutch fluid causing the clutch pedal to stick. Could this be the cause? Maybe the clutch is slightly engaged, allowing the car to roll?
#37
Drifting
First, it's not a broken axle or differential. If either had failed so that car would roll, it couldn't be driven either as no power could be put to the ground (unless it's got something like a Detroit Locker in it).
I suspect a shifting collar on the tranny is worn and allowing the tranny to shift into neutral when sitting on a slope.
I suspect a shifting collar on the tranny is worn and allowing the tranny to shift into neutral when sitting on a slope.
#38
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Some basic differential theory?
Most vehicles have an open diff that uses spider and side gears. You can spin just one wheel but that wheel goes 2X as fast as the speedo is reading. If you jack the car up in park or in gear and spin one wheel forward the other one goes backwards with no real resistance.
A posi diff is very similar to an open diff except it has clutches in between the side gears and the case. When the spider gears try to turn the side gears they get pushed out into the clutches and the clutches hold the side gears and case together making power go to both wheels. Most of the power goes through the spider and side gears and the clutches are just there to provide enough resistance to make both wheels turn together. If you have a weak posi or enough of a traction difference between the wheels you can still spin one wheel.
So, in either case, the diff will not allow the car to move without the pinion moving unless something is broken or one or more of the wheels is sliding.
If the car in question is driving right and seems to be making full power then there really can't be a drivetrain problem so just fix the emergency brake. A drivetrain problem that would let a car just coast while in gear would have to be a pretty major problem that would be noticeable when driving.
Peter
Most vehicles have an open diff that uses spider and side gears. You can spin just one wheel but that wheel goes 2X as fast as the speedo is reading. If you jack the car up in park or in gear and spin one wheel forward the other one goes backwards with no real resistance.
A posi diff is very similar to an open diff except it has clutches in between the side gears and the case. When the spider gears try to turn the side gears they get pushed out into the clutches and the clutches hold the side gears and case together making power go to both wheels. Most of the power goes through the spider and side gears and the clutches are just there to provide enough resistance to make both wheels turn together. If you have a weak posi or enough of a traction difference between the wheels you can still spin one wheel.
So, in either case, the diff will not allow the car to move without the pinion moving unless something is broken or one or more of the wheels is sliding.
If the car in question is driving right and seems to be making full power then there really can't be a drivetrain problem so just fix the emergency brake. A drivetrain problem that would let a car just coast while in gear would have to be a pretty major problem that would be noticeable when driving.
Peter
#39
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I agree that maybe I didn't put the car in gear the first time or possibly the second. But when I focus real hard and sit in the driveway for 20-30 min trying to park the car, I think I would have got in gear at least once. And then I used the search and backed the car out and tried each and every gear again focusing on reverse. So again maybe it's operator error, but I doubt it. I drove the car about 75 miles today, and I wasn't Sunday driving either. Absolutly no indication of any problem whatsoever
During my test drive from the brake work I may have let the clutch out a little too fast with the rpm's a little too high and squeeked the tires. (about 5ft!!) Felt like the diff was working fine.
Then I backed in and tried it with the nose facing downhill. The car was very very barely moving. And the same for reverse.
Good news is my new tools work great and now so does my parking brake!
During my test drive from the brake work I may have let the clutch out a little too fast with the rpm's a little too high and squeeked the tires. (about 5ft!!) Felt like the diff was working fine.
Then I backed in and tried it with the nose facing downhill. The car was very very barely moving. And the same for reverse.
Good news is my new tools work great and now so does my parking brake!