02 zo6 crank walk????
07-14-2013, 12:15 PM
#1
Teching In
Thread Starter
iTrader: (-1)
Join Date: Mar 2013
Posts: 48
Likes: 0
Received 0 Likes
on
0 Posts
02 zo6 crank walk???? Posting for a buddy...he went thru 3 clutches before he noticed he has crank walk...what can cause this car still drives with nothing weird going on but the clutch not ingauging...
If you look up z06 crank walk it comes up only 7 seconds long...thanks for Any help..
If you look up z06 crank walk it comes up only 7 seconds long...thanks for Any help..
07-14-2013, 07:22 PM
#5
Huh???..This ain't no 2JZ yo. "clutch not engaging," makes no sense. Clutch is always engaged. If the crank walks far enough for the clutch to always be disengaged, it has walked over 1/4"+. It would have to compress the PP fingers & have completely retracted the slave cylinder.
I don't doubt that he physically measured crank walk. I just doubt that it's moving that far without other internal engine damage. The thrust bearing is either damaged or thrust clearance was not initially measured & set up correctly. He needs to take it apart & look.
07-14-2013, 08:17 PM
#6
I've read this before: On cold starts, you should always start the vehicle in neutral with your foot off the clutch. If you continually start a manual shift vehicle in gear with the clutch depressed, the (dry) thrust bearing being in a high-load situation with zero lubrication, will eat itself up.
07-14-2013, 11:24 PM
#7
TECH Fanatic
I've read this before: On cold starts, you should always start the vehicle in neutral with your foot off the clutch. If you continually start a manual shift vehicle in gear with the clutch depressed, the (dry) thrust bearing being in a high-load situation with zero lubrication, will eat itself up.
OP: Has that motor ever been torn down? I can't imagine that it just randomly started dropping clutches one day unless something changed in the setup.
Last edited by ryridesmotox; 07-14-2013 at 11:32 PM.
Trending Topics
07-15-2013, 12:18 AM
#8
Teching In
Thread Starter
iTrader: (-1)
Join Date: Mar 2013
Posts: 48
Likes: 0
Received 0 Likes
on
0 Posts
Huh???..This ain't no 2JZ yo. "clutch not engaging," makes no sense. Clutch is always engaged. If the crank walks far enough for the clutch to always be disengaged, it has walked over 1/4"+. It would have to compress the PP fingers & have completely retracted the slave cylinder.
I don't doubt that he physically measured crank walk. I just doubt that it's moving that far without other internal engine damage. The thrust bearing is either damaged or thrust clearance was not initially measured & set up correctly. He needs to take it apart & look.
I don't doubt that he physically measured crank walk. I just doubt that it's moving that far without other internal engine damage. The thrust bearing is either damaged or thrust clearance was not initially measured & set up correctly. He needs to take it apart & look.
Just tryna see what it can be before we pull to get a idea...thanks
07-15-2013, 12:21 AM
#9
Teching In
Thread Starter
iTrader: (-1)
Join Date: Mar 2013
Posts: 48
Likes: 0
Received 0 Likes
on
0 Posts
I haven't been able to start a manual transmission car that was made less than 25 years ago without depressing the clutch in neutral or in gear. The clutch position sensor won't let you start the engine without the clutch depressed. In my old 55 chevy and 59 ford pickups I could crank them over, in gear with my foot off the clutch and the starter would yank the truck forward. I can only assume I misunderstood your post and what you are trying to say (wouldn't be the first time I didn't read something correct), and I hope that is the case.
OP: Has that motor ever been torn down? I can't imagine that it just randomly started dropping clutches one day unless something changed in the setup.
OP: Has that motor ever been torn down? I can't imagine that it just randomly started dropping clutches one day unless something changed in the setup.
07-15-2013, 09:27 AM
#10
He went thru two stock clutches...then went with a twin disk mcleod and now it won't engaged enough for him to go thru the gears....car has 90k miles and has never been apart..he says he can grab the pulley and move the crank back n forth ...you can see in the video..
Just tryna see what it can be before we pull to get a idea...thanks
Just tryna see what it can be before we pull to get a idea...thanks
Got to pull engine. Post pics. Have never seen a thrust bearing jacked up to that level.
07-15-2013, 11:26 AM
#11
TECH Fanatic
iTrader: (8)
Join Date: Nov 2009
Location: phx the cactus patch
Posts: 1,095
Likes: 0
Received 13 Likes
on
13 Posts
I thought You said there was a video,,,,,,,,,,,,remember in school whenever there was a video everyone kinda woke up only to kinda take a little nap once the lights went down ,,,,,,,,ha ha ha ,,,,,,,so where's our video ????
ryridesmotox ,,,,I imagine He's dropping clutches because He's young and racing anything and everything and even when nobody else is around
ryridesmotox ,,,,I imagine He's dropping clutches because He's young and racing anything and everything and even when nobody else is around
Last edited by chrisfrost; 07-15-2013 at 11:32 AM.
07-15-2013, 08:44 PM
#12
I haven't been able to start a manual transmission car that was made less than 25 years ago without depressing the clutch in neutral or in gear. The clutch position sensor won't let you start the engine without the clutch depressed. In my old 55 chevy and 59 ford pickups I could crank them over, in gear with my foot off the clutch and the starter would yank the truck forward. I can only assume I misunderstood your post and what you are trying to say (wouldn't be the first time I didn't read something correct), and I hope that is the case.
OP: Has that motor ever been torn down? I can't imagine that it just randomly started dropping clutches one day unless something changed in the setup.
OP: Has that motor ever been torn down? I can't imagine that it just randomly started dropping clutches one day unless something changed in the setup.
Back to the topic at hand, dry-starting a loaded thrust bearing will damage it. Doesn't seem like there's an elegant solution around it though... Best advice is to add some pressure feed grooves to oil the thrust (at least the rear face) while running if not already there.
http://www.motor.com/article.asp?article_ID=1656
http://www.genepop.com/2012/01/Cause...aring-Failure/
First couple Google links seem to blame poor machiining/installation or a "misplaced foot" for the majority of wear issues...
07-15-2013, 10:35 PM
#14
Teching In
Thread Starter
iTrader: (-1)
Join Date: Mar 2013
Posts: 48
Likes: 0
Received 0 Likes
on
0 Posts
I thought You said there was a video,,,,,,,,,,,,remember in school whenever there was a video everyone kinda woke up only to kinda take a little nap once the lights went down ,,,,,,,,ha ha ha ,,,,,,,so where's our video ????
ryridesmotox ,,,,I imagine He's dropping clutches because He's young and racing anything and everything and even when nobody else is around
ryridesmotox ,,,,I imagine He's dropping clutches because He's young and racing anything and everything and even when nobody else is around
07-15-2013, 11:55 PM
#15
TECH Senior Member
iTrader: (96)
Join Date: Aug 2007
Location: Turnin' Wrenches Infractions: 005
Posts: 24,240
Likes: 0
Received 79 Likes
on
70 Posts
Crank endplay should be .004-.008. At .040, or 5 times the maximum allowed, the crank counter-weights are rubbing the block itself. Lots of things can cause this issue, getting ready to do some reading.
07-16-2013, 07:44 AM
#16
No, you didn't misunderstand me. I definitely read that somewhere and (of course) cannot find it now. I forget ya'll drive new junk with interlocks on everything. I prefer old junk and am sometimes prone to flashing back a few decades without thinking. Sucks to get old, I don't recommend it at all. BTW, I've never had a car move while starting it in neutral with the clutch out. If you did, something was definitely maladjusted.
Back to the topic at hand, dry-starting a loaded thrust bearing will damage it. Doesn't seem like there's an elegant solution around it though... Best advice is to add some pressure feed grooves to oil the thrust (at least the rear face) while running if not already there.
Back to the topic at hand, dry-starting a loaded thrust bearing will damage it. Doesn't seem like there's an elegant solution around it though... Best advice is to add some pressure feed grooves to oil the thrust (at least the rear face) while running if not already there.
07-16-2013, 08:25 PM
#17
I think you're lost in more ways than one. We're talking about a C5 Z06, not some 40 year old POS. You start it in any gear you like, as long as the clutch pedal is depressed. I what you suggest were true, EVERY manual trans vehicle built in the last few decades would have premature engine failures - all 20+ million of them
But, I guess if ya had $70G to drop on a big fine "C5 Z06" ya prolly wouldn't be too worried about dropping cash on repairs. Hmmm, maybe that's why I could afford to retire at 57... Happy days, bro! 
07-17-2013, 02:51 AM
#20
TECH Fanatic
OP, did he get the motor torn down yet to inspect to see what kind of damage (if any) has been done to the block? If it is that far out of spec some bad **** could be going on there.
