Crank Walk :(
 

hey everyone well it looks as if i have a crank walk situation with my car. I decided to measure the movement i found in the crank with a magnetic dial indicator due to my inconsistent pedal and to my dismay came up with some astonishingly bad numbers. Spec on movement is .030mm range i believe, and when i measured it was inbetween .020-.024in. so obviously this is way way out of spec. My question is this, to replace the thrust bearing #5 right? Do i have to pull the engine and split it or can i pull the pan and get to it from the bottom? I really hope I can get to it from the bottom or it doesnt look like the svx will be going anywhere for a long time...ANy and all help is greatly appreciated. And for more of an explanation there is a thread a few spaces down that details the events from a while ago that started all this. thanks in advance for any and all help with the matter

I think you're going to have to split the case. Does the inconsistent pedal feel make the car impossible to drive? If not, then I'd just drive it.

not trying to be dumb, but how was this measured? If the crank pully/ballancer was any part of the reference/measure point, throw the numbers out. The two peice unit has lots of slop and commonly comes apart.

just my $0.02

it doesnt make the car immobile but it does cause a sticky clutch pedal feel. I didnt want to just drive on it because i figured when it catastrophically failed then it would cause much more engine damage then if it was just a bearing that needed to be replaced. If this isn't the case then i'll keep working on the car getting it ready for the next track day at sebring on jan. 28, i just dont want to drive an hour and half down there race all day and then have the car crap out on me. And it was measured with a mag. dial indicator with the needle inbetween the first and second rib of the crank pulley. Before dismissing it b/c of where it was measured keep in mind that i can hear very distinctly and see the movement. Its not just the pulley flexing if it was i doubt i would hear the distinct "click" from inside the engine. I hope im wrong but doubt it. Does anyone have any other suggestions on how to measure it then if the crank is so unreliable? I figured that was the only way.

You may be able to get rid of the inconsistent feel by adjusting the clutch pedal. If there is not enough free play in the clutch pedal, the master cylinder piston does not retract far enough to open up the hydraulic line to the clutch fluid reservior. In effect, you create a sealed system consisting of only the fluid in the clutch hydraulic line itself. As the fluid heats up, it expands and because it cannot expand into the reservior, it instead pushes on the slave cylinder piston and causes the clutch to become partially disengaged and the clutch will fully disengage at different pedal travel locations.

i really dont think its a matter of clutch adjustment because until it sticks the clutch travel and feel is perfect. Once it sticks though the clutch engages and disengages just doesnt give me full pedal travel.(atleast i feel like it is getting full engage/disengagement) So whats gonna happen if i keep driving on it like it is? Probably engine damagae when a total failure happens correct?So im assuming i shouldnt go to sebring unless its fixed?

Just from reading your account, I seriously doubt that this forged steel crank went for a 'walk'!

http://www.subaru-svx.net/photos/fil...etkd/29130.jpg

I also agree with what Chris mentioned - the crank pully/harmonic balancer is infamous for seperating into two pieces. This happens quite frequently in high mileage SVXs.

I have yet to hear of crankwalk in an EG33 (including the heavily modded ones used in dune buggy's). This isn't a 2nd gen dsm.... ;)

-Chike

true i understand this is not a dsm which are known for crankwalk apparently from what i ve been hearing. If you really want to make me believe this isnt crankwalk do a favor for me, go to your car with a pry bar and pry off the left side of the crank pulley using the bolt there on the belt tensioner i believe as a pivot point. Tell me if you can hear a distinct clunk/click sound in the middle to back of the engine. Also explain to me why then an entirely new clutch hydraulic system bleed numerous times and ways still has a anything but consisten clutch pedal. It makes sense to me after thinking about it, so i was just mainly curious as to wether or not it could be done without taking the engine apart. Cause i seriously doubt if you pry on your crank pulley you'll hear a sound in the engine when pulling it out and pushing it in(towards the back of the car). Please tell me what your results are i would really love for it to be a crank pulley even though i definitely inspected mine and it was fine, and its still operating fine from what i can tell. There is no wobble or anything irregular about it. I appreciate any and all help, and have a good holiday weekend.

Stop. Think. Each time you release the clutch the pressure is transmitted through the throw-out bearing, pressure plate and flywheel. This, in turn, pushes the crank forward each and every time. So, while you may or may not have crank walk, the only thing it would cause at the pedal is a little more travel, not an inconsistent pedal.

If the crank has inconsistent end-play that can be felt at the clutch pedal you have a really weird problem and you should keep a bucket in the trunk - to pick up the pieces...

ok maybe im missing something here...Why then if there was too much play in the bearings allowing the crank to be pulled back further than normal when disengaging the clutch would the crank return to its original position? If it got pulled back to far and the clutch stops engagin before the crank is in its original spot wouldnt that cause a clutch pedal to not come up all the way? Also whats the noise im hearing in my engine if its not the bearings? I appreciate the help so far..I just cant seem to see why the crank would have to go back if it got pulled out so far from spec.

Just as your pushing/pulling the crank back and forth from the front pulley the pressure from the t/o bearing pushing forward into the pressure plate fingers will move the crank forward. When you release pressure on the pedal the t/o bearing quits applying pressure to the pressure plate and the crank will find its 'happy center' again. We're talking .030" here, correct? That's about the thickness of two paper matches or the gap of an average spark plug.

Regarding the source of your noise it's anyone's guess at this distance.

well if i recall correctly that is .030mm not " hence why its so out of spec. i thought anyways...