What is "crankwalk"?

[Jet Black]

I heard this was a big problem with DSM's. I was wondering what exactly it was.

Thanks

[Strahan]

Apparently it's a problem with the crankshaft aquiring some horizontal play in the 2G Eclipses.

http://forums.evolutionm.net/showthread/t-12790.html

Google is your friend

[8ggalant]

yea i was told it happens becuz a person rides the clutch too much...the horizontal play is why the they call it crank walk....cuz the crank "walks" outta place....but yea its not juss 2gs...my 1g awd did it too

[Gir]

http://www.magnusmotorsports.com/crankwalktheory.htm

Crankwalk is a condition in 2g Eclipse 4g63's that causes the crank to actually "walk" horizontally in the block, bending all kinds of stuff and breaking even more stuff. It only happens naturally (i.e. from the factory) in about 3% of 2g 4g63's, and sometimes in other 4g63's that are driven very hard, for example my buddy's 97 Eclipse GST. Crankwalk sucks, it means replacing the entire motor, and sometimes even the tranny.

[Gir]

Crankwalk is a condition in 2g Eclipse 4g63's that causes the crank to actually "walk" horizontally in the block, bending all kinds of stuff and breaking even more stuff. It only happens naturally (i.e. from the factory) in about 3% of 2g 4g63's, and sometimes in other 4g63's that are driven very hard, for example my buddy's 97 Eclipse GST. Crankwalk sucks, it means replacing the entire motor, and sometimes even the tranny.

3%? I think your claim is slightly off. Ask nearly an 2g car owner if their clutch was ever stuck or just not working right. Then get under there and check the thrust bearing clearance and I can nearly gurantee you that the motor will be out of spec. The only reason you hear about 3% maybe is becuase that is all the percentage that makes up the tuner market and realizes that the problem exists. Other people just seem to think their clutches are going out. I think that the number is a near certainty of crankwalk. If you run the car on a normal basis it will almost certainly get it in due time. So I'd estimate the number to be well over 50%. Given that every 2g I have yet to come across has it. 1gs are very VERY rare walkers. Usually the reason for those walking is from a poor clutch install. A guy walked a 4g63/64 hybrid on DSM talk, only to find out from everyone that he put his motor together wrong and that caused it to walk in 700 miles.

[JiP]

So it doesnt happen on a/t models? I could never get a clear answer on crankwalk most common answer I get as to a cause are oil squirters.

Now when you get really bad crank walk, I assume as things get worse if they went un diagnosed, I herd it eats your crank sensor up...how does the shaft play horizontaly cause the sensor to get eating up?

<div class='quotetop'>QUOTE(JiP)</div><div class='quotemain'>So it doesnt happen on a/t models? Â*I could never get a clear answer on crankwalk most common answer I get as to a cause are oil squirters.

Now when you get really bad crank walk, I assume as things get worse if they went un diagnosed, I herd it eats your crank sensor up...how does the shaft play horizontaly cause the sensor to get eating up?</div>
i don't think the tranny really has anything to do with it. I could be wrong, i guess...but i doubt it.

The crank doesn't move horizontally, in a sense....it's kind of like a spirograph...it rotates as it revolves, like the moon. lol....it rotates in little circles as it revolves around a center "axis." this motion will actually knock the CPS off the car.

[JiP]

A guy on 4g64 group just crankwalked his 4g64 hybird non trubo, and he does have a m/t. Every case I have heard about always involves a m/t but then again most people who are into all this performance and racing shit with a 2g usualy have manuals.

[g96nt]

travis did NOT crankwalk his 4g64...

the wear his bearings Showed is TYPICAL for a motor starved of oil even for SECONDS....(remember he spoke About ZERO oil-pressure a Day before?

sometime.. I'll show you the ones I pulled from my 4g63 when my oil filter backed off @6500..and Ran<5psi for ~15-seconds..

people Are quick to blame CW..but I don't See it in his motor...
and he knows this... As we've spoken A Few Times Since.

[weapon_x]

Crankwalk is most common in 95 and 96 DSM's, but can still happen to the later models. My opinion on why it happens is because of thrust bearing design. This was changed on the 97-ups so I don't really think that it is a coincidence. It happens on MT cars especially if they run an aftermarket clutch. The higher holding pressure provided by the perssure plate on most clutch kits puts extra stress on the rotating assembly. On 2g DSM's it will cause the crank to eventually back into the crank sensor and cause the car to shut off. On 1g DSM's it is rare compared to 2g's, but it can still happen.

[Elwenil]

<div class='quotetop'>QUOTE(ScootinIntegra)</div><div class='quotemain'>i don't think the tranny really has anything to do with it. I could be wrong, i guess...but i doubt it.

The crank doesn't move horizontally, in a sense....it's kind of like a spirograph...it rotates as it revolves, like the moon. lol....it rotates in little circles as it revolves around a center "axis." this motion will actually knock the CPS off the car.</div>

Actually the crank slides back and forth inside the block. In an I4 installed in the car this would mean it shifts back and forth form passenger side to driverside. This happens in ALL engines. V8's, V6's I6's, V12's, you name it. The key is to keep it in check. The problem is usually caused by too much clearance between the crank thrust surface, and the main thrust bearing. This can be from wear, or from poor factory tolerances. You see it more in manual transmission cars because of the force the clutch system exerts on the crankshaft itself. Automatics still have the condition, but it is less of a problem, since the torque converter doesn't apply any direct force to the crankshaft flange and it can move in and out of the tranny with the crankshafts movement. Most race engines with an automatic use aluminum or Tri-Metal main bearings and race engines with manual transmissions use Babbit bearings to help hold up better under the force. I've never built a manual "race" engine, so don't ask me how this works. On the same note, there is a such thing as "cam walk" also. I think I've heard of some Honda's having this problem, but again it is present in all engines. Small block Chevy racers use a little spring loaded "button" inside the timing chain cover to push back against the cam to help keep it from walking. Just my .02

[JiP]

<div class='quotetop'>QUOTE(g96nt)</div><div class='quotemain'>travis did NOT crankwalk his 4g64...

the wear his bearings Showed is TYPICAL for a motor starved of oil even for SECONDS....(remember he spoke About ZERO oil-pressure a Day before?

sometime.. I'll show you the ones I pulled from my 4g63 when my oil filter backed off @6500..and Ran<5psi for ~15-seconds..

people Are quick to blame CW..but I don't See it in his motor...
and he knows this... As we've spoken A Few Times Since.</div>

Ah my mistake, last I remember he pulled it apart and it showed signs of crankwalk but that was quite a while ago he's never on aim anymore so I dont talk to him much lately.

[JiP]

<div class='quotetop'>QUOTE(weapon_x)</div><div class='quotemain'>Crankwalk is most common in 95 and 96 DSM's, but can still happen to the later models. Â*My opinion on why it happens is because of thrust bearing design. Â*This was changed on the 97-ups so I don't really think that it is a coincidence. Â*It happens on MT cars especially if they run an aftermarket clutch. Â*The higher holding pressure provided by the perssure plate on most clutch kits puts extra stress on the rotating assembly. Â*On 2g DSM's it will cause the crank to eventually back into the crank sensor and cause the car to shut off. Â*On 1g DSM's it is rare compared to 2g's, but it can still happen.</div>

Is it just the thrust bearing itself or other details within the design of the block? If its just thrust bearing design itself, would it be possible to change the bearing on an early 2g with a 97 up?

I dont know too much about the bottom end of the 4g64/63 (yet anyway), so if thats a stupid question feel free to call me a noob.

[BlankMan]

So crank walk isn't what you do to get to the crack house?

Sorry, feeling kinda silly.

J

[UncleMeat]

it can happen to more than 2g eclipses, any of the 7 bolt motors can crankwalk, even the evo7 bolts or 4g64's

if you could use a 6bolt i would do it

6g's and 7g's both can use 6bolt 2.0's or 6bolt 2.4's

if i were going to build a 6g or 7g i would make sure it had a 6bolt in it, especially if i were building a motor with internals, or working on a semi high mileage block

[pornstar]

hey i dont mean to bring this back up
but from what i've read... i still dont quite understand what the symptoms are of crankwalk
how will the car feel when its "crankwalking" ... or whatever the term is...

[FRCFD6]

crank walk is caused by lack of maintenance on mitsus 4g63. Dirty oil will make the oil squirters stay on at all times, which causes low oil pressure. the low oil pressure will end up causing the failing of the thrust bearing and the crank will start "walking "

[sethmo]

There is no real way to tell if you car is experiencing crankwalk, symtoms are usully difficult to diagnose untill major damage occures. Some symptoms are that when you are turning a left corner the clutch will often ‘stick’down, this is often a sign of crankwalk. Other symptoms include rough or poor clutch engagement, inconsistant engagement height, ticking noises, difficult shifting, and variing pedal height or pressure. Another symptom is having the engine RPM decrease significantly when the clutch pedal is depressed. As you add more and more horsepower to your engine, the greater chance you have of getting crankwalk.

If you have an automatic g, chances are, you will never experience crankwalk...

Turn you steering wheel hard to the right and stab in the clutch while driving. If your car dies, you're most likely crankwalking.