FAQ : What is Crankwalk?

Crankwalk is a term given to excessive play between your crankshaft and thrust bearing, which will put excessive side load or uneven load on your bearings and in time could break your crank position sensor. While this is a condition that can effect any motor, it’s most commonly associated with the 4G63 found in the second generation Mitsubishi Eclipse ( 1995-1999 ) year ranges.

There are plenty of theories behind the root cause of this issue, from miscast crankshafts, defective bearings, incorrect specifications or blocks causing the problem, everyone has a theory or hypothesis behind crankwalk. Mitsubishi has several versions of redesigned crankshaft thrust bearings that are supposed to diminish the probability of crankwalk, but if you own a 7 bolt motor, you are best served by swapping in a earlier version of this 4G63 motor.

The first generation of the 4G63 found in the 1989-1994 Eclipse/Talon/Laser is not known to have crankwalk issues, but it’s important to remember that this condition is not Mitsubishi or 4G63 specific.

Symptoms of Crankwalk

• Clutch weirdness, improper pedal pressure, strange disengage and engage points
•  Ticking or strange noise from the pulley side of the engine when clutch is depressed.
• Crank Angle Sensor errors ( check engine light )
•  Difficulty shifting
• RPMS decreasing significantly when clutch pedal is depressed.
• Clutch does not return or “sticks” to the floor after being depressed
• Clutch does not return or “sticks” to the floor during left hand turns

It can be difficult to tell if a particular car is experiencing crankwalk. Symptoms are usually indirect and difficult to diagnose until major damage occurs and can also lead to misdiagnosis from inexperienced mechanics or tuners.

Ticking noises from the pulley side of your motor usually means that the crankshaft is moving laterally so much as to make contact and subsequently destroy your 4G63 crankshaft position sensor. Unfortunately, if you are hearing this sound the crankshaft position sensor is in need to replacing, which in reality means that your motor should be swapped.

Failure to properly diagnose this symptom may lead some mechanics to simply replace your crankshaft position sensor, which does not resolve the underlying issue in any manner but instead masks the problem until it ultimately fails again.

Is there a recall or TSB regarding the crank walk problem?

• It appears that Mitsubishi built many 2G engines that have this ailment, but sadly no there currently is no recall for crankwalk. 1G owners ( 1990 – 1994 ) do not generally need to worry, as there aren’t as many problems with crankwalk in those cars. Mazda Miatas are one of the few other cars known to have issues like this from the factory

How can I tell if I have crankwalk?

• Its not easy to diagnose whether or not your car has crankwalk. It can be difficult to tell if a particular car is experiencing symptoms of crankwalk. Refer to our symptoms list above.

What should I do to check or prevent crankwalk?

• We recommend using a oil filter from a 1g at all times.. A larger oil filter will provide for better filtration, preventing oil squirters from clogging.
• Pay attention to what your car is doing.. keep an eye on your oil pressure, and make sure you perform proper maintenance at the scheduled times.
• Keep an open mind about it. Crankwalk isnt something you can control, people get it stock or modded. Theres no bearing on whether mods cause it or not.
• We always recommend building a 6 bolt or swapping in a 6 bolt. Never build a 7 bolt or swap in a reconditioned one.

How can I check my crank end play?

Measuring crankshaft play is relatively straightforward as long as you have the space and a proper feeler gauge as shown above. You will be measuring the play between your thrust bearing when using a prybar to gently move the crankshaft in a lateral motion.

This can be accomplished by removing the oil pan and gently prying the flywheel towards the pulley side of the motor. Make sure you do not damage the rear main seal housing, which is aluminum, not iron like your block

• Pro Street Staff
• www.prostreetonline.com