newbie question [crank walk]

[brygsx95]

I recently owned a 95 gsx, and it had 117k no crank walk. I know i have heard once your past 70k your in the clear, but thats where everyone automatically says the 7bolts are garbage. I would just have it checked out, but a reputable mechanic and see how far the crank has actually moved.

 

[need2bfast]

hello everyone i wanted to stop in and say whud up!

im looking at getting a 2g in the very near future, but i have heard somethin about "crank walk" how much power does it take to make this happen....should i just go to 6 bolt right away? thanks for the help and cant wait to be a member of the dsm community

 

[eclipsegs98911]

OK, there are about 1000 posts about crankwalk. This is so over rated. I have seen about a dozen cars to get it. It is something that you need to realize can happen. It happens on 7 bolts, it happens on 6 bolts just not as much on the 6 from what I have seen and read. I have dropped my pan and checked when I removed the balance shafts and even though the crank moves it is not enough to cry over. The HP or torque output has no relation to crankwalk happening, it is like a disease you are born with one day it just hits you but up till then there are no signs. I would purchuse the 2G like you want and just enjoy the car but keep in mind this can happen. Dont go "HOLY $HIT" if one day it happens becasue you knew it was a possibility. Modify the car make it put down 300+ hp and worry about the rods breaking before the crankwalks.

 

[Iannelli828]

Crankwalk isnt really even that common and to my knowledge once you get passed the 100k mark it is pretty much not going to happen

 

[tylermartindc]

what does it feel like when the crank walks? could it stop the car , or could it just happen a bit and eventually one day kill it?

 

[Newlogics]

what does it feel like when the crank walks? could it stop the car , or could it just happen a bit and eventually one day kill it?

As tempted as I am to say 'search damn it', I'll abide by the rules and try to lay it out for you.

First of all, a quick overview of what a crankwalk actually is, will help you understand what it does. A crankwalk is an excessive lateral play in the crankshaft. In other words, thrust bearing (which 'locates' crank horrizontally) wears down excessively and allows crank to move back and forth in addition to spinning.

Now let's see what it does.
On a 2G DSM, there is a neat little device called Crank Angle Sensor (which is part of CAM angle sensor on a 1G) located right next to crank timing plate. As a matter of fact, it overlaps it, to read crank possition. Well, when crank develps enough lateral play, it extends so far, that crank timing plate touches crank angle sensor and pretty much destroys it. That's when your car stops and you call a towtruck. In some cases internal engine damage occurs even before crank angle sensor is killed. Then you're really screwed.

Is it really that common?
Hmm. As a mechanic, I should say yes, obviously, because I see lots of cases, but then again, why would a good running 7-bolt be brought to a mechanic? So I say the truth is somewhere in the middle. Yes it happens, yes it happens more then to other cars. Definitely more then 6-bolts. As a matter of fact, I only saw one CWed 6-bolt in my shop. And it happened due to foreign objects getting in the bearings. I guess the main difference between 6-bolts and 7-bolts, is that 6-bolt can get crankwalk via influence of external factors, while *some* 7-bolts will develop CW for no apprent reason (design flaw, I have to assume at this point).

What are the symptoms?
One very commonly detected symptom is sticky clutch pedal during right turn. Since Flywheel (and thus clutch assembly) are attached to the crank, they move with the crank as well, so when you're making a sharp right turn, inertia throws crank and clutch assembly to the left, moving it away from clutch fork and release bearing, making your clutch pedal loose resistance and drop closer to the floor. That usually indicates advance stages of CW.
A very easy way to check for advace CW is to grab crank pulley and try yanking it back and fourth. You should feel excessive movement right away.

That's about all I'm willing to write for now. May be will add something later.

 

[89ColtGL]

I had the rarest crankwalk of them all 96 Spyder GST Automatic...yes AUTOMATIC
I purchased the car with 32,500mi and by 45,000mi the crankwalked leaving me stranded at 11pm on US30.

The car was mostly stock so mods don't really have an added effect. If you run an aftermarket clutch/pressure plate combo you are going to want to disable the clutchswitch.

 

[boostedinaz]

I had the rarest crankwalk of them all 96 Spyder GST Automatic...yes AUTOMATIC
I purchased the car with 32,500mi and by 45,000mi the crankwalked leaving me stranded at 11pm on US30.

The car was mostly stock so mods don't really have an added effect. If you run an aftermarket clutch/pressure plate combo you are going to want to disable the clutchswitch.

What was the crank endplay when it "walked"?

 

[89ColtGL]

What was the crank endplay when it "walked"?

Not sure of the measurement because someone else disassembled the block but the main bearings were shaved down and nearly gone.

 

[DGajre777]

Please read:
http://www.dsmtuners.com/forums/showthread.php?t=14406
http://www.dsmtuners.com/forums/showthread.php?t=90637
http://www.dsmtuners.com/forums/showthread.php?t=226858
http://www.dsmtuners.com/forums/showthread.php?t=15307
http://www.dsmtuners.com/forums/showthread.php?t=193479
http://www.dsmtuners.com/forums/showthread.php?t=178656
http://www.dsmtuners.com/forums/showthread.php?t=155738



http://www.roadraceengineering.com/walkingcrankshaft.htm

Not sure of the measurement because someone else disassembled the block but the main bearings were shaved down and nearly gone.

AWD Crankwalk check
http://www.angelfire.com/pa4/awdcrankwalk/

FWD Crankwalk check
http://www.angelfire.com/pa4/fwdcrankwalk/

http://www.angelfire.com/pa4/crankwalk/
http://www.angelfire.com/pa4/thrustbearing/

Don't say it is crankwalk, until you KNOW it is crankwalk. And remember that any motor, including a 6bolt, can crankwalk.

 

[boostedinaz]

Not sure of the measurement because someone else disassembled the block but the main bearings were shaved down and nearly gone.

Ahhhh.

Interesting.

 

[keymaster]

Well, my 7-bolt walked with almost 90k on it. .030" endplay on it when I pulled it for the 6-bolt swap.

 

[DGajre777]

There are other ways to check if you can't measure crank end play. Do a hard LEFT turn and see if your pedal sticks to the floor and listen for ticking noises in the timing belt area.

EDIT: Left turn, not right. I don't know what I was thinking.

 

[keymaster]

Actually, that would be hard LEFT turn.

 

[DGajre777]

Actually, that would be hard LEFT turn.

Yes, hard LEFT turn, not right.

Here's some more crankwalk info...

Title: What is a Crankwalk?
Description: What is a "Crankwalk" or a 'walking' crankshaft? (Is it a crank with greasy hairy legs on crutches?)

A 'crankwalk' or 'walking' crankshaft, occurs when an engine has thrust bearing failure or "blown thrust". It is a common problem with Mitsubishi 2G 4G63 2.0 DOHC (Dual Over head Cam) engines, and we have the solution.

This condition occurs when the the crank suffers excessive movement (crankshaft end play) and causes the crank angle sensor reluctor plate to come into contact with the sensor.

Symptoms associated with the crankwalk:

1. Clutch sensitivity, strange disengage and engage points.
2. Ticking or strange noise from the pulley side of the engine when clutch is depressed.
3. Crank Angle Sensor errors ( check engine light )
4. Difficulty shifting
5. RPMS decreasing significantly when clutch pedal is depressed.
6. Clutch does not return or "sticks" to the floor after being depressed

When this happens the engine will stop running, or you will notice hard shifting, or low clutch pedal. You may also hear a slight ticking noise. There are several theories about crankwalk, however there is no 'rock hard' evidence that officially points out this problem. The movement can be from the crankshaft not fitting inside its bearings correctly, or oil quirters in your block clogging is kinda silly. the movement can place excessive or uneven horizontal loads on the thrust bearings, causing premature failures or crank angle sensor failure. Mitsubishi has no recall or TSB regarding this problem.

It appears that Mitsubishi built many 2G engines that have this ailment, 1G owners ( 1990 - 1994) do not generally need to worry, as there aren't as many problems with cranks in those cars. But its possible to get crankwalk in any car. Mazda Miatas, Volga 2.1L engines are a couple of the few other cars known to have issues like this from the factory.

Do I have crankwalk?

You can diagnose whether or not your car has crankwalk by one of the easiest ways, install a dial indicator on the block place the finger of the indicator on the front pully,carefully move the crank back and forth measure the amount of thrust,service limit is .011 or .26mm

What should I do to check or prevent crankwalk?

1. We recommend using a oil filter from a 1g at all times.. A larger oil filter and higher micron will provide for better filtration.
2. 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.
3. 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.
4. one option is building a 6 bolt and swapping it in. Never build a 7 bolt or swap in a reconditioned one.
In some advanced cases, the car will die when making a left hand turn or will be difficult to start.

Here are a few things to consider
1.hardness of the crank
2.depth of hardness
3.method used to harden the crankshaft
4.bearing surface contact width
5.type of material bearing is made of
6.surface finish of the bearing and crankshaft
7.heat VS load and lubrication

"Never build a 7 bolt or swap in a reconditioned one" - I don't agree with this. 7 bolts are a lot more reliable than people think they are. If a car is lightly modded, a 7 bolt swap from another car is the cheapest way to get the car running. In my opinion, it should read "Never build a crankwalked 7 bolt or swap in a reconditioned crankshaft into a 7 bolt engine".

 

[Newlogics]

Actually, that would be hard LEFT turn.

And how exactly left turn would make your clutch pedal go down?
When car is thrown to the left, rotating assembly will be shifted to the right, against the throw-out bearing. It's when hard right turn is made, the rotating assembly is thrown to the left AWAY from throw-out bearing, thus releasing pressure from the clutch pedal. (This isn't a theory by the way, I've dealt with enough CW to confirm this)

 

[keymaster]

Really, if you've dealt with it so much, you'd know full well that taking a hard LEFT turn will make the clutch drop in a crankwalking car. I had crankwalk, I should know. Try listening to the wisemen.

 

[Fastass96]

Yes, hard LEFT turn, not right.

Here's some more crankwalk info...

Title: What is a Crankwalk?
Description: What is a "Crankwalk" or a 'walking' crankshaft? (Is it a crank with greasy hairy legs on crutches?)

A 'crankwalk' or 'walking' crankshaft, occurs when an engine has thrust bearing failure or "blown thrust". It is a common problem with Mitsubishi 2G 4G63 2.0 DOHC (Dual Over head Cam) engines, and we have the solution.

This condition occurs when the the crank suffers excessive movement (crankshaft end play) and causes the crank angle sensor reluctor plate to come into contact with the sensor.

Symptoms associated with the crankwalk:

1. Clutch sensitivity, strange disengage and engage points.
2. Ticking or strange noise from the pulley side of the engine when clutch is depressed.
3. Crank Angle Sensor errors ( check engine light )
4. Difficulty shifting
5. RPMS decreasing significantly when clutch pedal is depressed.
6. Clutch does not return or "sticks" to the floor after being depressed

When this happens the engine will stop running, or you will notice hard shifting, or low clutch pedal. You may also hear a slight ticking noise. There are several theories about crankwalk, however there is no 'rock hard' evidence that officially points out this problem. The movement can be from the crankshaft not fitting inside its bearings correctly, or oil quirters in your block clogging is kinda silly. the movement can place excessive or uneven horizontal loads on the thrust bearings, causing premature failures or crank angle sensor failure. Mitsubishi has no recall or TSB regarding this problem.

It appears that Mitsubishi built many 2G engines that have this ailment, 1G owners ( 1990 - 1994) do not generally need to worry, as there aren't as many problems with cranks in those cars. But its possible to get crankwalk in any car. Mazda Miatas, Volga 2.1L engines are a couple of the few other cars known to have issues like this from the factory.

Do I have crankwalk?

You can diagnose whether or not your car has crankwalk by one of the easiest ways, install a dial indicator on the block place the finger of the indicator on the front pully,carefully move the crank back and forth measure the amount of thrust,service limit is .011 or .26mm

What should I do to check or prevent crankwalk?

1. We recommend using a oil filter from a 1g at all times.. A larger oil filter and higher micron will provide for better filtration.
2. 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.
3. 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.
4. one option is building a 6 bolt and swapping it in. Never build a 7 bolt or swap in a reconditioned one.
In some advanced cases, the car will die when making a left hand turn or will be difficult to start.

Here are a few things to consider
1.hardness of the crank
2.depth of hardness
3.method used to harden the crankshaft
4.bearing surface contact width
5.type of material bearing is made of
6.surface finish of the bearing and crankshaft
7.heat VS load and lubrication

"Never build a 7 bolt or swap in a reconditioned one" - I don't agree with this. 7 bolts are a lot more reliable than people think they are. If a car is lightly modded, a 7 bolt swap from another car is the cheapest way to get the car running. In my opinion, it should read "Never build a crankwalked 7 bolt or swap in a reconditioned crankshaft into a 7 bolt engine".

I have a built 7 bolt with on crankwalk pushing around 700ish. I also can say I have had crankwalk if you replace your clutch make sure to check your stepping height. I have a friend with a chevy 350 that crankwalked.

 

[ineedagsx]

so yea i got crank walk last night (well i have had it but last night everything broke) im starting to pull the engine today but what do i have to do to fix this??? and when i put it back together should i do a balance shaft removale kit? thanx guys

 

[OsOClipsY]

So I was told by a Mistu tech (supposedly a very old and wise Mitsu tech) that 98 and 99 7 bolts have less chance of crankwalk. After hearing this i threw away the idea of getting a 6 bolt engine. Should I be find him and give him a beat down? I didn't question him at the time because he knew "everything"



OsO's so ...

 

[knochgoon24]

It's true that 98 and 99 have had a lower number of reported cases of crankwalk. The crankwalk deal is over-hyped. You'll be fine building your 7-bolt.

 

[bpestilence]

Definately over-hyped. I have seen "thrust bearing failure" in many different kinds of engines, including Chevy and Ford smallblocks.

Why does it happen? For the same reason journal bearing failure occurs. Improper oiling or filtration. Why does it happen more often on 7-bolts? Because there are a whole lot more 7-bolts out there than 6-bolts! And the 6-bolts that many people are using are already built with aftermarket bearings. It's just a matter of probabilities.