***Crankwalk...Please Read***

[RamenPride]

Originally posted by sophat34
magnus's theory is that the oil squirters get cloged in the open position. there always leaking or squirting oil. they were designed to close at a certian oil pressure so that the rest of the oiling system would get more oil.

the theory is that the squirters get clogged and stick open. at idle, oil is squirting through them, when there really doesn't need to be any oil going through them to cool down the piston. as a result, the rest of the system loses pressure. you step on the clutch and there is a very miniscule, if not absent, film of oil on the thrust bearing. the crank starts wearing away at it slowly but surely, until it starts moving laterally.

 

[RedBird]

Since so many people who don't know anything about cars ask about crankwalk, and me being a mechanic , I'll give the newbies a little breakdown. Anytime your engine is running the crankshaft is rotating. There are main journals of the crankshaft which "roll" on thrust bearings in the block. Now with the oil theory it is a definite possiblility and I would almost back Magnus 100% on this because when the engine is running you have oil pressure from the pump. Small holes drilled through the crank allow oil to pass through it between the bearings and the crank, so technically your crank and thrust bearings should never contact, except on startup when you have no oil pressure. So keeping good clean oil in your engine is very important. One suggestion I have for those of you willing to go far enough, you could wire new ignition and starter switches on your car, allowing you to bring up oil pressure on your car before starting(disable ignition, turn over the starter). This is done on nearly ALL race cars. What does this do? It allows you to have significant oil pressure before firing the engine resulting in minimal metal to metal contact virtually eliminating wear of parts.

Now as for the clutch theory, its possible but not likely in my opinion. (Again this is for newbies) Everytime you let out on your clutch pedal the pressure plate behind your clutch is "releasing" and putting pressure on the clutch to clamp it against the flywheel which is bolted to the end of your crankshaft. Keep in mind the crankshaft is designed to rotate NOT slide horizontally in your engine, but everytime you release your clutch there is a fair amount of pressure pushing the crankshaft toward the pulley side of your engine. Therefore wear of the bearings could occur IF there is not significant oil pressure.

There are other possibilities though. Improperly machined cranks/thrust bearings. The thrust bearings used on the 2g's is actually a 2 piece unit unlike 1g's. Anytime you have more parts you have more room for error.
Hope this answers some questions and sheds some light. For any of you who have not read Magnus's page on crankwalk you should, its very ineresting. www.magnusmotorsports.com
Feel free to e-mail me with any questions, I'll be glad to help anyone. If anyone notices any errors here feel free to correct me.
Brian
[email protected]

 

[Kevin Jewer]

Well the main roblem is thrust bearing design. And this aplies to all cars. The main bearings, rod bearings, cam bearings, etc are all round. The part that is rotating moves within the oil clearance specs, to one side of the bearning. An oil "wedge" is created. That is what seperates the part. With a thrust bearing, there is no way to build an oil wedge because the bearing is two flat surfaces sliding on each other. No rotation, but sliding. So all you can do is pray that there is enough oil flow ot the bearing to keep a light film of oil there to reduce friction, but it cant relaly seperate hte two parts. There are all kinds of tricks to get more oil in there, like filing the edges of the bearings. The bottom line is on any car the thrust bearing is a pain in the ass. Add high pressure clutches, high stall torque converters, etc and its easy to excede the thrust load capacity o the bearing....

 

[91TSi FWD]

Update.

Crankwalk...

Crankwalk reffers to a crankshaft which moves an excessive amount inside the engine.

Many 2G owners have experienced ‘walking’ crankshafts. This happens because the crankshaft does not fit in the bearings proporly. Crankwalk is also known as thrust bearing failure. the bearing fails and allows the crank to "walk". A walking crankshaft will not harm the crankshaft itself, but the movement can place excessive or uneven loads on the bearings, causing premature failiure.

When the crankshaft "walks", it pushes the backplate into the crank angle sensor causing it to fail (literally, it tears through the crankshaft angle sensor). Once the sensor fails the viechle will not start. This problem usually manifests itself as a ticking noise coming from the timing belt area, as the sensor is literally and slowly ground away by the crankshaft. Any such noise should be investigated right away to prevent serious problems. If you have taken apart your car to replace the crank sensor, look to see if there are plastic shavings on the trigger plate, where the plate has actually contacted the sensor itself. If your crank sensor has suddenly failed, the chances that the sensor has done so on its own are low. To replace the sensor alone is a short term fix, if your crankshaft is walking. Getting to the crank sensor is a lengthy process since the timing belt and all else has to come off.

Other causes of crankwalk include the 2g oil injectors(AKA-oil squirters). The theory is that the squirters get clogged and stick open. at idle, oil is squirting through them, when there really doesn't need to be any oil going through them to cool down the piston. as a result, the rest of the system loses pressure. you step on the clutch and there is a very miniscule, if not absent, film of oil on the thrust bearing. The crank starts wearing away at it slowly but surely, until it starts to warp the bearing and literly start moving. Also, it has been stated that a higher pressure clutch application, especialy the 2600, accelerates the process if you are going to get it. However, let it be known that there is no solid proof as of yet that a strong pressure plate causes crankwalk because of the relatively common occurence in stock cars.

The crankshafts in many of the 1G DSM’s have a different crank and bearing design than the later 7-bolt engines. The six-bolt motors are not nearly as suseptable to get crankwalk as the later 7-bolts. The 6-bolt engines were produced between March, 1989 and the third week of May, 1992. May 1992 to the first week of May, 1994 have 7-bolt motors in the 1G DSM’s. All 2G DSM’s have the 7-bolt engine. Even though the Spyder has a 2.4L SOHC engine it can still crankwalk, as with the 1.8L 1G. Note that any engine can get crankwalk, even big V8’s.

If you want a temporary fix for crankwalk, you can contact Mitsubishi as they have made bearings which propory fit the crankshft. Matching the bearings is tricky and requires exact information about when the crankshaft was manufactured, which may be determined by color markings on the crankshaft itself. The 2G factory manual includes information on how to match crankshafts to bearings.

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.

Also, there is no recall as of yet on the crankshafts.

for more info on crankwalk, check out these sites.
- http://www.magnusmotorsports.com/crankwalktheory.htm
- http://members.shaw.ca/costall/1000Q/
- http://www.vfaq.com
- http://www.nx2k.com/eclipse/crank_walk.htm
- www.magnusmotorsports.com
Or go somewhere like google and do a search for crankwalk.

 

[91TSi FWD]

Anyone else have something they would like to add??

 

[autoxcrazy]

I have a 93 tsi, I had a centerforce clutch in it and had to take it out because it started walking the crank, almost every hard left turn would leave the cluch on the floor, but I went back to a stock clutch for now and have had it only happen a few times I know its time to get a six bolt soon.

 

[autoxcrazy]

oh yeah I put that clutch in at like 80 to 90k and blew up a tranny and now I am at 125k

 

[Kevin Jewer]

Just to illustrate that it can be the oppostite of your case, of the three 95 motors that CWed on me, the first two went at 30k miles and 40k miles, and the one with the ACT 2600 lasted 50k. It was going strong too, until I dented the oil pan and it CWed that night Just my expereinces anyway.

 

[91TSi FWD]

Bump

Anyone else want to add anything?

 

[FyxxterZC]

I wouldn't mind adding some crazy afterthoughts that I lately have been having. I'm no scientist nor am I an engineer. But has anybody thought that perhaps it's the metallurgic content of the engines that has caused this? I remember reading something about old chevy corvettes getting this because the blocks were "pickled" rather than left to sit and cool down. It said something about cutting down on production times but also said that the blocks core shifted. Maybe the content of the 7 bolts are a little softer than the 6's or am I just being moronic? I also remember reading about the old 2.3 ford turbo engines that had more nickel than the other blocks at that time. You all have surely heard those blocks can take 30 psi with maybe just a few hundred head gaskets being popped? I'm no expert at any of these ideas but are there any chemists out there who can break down a 7 bolt to that level? So far I'm on 99k miles on my otherwise stock 95 gst and no crankwalk with a 1/95 build date. Starting to hear things I don't like though. I'd still like to see a definative answer as to what causes it to happen.

 

[TSi999]

Originally posted by Enraged78


Congratulations, you have one of the "Early Build" '95's. The early build '95's are arguably one of the rarest DSMs. These were the first 2G DSMs off of the assembly line, and oddly enough, every one I have seen so far has been a Talon.very wierd code in it. CEL's seem to go off very easy in the early build's.

Matt.

very interesting Enraged thanks for the info. Mine is a 5/94 build no vented rears I wonder how long would be considered the 'early" cars.

 

[Phoenix_RsX]

I am yet another victim......my car has been ticking from the timing belt area, not to mention I've been having a hell of a hard time shifting into third.

 

[91TSi FWD]

Originally posted by 91TSi FWD

When the crankshaft "walks", it pushes the backplate into the crank sensor causing it to fail (literally, it tears through the crankshaft angle sensor). This problem usually manifests itself as a ticking noise coming from the timing belt area, as the sensor is literally and slowly ground away by the crankshaft.

Just to clear something up, the ticking noise coming from the timing belt area could also be a common case of lifter tick, take a stethescope to the valve cover, and that should be where the noise is coming from if its just lifter tick. Lifter tick will be more noticable on startup when the engine is cold.

 

[LightningGSX]

I've never seen a CW'd engine but isn't it the thrust bearings that fail and not the block or the crank?So the metalurgy of the crank/block would be meaningless.

 

[DSMJim]

Another thing to add is, don't think you don't have crankwalk because you don't have any of the problems listed as symptoms. Far too often I see people saying "No signs of crankwalk here" yet they have never actually measured the endplay of the crank and have no idea if they have crankwalk or not. They say no signs because it makes them feel better thinking they are one of the guys who will "NEVER" get crankwalk, thats for other guys on message boards I dont know.

Just because your clutch doesn't stick to the floor around left turns doesn't mean you don't have crankwalk. You very well might have it and don't even know it. However, Ignorance is bliss most of the time and if you can't afford to fix it, don't try and diaganose it either.

 

[FyxxterZC]

So far no mine doesn't have it this I know. I've had it checked out and it's within spec. As for the block being the cause of the crankwalk, there could be core shifts in the block itself with no signs of anything being wrong. I doubt this is the problem though. To me it looks more like it could be a bearing to crank match problem or hell I dunno. It just seems there's something we're all missing. Hard to explain why some can go for 100 k plus and others go out at 30k. It might just have to do with how high or low of a pressure plate you have. Just my curiousity getting the best of me I guess. 100100 and climbing.

 

[zerofreez]

163,000 beaten on miles.
ACT 2600

NO CW

 

[Maximuscr31]

78,000 miles no cw....

Act 2600 w/ fidanza flywheel

 

[my95tsi]

Yeah my car was built in 3/94 also. I've had no bad luck with it yet. Everything is working just as good as the day i got it. But with the vented rear brake issue, that would explain why i couldn't get the right pads from napa b/c they said they were pads made for the 2g but they wouldn't fit and they didn't look like the stock ones.

Originally posted by Enraged78


Congratulations, you have one of the "Early Build" '95's. The early build '95's are arguably one of the rarest DSMs. These were the first 2G DSMs off of the assembly line, and oddly enough, every one I have seen so far has been a Talon. I have an early build '95 (built in the beginning of 3/94, and have been told that it was one of the first 2G's EVER off of the assembly line. Some wierd things you should know: First, you have vented rear brakes. No other stock 2G's do. Second, if you have ABS, it is different than any other ABS produced. To be honest, early '95 ABS was probably the worst. Third: Early build '95's seem to have the lowest risk of crankwalk of any 2G, save the '99's. Fourth: I have been told that the early build '95's were more of a 1G/2G hybrid. The more I work with the car, the more I see it. You still have the crappy T-25 and plastic BOV (unless you've changed it), but you will start to notice 'little things' the more you work with the car. Fifth: You are guaranteed and EEPROM ECU with some very wierd code in it. CEL's seem to go off very easy in the early build's.

Matt.

 

[Generation X]

Well... I just had some acc. belts installed on my car at the dealership the other day, I usually do my own maintenance stuff, but lately I have been so busy from working that I decided to let the dealership do the belts. I asked the service manager if they could also check the end play on my crank. When I came to pick up my car the service manager actually let me talk to the mechanic who worked on my car, and he told me I had about an 1/8 of an inch of end play, which he then said is way out of spec, now mind you I have no sticking clutch, no ticking, but my car sometimes, and only sometimes is a little difficult to put into 1st gear, the rest of my gear changes are like butter. My car also has 77,000 miles on it and I change the oil every 2000 miles. I'm not sure, but to me an 1/8 of an inch is alot to me, I'm not to sure what amount of play is within spec, but with that amount of play it seems like my car should be all to hell, but it runs fine, and I usually only drive it on the weekends. I have had this car for 4.5 years and babied the hell out of it. So... I don't know if this mechanic is bull-shitting me or not. He also told me that to get a more accurate reading he would have to drop the oil pan to check out my thrust bearings. I don't know what I'm going to do now. I went through this same type of crap with my old RX-7's except it was the apex seals.

 

[talongod]

My door sticker says 4/94 but its a 95 tsi i have over 120k miles on my car and the clutch started acting up and my car stalled out and wont start up im getting no spark and i took it to my mechanic and he said its a crank shaft sensor HELP do u think this is CW? what should i do?

 

[DSMJim]

Originally posted by Generation X
Well... I just had some acc. belts installed on my car at the dealership the other day, I usually do my own maintenance stuff, but lately I have been so busy from working that I decided to let the dealership do the belts. I asked the service manager if they could also check the end play on my crank. When I came to pick up my car the service manager actually let me talk to the mechanic who worked on my car, and he told me I had about an 1/8 of an inch of end play, which he then said is way out of spec, now mind you I have no sticking clutch, no ticking, but my car sometimes, and only sometimes is a little difficult to put into 1st gear, the rest of my gear changes are like butter. My car also has 77,000 miles on it and I change the oil every 2000 miles. I'm not sure, but to me an 1/8 of an inch is alot to me, I'm not to sure what amount of play is within spec, but with that amount of play it seems like my car should be all to hell, but it runs fine, and I usually only drive it on the weekends. I have had this car for 4.5 years and babied the hell out of it. So... I don't know if this mechanic is bull-shitting me or not. He also told me that to get a more accurate reading he would have to drop the oil pan to check out my thrust bearings. I don't know what I'm going to do now. I went through this same type of crap with my old RX-7's except it was the apex seals.

If he knows enough to say he needs to drop the pan to get an accurate reading then chances are he knows what hes talking about. 1/8 of an inch is a lot. WHen it moves far enough it will start coming into contact with your CAS and thats when the tick of death starts. It's then you will know for sure you have crankwalk.

Your car has crankwalk now with that much movement however it's just not touch the cas yes. Start looking for a 6 bolt my friend.

 

[2GeNTSi]

I'm not sure when my 95 was built but when I went to Chrysler to get something checked out they looked on my door jam and the guy said "So this is a 94?" and I never looked there so I didn't know what he was talking about. Are all early 2gs built in 94?

 

[Generation X]

Originally posted by DSMJim


If he knows enough to say he needs to drop the pan to get an accurate reading then chances are he knows what hes talking about. 1/8 of an inch is a lot. WHen it moves far enough it will start coming into contact with your CAS and thats when the tick of death starts. It's then you will know for sure you have crankwalk.

Your car has crankwalk now with that much movement however it's just not touch the cas yes. Start looking for a 6 bolt my friend.

Yeah... that's what I figured. If I could only find someone in my area which is Asheville, NC, or somewhere close to Charlotte, or even Greenville SC to do a 6 bolt swap for me I would be a little happier, but where I live theres not to many people, or good quality shops around that will do the swap for me. I asked the mechanic at the dealership about it and he said that they didn't get involved with stuff like that. So... I'm stuck until I find someone to do it for me, or I could get another 7 bolt which I will not, unless it's an EVO III 7 bolt.

 

[FyxxterZC]

I live down the mountain in morganton, nc. I might know a guy who could put it in. Might take him some time but he's worked on dsm's before. I bought my 92 talon from him. Or if you've got a garage I'll help you out whenever you need it during the weekends. I'll also help to put the six bolt in. email me if you want we'll chat more about it. my email is [email protected] if it's not listed in my profile.