Originally posted by CARLiTO_
I dunno what a crankwalk is..can anyone explain? and why would a car be valued less if it has one?

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Hi CARLiTO:


Crankwalk is the result of wear, poor machining, or design of the main bearing responsible for taking crankshaft end thrust. To help you understand the different loads involved a brief detour: for example the belt driven items pull the crank sideways as you tension the belts, the bearings are of course oiled and thus support this sideways pull. The rods push in our case up and down and these loads are again supported by the main bearings. With few exceptions when you attach an output shaft at either end of the crank it will have no effect on the causes of Crankwalk.

Crankwalk is the end play movement (thrust) fore and aft along the line of the crankshaft, it will rarely occur with an automatic transmission if everything is made correctly for they impose no axial thrust. The real problem comes from the forces of pushing on a clutch pedal which is transmitted from the throw-out bearing pushing on the clutch pressure plate to release the clutch disk. The heavier a clutch pressure plate you use the greater the loads are imposed upon the main bearing responsible for taking that axial load. In our case Mitsubishi produced some engines where the machining tolerances were out of specification which caused this bearing and the crankshaft to wear prematurely. In exaggerated cases you can push on the crank of a running engine and see it move 1/4" fore and aft or with a warm engine just grabbing the crank pully and push/pull it will move with a thunk. This puts additional loads on the rod bearings all the way up to the pistons and cause them to distort and wear prematurely.

If this wear is detected while the vehicle is still in warranty nothing to worry about, if out of warranty then it's a very expensive repair $$$-$$$$ which might include replacing the crankshaft, at the very least this thrust bearing will be replaced with a new oversized (width) to compensate for it being out of specifications. The problem here is if the crankshaft is worn greater than the maximum bearing width then the crankshaft will need to be replaced or repaired by welding and machining the worn surfaces. Consider that all the metal worn away went into the engine oil and some was trapped by the filter but some was not and has now been pumped to every moving part of the engine. I've seen this collect in pockets where you have to dig it out with screwdriver for it is quite dense and doesn't wash away with normal solvent and brush degreasing. It means that every part is suspect including the hydraulic lash adjusters.

I'd stay away unless you are in a position to buy right and make all the necessary repairs essentially that of a major engine overhaul and these parts AIN'T cheap new or used.

Cheers,
GTM

i am thinking of buying an automatic talon 97 tsi awd, will it have this crankwalk factor?

Originally posted by CARLiTO_
i am thinking of buying an automatic talon 97 tsi awd, will it have this crankwalk factor?

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I'm not the one to ask since my son has a 1G which were not affected to the degree other generations were having. I believe the information you require exists here on DSMtuners and other DSM sites as well. Use the search engine at the top of the page and it should find a plethora of info on which to base an educated answer to this and other questions you may have. Not meaning to give you the brush off but it would be best if you could feel comfortable searching before asking a question for which may have already been answered 100 times just on this site alone. Some people would have just ignored the question and left you hanging without steering you at least in the right direction.

Using the Internet Google.com search will bring up a wide variety of sources including those from education sites like MIT DSM owners discussions.

Cheers,
GTM