Such as?^^ +1 and alot of it depends not only on the car's setup, but the drivers habits as well.
such as not doing the clutch switch bypass and constantly pushing the clutch in on cold startups. Also, some people love to sit at stoplights with their clutch pedal in, which doesn't help since oil pressure while there, is relatively low in most cases. I had the HPF feramic clutch with ACT pp and mine crankwalked.... while I did not have the clutch bypass done, I did not do anything out of the ordinary that i believe would have contributed to my crankwalk. Here is a pic of my thrust bearing that got wedged between the crank and #4 main cap.Such as?
I've got an ACT PP with HPF disk. Is there really any connection between crank walk and single disk clutches, or just the usual internal BS that gets blown out of proportion?
Ck,That is unfortunate.
I'm trying to learn more about what causes CW, as well as what prevents it effectively. I'm willing to buy a twin-disk, but before I spend $2500 I want to know that is actually the solution to the problem. I'm wondering if the switch bypass and an Accusump would solve the problem?
My engine drops about 200 RPMs from 900 to about 700. I was told this was normal, but seems to me that I was lied to and my crank is starting to walk. What can I do (short of pulling out the engine) to check for crankwalk. Doesn't help that I JUST finished getting my brand new ACT HD PP with 6 puck in also.OK. I would like to do a short summary for those of you who are asking how to tell for signs of crank walk.
Extremely small crank walk WILL NOT be noticeable.
Moderate crank walk can be found by:
1. Observing the Harmonic Balancer when the engine is idling. Have someone push in the clutch and observe any forward or back movement (thrust). Any movement forward or back is respective to the type of clutch on the car (push or pull type). If it's an automatic, you can put the car in drive, hold the brakes, and rev it to stall speed. If any visible thrust is present, the crank is walking. Do the same procedure with the engine off, transmission in neutral. This is why I say that minor crank walk will not be noticeable. Nobody can see .005" of thrust with their eyes.
2. Once the vehicle has warmed up, push the clutch in while idling. If the engine drops in RPM, begins to stumble, or sound like it's working harder, the crank is walking.
3. With the engine idling, lightly depress the clutch. Do not fully depress it. Just when it begins to engage, feel for any awkward vibration or pulsation. If you feel some, more than likely the crank is walking. This in some cases can be confused with a bad throwout bearing.
Heavy crank walk will produce:
1. Extreme load when clutch is depressed, resulting in severe drop in RPM or engine stall.
2. Major pedal pulsation while engaging clutch
3. Metallic oil
4. Very visible harmonic balancer thrust either forward or backwards. (again, push or pull type clutch)
It is worth noting that even moderate crank walk can result in catastrophic engine failure. At this point, the engine should be thoroughly inspected.
What is happening ECACTLY? Well, in short summary, the engine is wearing itself to death. Engine internals are not meant to experience much lateral thrust. A tiny bit (.005) is normal, however once the thrust washers wear to the limit, the connecting rods begin to "bind" by going up and down at an unintended angle. This causes wear to the face of the connecting rod and crank journal. The crank will also wear at the main journals. (see page one for pictures of the main cap worn entirely) Rod bearings will wear to one side or the other, with respect to the direction of the thrust. At this point, the engine has begun to wear catastrophically. Eventually the thrust washers will have worn so thin that they will fall right out of their positions on the face of the main and cap. Once this happens, the crank will walk forward and backward only to the limit of the angle the connecting rods can sustain before they either fail, or the engine stalls. When this happens, like it did in my case, absolutely NOTHING in the block is reusable. The walk was so bad, the timing reluctor (or timing pulley attached to the crank as most call it) was wearing into the face of the oil pump. Furthermore, if you look at page one, you can see a pile of bent thrust washers sitting in a pile. While making the last drive home before the engine failed, I actually heard one of the thrust washers fall out of its' slot and get thrown around in the engine by the crank. It was a very faint pinging that lasted for about 3 seconds. That explains why it twisted and contorted.
I hope this helps all of you. Bypass that clutch switch!!
Have someone press the clutch while you're looking at the crank pulley. If movement is visible,drop lower oil pan , most likely thrust washers are worn down and halfway out.If you haven't had FMS leak yet , it's bound to happen any time.20k miles on brand new Toyota short block with stock clutch, 4k on ACT yellow PP,cranking car up ,sitting at the light with clutch pushed in killed my thrust washers ,took a chunk of piston on it's way out.My engine drops about 200 RPMs from 900 to about 700. I was told this was normal, but seems to me that I was lied to and my crank is starting to walk. What can I do (short of pulling out the engine) to check for crankwalk. Doesn't help that I JUST finished getting my brand new ACT HD PP with 6 puck in also.
Alright will do thanks for the info, do I have to replace more than the Front main seal and thrust washers also? I'm planning on just changing everything out just to be safe, but a short block is a bit much.Have someone press the clutch while you're looking at the crank pulley. If movement is visible,drop lower oil pan , most likely thrust washers are worn down and halfway out.If you haven't had FMS leak yet , it's bound to happen any time.20k miles on brand new Toyota short block with stock clutch, 4k on ACT yellow PP,cranking car up ,sitting at the light with clutch pushed in killed my thrust washers ,took a chunk of piston on it's way out.