Avoiding crankwalk

[iTurbo]

I have a TIII shortblock I was going to put in my Shelby Lancer. Looked real nice on eBay and it looks almost new...but now that it's on my engine stand I notice that it has almost 1/8" of crankwalk, so it has to be rebuilt.

What causes crankwalk? Does the thrust main bearing wear out normally, or could this be the result of some extreme duty pressure plate being used last time the engine was in service?

I need to get this shortblock rebuilt but would like to know what I can do to prevent this from occuring down the road. I'm hesitant to get go with an aftermarket PP at this point. Is the crankshaft still OK or will it probably need to be replaced now?

[BadAssPerformance]

Crankwalk? not too common in 2.2L... they are not like the DSM motors.

[Pat]

I've pulled apart two motors with destroyed thrust bearings and damaged thrust surfaces on the crank. Both had very heavy pressure plates on them.

[8valves]

My last SB had some pretty obvious wear on the thrust surfaces as well after 1.5 years of a dual diaghaphram PP. That can definately cause issues. It's also one of the failure causes for the "notorious" DSM "problem".

[GLHSKEN]

I've seen it as well caused by a dual TII PP. The dual TBI plate seems much easier on the crank

[8valves]

I've seen it as well caused by a dual TII PP. The dual TBI plate seems much easier on the crank

I'm actually curious how much my endplay had changed from when it was assembled. The bearing showed wear, as in more than what would be expected in that amount of mileage, but it was equal on both sides and wasn't enough to alarm anyone who has seen it. I wonder how long it can go for like that without causing damage.

That would suck if your center main became a "maintenance item" with big PP's. That would be just another reason to chalk up for switching to an auto :p

[tryingbe]

Another reason don't ride on the clutch.

[contraption22]

Crankwalk? not too common in 2.2L... they are not like the DSM motors.

Reminds me of this picture.

[8valves]

Another reason don't ride on the clutch.

I'm fairly certain the folks that have manual tranny cars in need of a DD pressure plate have the driving skill to know not to sit on the pedal... nor the leg strength to do so with those plates!

[Turbodave]

When I rebuilt the 2.5 in my Shadow I went through 3 cranks before I found one that was in spec for the thrust surface, that one was out of a 190K mile automatic car.

I thought it was more of an issue with the cast cranks because I haven't had the problem on any of the forged crank 2.2's I've put together.

[Pat]

I'm fairly certain the folks that have manual tranny cars in need of a DD pressure plate have the driving skill to know not to sit on the pedal... nor the leg strength to do so with those plates!

Amen to that!

Something I did notice...both motors I pulled apart came from guys who ran heavy plates, but also had a tendency to start the car with their foot on the clutch. What I always do (and made damn sure I always did with the heavy plated motor) is always be careful about making sure the car gets started in neutral. I never want to lean on that thrust bearing before there was oil pressure. When my motor came apart for freshening, the thrust bearing was definitely worn and endplay was out of spec, but the motor had 4-5 racing seasons on it with 2 of them with the heavy pressure plate, not to mention countless blasts up the higway testing and a bunch of street miles.

I will say this though...I'm not going the heavy plate route again. Pulling the tranny to replace a clutch is alot easier than pulling the motor to replace the crank. When that gets old, I may go auto.

[GLHSKEN]

I will say this though...I'm not going the heavy plate route again. Pulling the tranny to replace a clutch is alot easier than pulling the motor to replace the crank. When I get old, I may go auto.

Fixed it for ya pat :lol:

[turbovanman²]

Reminds me of this picture.

Hahahhahaa, LMAO.

I too haven't seen any crankwalk issues but as mentioned, HD pp, no service will help kill them.

[TurboGLH]

Reminds me of this picture.

You know what I hate about stuff like that? I have to try and explain to my GF what I'm laughing about. A simple "nothing" won't cut it, but once the word crankshaft leaves my mouth she's completely uninterested.

[BadAssPerformance]

Reminds me of this picture.

Exactly! :thumb:

[Pat]

Fixed it for ya pat :lol:

You're quite the ComediKen!

[csxtra]

You're quite the ComediKen!

Pat,

You know that Adler, he's Kentinuously cracKen the jokes...

[Orangetona]

You know what I hate about stuff like that? I have to try and explain to my GF what I'm laughing about. A simple "nothing" won't cut it, but once the word crankshaft leaves my mouth she's completely uninterested.

LOL... I hear that! Really annoying isnt it?

[GLHNSLHT2]

Just run a plate with the fulcrum points moved instead. Then you get tons of clamping force, an easy Pedal and no undue stress on the thrust bearing. My spec PP has 2600-2800lbs of clamping force but has a lighter pedal than the last Turbo 1 I drove.

[CSXT802]

I've pulled apart two motors with destroyed thrust bearings and damaged thrust surfaces on the crank. Both had very heavy pressure plates on them.

I don't mean to hyjack. Pat was it you that bought my RPS pressure plate.?

[Suder]

Just run a plate with the fulcrum points moved instead. Then you get tons of clamping force, an easy Pedal and no undue stress on the thrust bearing. My spec PP has 2600-2800lbs of clamping force but has a lighter pedal than the last Turbo 1 I drove.

How do you get a plate with different fulcrum points, or how do you get the fulcrum points moved? I'm confused:confused:

[Pat]

I don't mean to hyjack. Pat was it you that bought my RPS pressure plate.?

Yup, but I haven't done anything with it yet.

[Pat]

Pat,

You know that Adler, he's Kentinuously cracKen the jokes...

Especially when he's drinKen!

[CSXT802]

Yup, but I haven't done anything with it yet.

What type of disc are you going to use with it.?

[GLHNSLHT2]

How do you get a plate with different fulcrum points, or how do you get the fulcrum points moved? I'm confused:confused:

You buy it that way.

[Pat]

What type of disc are you going to use with it.?

I'm not sure what I'm going to do with it now...my plans had changed a bit since I bought it from you.

[8valves]

You buy it that way.

LS1 guys complain of increased pedal travel when they try that trick. They have found it makes the pedal release point longer than normal, so modulation becomes a bit more difficult.

Have you found that at all?

[Pat]

LS1 guys complain of increased pedal travel when they try that trick. They have found it makes the pedal release point longer than normal, so modulation becomes a bit more difficult.

Have you found that at all?

I made a longer clutch arm to help with pedal pressure/popping cables with a heavy plate and while it's not an altered fulcrum point, it changes the leverage that effects pedal travel just the same. My experience was that it did increase the range of travel necessary to modulate the clutch, but not in a bad way. It was just different and took a bit of getting used to.

[8valves]

I made a longer clutch arm to help with pedal pressure/popping cables with a heavy plate and while it's not an altered fulcrum point, it changes the leverage that effects pedal travel just the same. My experience was that it did increase the range of travel necessary to modulate the clutch, but not in a bad way. It was just different and took a bit of getting used to.

Perhaps it's not a bad thing then really, for us at least. I know personally that my clutch release point is similar to a feather trigger! There is about a 3/4" range that dicatates on or off, so it is a bit difficult to deal with, but I actually grew to like it.

That should take some stress off of the cable too then! That wouldn't be bad at all. My cable end actually pulled THROUGH the retainer one night. I ended up fabbing up a retainer that is 3X thicker... so that probably means the cable will be done for now.

[Pat]

Perhaps it's not a bad thing then really, for us at least. I know personally that my clutch release point is similar to a feather trigger! There is about a 3/4" range that dicatates on or off, so it is a bit difficult to deal with, but I actually grew to like it.

That should take some stress off of the cable too then! That wouldn't be bad at all. My cable end actually pulled THROUGH the retainer one night. I ended up fabbing up a retainer that is 3X thicker... so that probably means the cable will be done for now.


Mine was the same way with a dual tbi diaphram plate and a 4 puck. Hard to drive, plus, I was popping cables on a fairly regular basis. With the longer clutch arm (don't remember how much longer), I found it easier to modulate the clutch since each inch of pedal travel = less TOB travel. It wasn't as much of an on/off switch. Plus, I calculated the reduction in pedal pressure from the increased arm length to something like 25% less, which was much closer to that of a 1600 lb pressure plate. Never popped a clutch cable again.

[Pat]

http://www.turbo-mopar.com/forums/showthread.php?t=240&page=2

Here's a pic and the specific info on the arm I did.

[8valves]

Very cool, and very simple to make as well. Great idea!

[TurboGLH]

LOL... I hear that! Really annoying isnt it?

Incredibly.




http://www.turbo-mopar.com/forums/sh...p?t=240&page=2

Here's a pic and the specific info on the arm I did.

Great info, should be part of the KC, or at least linked to in the section discussing clutch selection.

[mock_glh]

Perhaps it's not a bad thing then really, for us at least. I know personally that my clutch release point is similar to a feather trigger! There is about a 3/4" range that dicatates on or off, so it is a bit difficult to deal with, but I actually grew to like it.

I've found this to be the best setup for racing, as long as you get full release. It minimizes the shock of engagement and gives the shortest time window when no power is applied to the wheels.:thumb:

[GLHNSLHT2]

The distance from full engagement to no engagement is very short. So yes it's kinda on or off. I like it that way. Also since this distance is short I made a spacer that goes under the clutch pedal stop. This makes the part you step on closer to the floor and also makes the engagement point closer to the floor. I have it setup so that it engages right off the floor. And the pedal is about 1/2-1" lower than the brake pedal. You can really pop off some quick shifts this way. Plus for me it's easier to modulate since you just basically move your toes and the clutch engages or disengages.

It makes it feel and work more like a bottom hinged pedal which is what I learned how to drive a stick with so it's what I like. Wish TD's had bottom hinged pedals.

[Directconnection]

Pat,

You know that Adler, he's Kentinuously cracKen the jokes...

Well, he is from KENtucky ya know.