what ever the feeler gauge says on the front side of the thrust bearing (the side facing the pulleys is what you got if its .018 your done and your cranks probably toast also. Then pull your main girtle off and pull the bearings on only the thrust upper and lower check the crank for grooves if theres not any stick a new thrust in it but before you do that do this to the bearings.[urlhttpwww.4secondsflat.com/Thrust_bearing_failures.html[/url] reed the article and chamfer the bearings like they did. Also if you have to get a crank get rid of the oil squirters like magnus does.

I dug up a photo of someones bottom end and hopefully it is in the correct orientation, not that it much matters, but I'd like to be somewhat accurate.
I believe the right side of the picture is the timing belt side and the left side of the photo is the flywheel side.

The specifics will not alter what I am trying to illustrate.
We measured the gap on the red line and the blue line and then as stated above, derived the "play" in the crank.

I'm sorry but I had a hard time making sense of what "skipdownstairs" was trying to indicate, hopefully this will make it more clear for those of us keeping score at home.

The question remains: Did I measure my crank end play correctly?

EDIT: The gold thingey I drew is supposed to be the splash guard that prevents cavitation and air, rather than oil, getting into the oil pickup.

EDIT II: http://www.hillmanimages.com/912/manual37.html This link seems to indicate I went about this correctly, taking two measurements and and taking the difference, to arrive at actual lateral movement of the crank. But this is hard to directly apply to the 4g63 application because we are also talking about spacers and porches in that link.

EDIT III: http://members.rennlist.com/v1uhoh/cranksha.htm Here is one more Porche reference that corroborates my methods of taking 2 measurements and finding the difference. Where you measure doesn't seem to matter because the crank will only move so much and measuring in different places such as the flywheel will not alter how much the crank is moving.

EDIT IV: http://www.highperformancepontiac.com/tech/0206hpp_racing_reliably_part_i/index.html "..Then a dial indicator is mounted. A large screwdriver placed between the block and a counterweight. First the crank is pushed back and the dial indicator is preloaded and set to "0." Then the crank is pushed forward. The endplay measurement on the gauge is .007, which is within the tolerance range of .006-.011 recommended by Pontiac."
This is starting to sound familiar despite different applications and slightly different methods.

If you could visibly see the crank move from side to side, you are on the way out.

The end-play is the total movement from one direction to the other. The difference between measurements taken at the same point, with the crank moved to either extreme.

An example, we will use your blue line. Pry the crank toward the rear, closing the gap at the blue line as much as possible. Stick (or try to) a feeler to measure the gap (if any). Now, pry the crank toward the front of the engine, to open that same gap. Measure the same gap. (blue) The difference between these two numbers is the total amount of axial play, or crankshaft end-play. If you were to do the same thing I just described on the red line, the first to measures may be different, but the difference between them will be the same.

Another way (the proper way, as mentioned in one of those articles) would be to affix a dial indicator to the block, against crank's snout, and pry the crank away from the indicator. Make sure it is loaded then zero it out and pry the crank toward the indicator. The dial will indicate total axial movement, or end-play.

I hope that make sense.

Talonracn50 said:

If you could visibly see the crank move from side to side, you are on the way out.

Click to expand...

Its fairly easy to see the movement on a fresh rebuild. You really have to measure it to tell whether it's bad unless its way out.

I know crankwalk can happen on any car at pretty much any time but I thought only the 95-96 had the majority of the cw problems is that true?

Locke said:

The end-play is the total movement from one direction to the other. The difference between measurements taken at the same point, with the crank moved to either extreme.

An example, we will use your blue line. Pry the crank toward the rear, closing the gap at the blue line as much as possible. Stick (or try to) a feeler to measure the gap (if any). Now, pry the crank toward the front of the engine, to open that same gap. Measure the same gap. (blue) The difference between these two numbers is the total amount of axial play, or crankshaft end-play. If you were to do the same thing I just described on the red line, the first to measures may be different, but the difference between them will be the same.

Another way (the proper way, as mentioned in one of those articles) would be to affix a dial indicator to the block, against crank's snout, and pry the crank away from the indicator. Make sure it is loaded then zero it out and pry the crank toward the indicator. The dial will indicate total axial movement, or end-play.

I hope that make sense.

Click to expand...

Makes perfect sense. But what you described is just another variation of what I performed on my car and what those links seem to indicate.
Would you agree, thus making my measurements correct?

stomp said:

I know crankwalk can happen on any car at pretty much any time but I thought only the 95-96 had the majority of the cw problems is that true?

Click to expand...

True.
The 97's have gotten a bad rap for CW also though since the revised "split" thrust bearings were introduced in 1998. They are a 3 piece design that increases oil flow and surface area.

PieEyedPiper said:

Makes perfect sense. But what you described is just another variation of what I performed on my car and what those links seem to indicate.
Would you agree, thus making my measurements correct?

Click to expand...

If I am interpreting your test procedure correctly, then no.

As your method appears to me, you are not accounting for variances between the closed gaps at the different thrust surfaces. Measuring at multiple points, if accounting for variances, would be redundant, and would prove the same outcome as measuring at one. You would need to make both measurements at the same thrust surface to get a measure for axial play.

I'm with Locke. I'd measure the change in gap at either the Red or Blue shaded areas with the crank pressed to the limits of each lateral end.

Note since you are measuring the crank lateral movement, performing the above on either the Red or Blue lines should return the same result (as would simply measuring off the crankshaft's snout)

DSM90AWD said:

I'm with Locke. I'd measure the change in gap at either the Red or Blue shaded areas with the crank pressed to the limits of each lateral end.

Note since you are measuring the crank lateral movement, performing the above on either the Red or Blue lines should return the same result (as would simply measuring off the crankshaft's snout)

Click to expand...

Huh. I wonder why I can't simplify things like that. Thanks, John.

Ok, for a while I was convinced my method was as good as any but I realize now, after being unable to produce reliable results in autocad (I had to visualize it to fully see if my method worked), I've decided to stop wondering and hurting my brain by over thinking it and I'll just take it back to my mech and we'll use a dial indicator on the crank from the crank pulley side.

Thanks you guys, I'll update when I can.

I've always thought the measurement range for crankwalk was a bit strange. The safe limit of crank endplay is in thousandths of an inch if I remember correctly, yet every time I've heard of a motor crankwalking, you can visually see the crank move in and out when you use a prybar.

When I was pretty sure my 6 bolt 2.3 was walking, (YES, 6 bolt..) I took it to my mechanic to measure the endplay. He's kinda a more oldschool guy with his techniques but I have NEVER had a problem with any of his work, and he does great work. He mostly does DSMs and has several himself. He jacked my car up and pried the crank pulley back and forth and it moved what looked like almost a 1/4 of an inch, at least 1/8 of an inch. I've heard from several other people that they noticed the same thing when theirs walked. Luckily mine turned otu to be a bad crank, and with a new one everything's perfect.

There are obviously degrees of "walking". Most of the the cases you hear about are those extremem instances in which the person was unaware of the sympoms/causality and waited until the thrust bearing was completely gone before acting. At this point the crank endplay is well outside the tolerances since the bearing is near gone which has also likely caused damage to the crank itself

I recently came across a thread regarding a groove in a timing belt being worn from putting the wrong oil pan bolts in the wrong places. What a horrible way to be forced into doing a timing job.
I was not aware of this issue when I removed my pan, as described in the first post. So of course the short bolts were installed in the wrong spots putting the longer bolts in a position to damage my timing belt.
I removed the timing cover today in the campus parking garage to discover faint marks being scribed onto the outside layer of the belt. Lucky for me I'd only been driving with it for a couple weeks, if-even. I went back to the shop and described my woes to my mechanic. I love using his equipment! i.e. The lift. We simply removed the longer bolts and cut them down to size and replaced them.

Disaster adverted.





But the real good news is that I also asked my mechanic about our method of measuring crank endplay. We measured correctly.
I misinterpreted what I saw take place during the process. When he was measuring the bearing gaps at either end of the colored lines in the diagram above he was simply checking them out and went on to measure the red line in the diagram twice at both polar (can I really even use this word here?) extremes of the cranks lateral movement. As further illustrated, and most importantly, clarified by the Wisemen above.

Verdict? I don't miss the enormous dread saturating my chest cavity that accompanies the thought of getting a loan or other means to get the money for a 6 bolt swap. But I was researching about building a 6 bolt and quite enjoying it. I think I could handle it, but again money is a major factor considering all the tools and materials I would require. But who knows? Maybe its just the best excuse to buy a nice engine stand