Jafro's crankwalked 7-bolt [1080 HD] Merry X-mas!

[Jafro]

No worries! I've got it all covered. 'been sitting on a spare 6-bolt for 6 years just in case this ever happened. It's a blessing in disguise.

Many of you have seen my videos. I post a ridiculous number of videos about the DSMs I love breaking so much. I wanted to post what my crankwalked 7-bolt teardown looked like. I'm posting it here for those searching for "Crankwalk" here on DSMtuners that are new to the community (or those who haven't subscribed to my channel yet... hint hint ).

This video illustrates what the failure looks like.

CRANKWALKED! 7-bolt teardown 1080HD - YouTube

I just finished a separate 8-part series on shortblock blueprinting techniques if you want to know what a good engine looks like (the shortblock that will be going back in it). They can be found on my YouTube uploads if you're interested.

I hope Santa brings ALL OF YOU lots of loot!

 

[Pwrtrip75]

So what was the thrust clearance? I couldnt read where the decimal was it was too small.

And damn you work fast... 6 pack of energy drink or what?

 

[volkerding95GSX]

His channel is AWESOME everyone should go check it out if they haven't yet, and subscribe!

 

[GsXdSmKingGsX]

You and jjrock are the only ones that consitantly post helpful videos.. Major props to you amigo.

 

[Colt90tsi]

Good video!! Man it must be nice using air tools!!

 

[Rsawd95dsm]

i agree about the posting of useful videos

 

[954TalonTsi]

Love the hard earned plate of cookies at the end . Nice video as usual

 

[JusMX141]

Only .012-.015" out? Throw a set of main bearings in that bi*** and keep her rollin'.

 

[2slow4now]

I just love videos that actually show what is going on like this! My boys aren't apt to be mechanically inclined, uninterested, and the attention span runs a little short so this is perfect for them to watch and learn some. Learning in FFWD! Great video! Its a little more exciting than watching dad go to the tool box, get a beer, and wrench away.

 

[bradikus7]

Love your videos Jafro! I've watched pretty much all of them. So in your comments on this video you claim the crankwalk was because of a missing tranny bolt? I assume your talking to the small one from the tcase side right?

Also if that was missing from a previous owner did you build the motor in the first place or was that how you got it? Just curious! Can't wait til the next installment.

 

[ed1380]

Only .012-.015" out? Throw a set of main bearings in that bi*** and keep her rollin'.

It also looked like spun rod bearings on 3 and 4

 

[4CEDinduction]

awesome video

 

[josh1095]

amazing video! thank you so much. my mechanic is taking so damn long im going to forward him this link

 

[Kalub]

I love Jafro's vids. I've seen them all countless times, and they all help so much!

 

[SlowChild3]

Your videos rock!

 

[Tigerhorns]

I watch the shit out of your videos. Your the DSM video man!!!

 

[4Lurker4]

Keep all these videos coming, haven't missed one yet and subscribed . Very valuable asset to tuners on this board, happy holidays Jafro!

 

[TrevStarr]

Love the vids jafro!! Been watchin and keeping up for better part of a year now. Thanks for the time and effort

Trevor

 

[boredog]

Thank you for all the great videos that you make. Keep up the good work and good luck with the build!

 

[99gst214]

Great video(s)! I too am a Redskins fan!

 

[jakelandry]

Just figured id contribute my thanks also jafro.

 

[Turbotsiawd]

Great video thank you

 

[Jafro]

No, I thank all of YOU. It takes an enthusiast to keep a DSM running nowadays, and you're all doing what I love. Each and every one of you in your own way. If that weren't so, what are you doing here in a DSM forum?

It's mitsubishi enthusiasts who taught me everything I know. What I missed, I made up for with breaking stuff. I'm still breaking stuff. I don't know everything. I thought crankwalk was a myth until I experienced it for myself... but what I've learned is it's a symptom. It's not the problem. There are a lot of different problems a DSM can endure that will lead to this kind of failure, but the problem isn't itself–this failure.

I just love videos that actually show what is going on like this! My boys aren't apt to be mechanically inclined, uninterested, and the attention span runs a little short so this is perfect for them to watch and learn some. Learning in FFWD! Great video! Its a little more exciting than watching dad go to the tool box, get a beer, and wrench away.

That's pretty much why I use this style of video to deliver the mechanical message. Everyone already knows how their tools work. The video's just slow enough to witness that I used the tool. The reason why I do this is because I've always been ADD as a mofe, but nobody knew ADD was until I was in my mid-20's. It's not a curse. A short attention span seems problematic to some, but it's really been nothing but a blessing to me. It allows me a more efficient means of multi-tasking. I've been able to learn much more if placed in front of a hyperactive-friendly media for learning. So I deliver in the format which I'd learn best FROM. Basically I'm catering to myself.

"Normal people" don't seem to mind it either. They also know how their tools work as well. They appreciate the time it saved them, while the ADD people are like, "cool, thanks for doing that at my speed".

It always bugged the crap out of me the scenes that were skipped in the Sunday PowerBlock shows while it gets filled with endorsements or fluff that takes attention off the project. Shows like Trucks and 2-guys garage, or Monster Garage, OCC, etc... I wanted to see the whole job start to finish, "but let's first check to see what came in the mail"... and then a "While we were gone, xxxxx is finished with installing the subframe, suspension, engine, transmission, axles, and now let me just screw on this fancy center cap I got in the mail and put it on the dyno to see what she does!". Find me a gearhead that doesn't feel that way about those shows. Show the whole damn project already.

Love your videos Jafro! I've watched pretty much all of them. So in your comments on this video you claim the crankwalk was because of a missing tranny bolt? I assume your talking to the small one from the tcase side right?

Also if that was missing from a previous owner did you build the motor in the first place or was that how you got it? Just curious! Can't wait til the next installment.

In late 2000, I bought this car with a busted second gear and 108,000 miles. It had a cheap aftermarket clutch in it. So, somebody had been inside it before I bought it. I paid someone to put a TRE stage 3 transmission with an ACT2600 in it to solve its original problem. That transmission lasted 11,000 miles and failed with the same problem. I took that opportunity to build the engine, grill my transmission builder like a fool... but ended up pretty much buying another one of the same thing. The next transmission went 7000 before shredding a shift fork on second. Rebuilt it with another huge round of mods insisting I end up with a bulletproof trans. 28,000 miles later I shattered 4th sending a piece of it through the case. Replaced it with a new TRE stage III... the one I have now.

We're looking at $10,000 worth of drivetrain problems before having to face what's in this video. Crankwalk isn't the biggest thing to fear on a DSM by any measure. It's what can go wrong if you don't have your drivetrain straight. I'm not going to tell my whole history in this, that's just what's pertinent to my upcoming point.

I had read everything there was to read. I had talked to everyone about my issues and none of it made any sense. I had done everything right. It's not what I was doing right that was the problem, it's what I didn't know I was doing wrong.

I mentioned the crankwalk bolt. That's what I will forever call it. There's ONE BOLT that wasn't on my car when I got it. The mechanic I paid to swap the first trans didn't encounter it, so it didn't get put back in. I did the next 3 swaps, and I didn't manage to fix this problem until the latest build, because I didn't know about it. It's covered well in my transmission video. It is indeed the M8x1.25x60 bolt that attaches the rear corner of the block to the transmission on the transfer case side. It didn't matter that I had corrected the problem, the damage was done already to the rotating assembly.

The reason I fragged my 6-puck clutch is because the clutch wasn't disengaging evenly. If you leave that bolt out (or in my case, never had it), then the pressure applied and removed every time you mash the clutch eventually loosens the bell housing bolts and causes the clutch to disengage unevenly. The result is insane clutch chatter, and LATERAL FORCES APPLIED TO THE CRANKSHAFT THROUGH THE FLYWHEEL. Essentially it bends the crank. If pressure isn't applied evenly around the face of the flywheel, then those forces are transferred directly and unevenly to the main thrust bearing.

Almost every case of crankwalk I've heard about occurred after the first clutch was replaced. I won't venture to claim that this bolt is the cause of every case of crankwalk, but I wonder how many other people have suffered this fate because the mechanic doing the clutch job forgot it or left it out? It's a smaller diameter than the rest of the bolts. It's not in an intuitive location. There aren't huge red flag warnings all over discussion boards about it leading to crankwalk, but there is info about people having problems taking their transmission out because of it.

There are theories about startup oil pressure, oil squirter failures, massive clutch pressure plates, clutch pedal campers, swiss cheese bearings, block casting defects, oil quality, clutch adjustment, etc... all leading to crankwalk. Well guess what? All those things can lead to crankwalk. Crankwalk is merely a symptom of the real problem, much like addiction is a sign of deeper rooted psychological problem in a human. Crankwalk is how your engine deals with the real problem. It walks.

Had I put that bolt back in 48,000 miles ago... I have NO DOUBTS that I'd probably be on only my second transmission, and that it would still have been in perfect mechanical order with in-spec thrust clearance. Evidence of this is in the video, as I rotated the crank and checked the thrust clearance, I got different high and low values indicating my crankshaft was bent. Only one thing is going to bend a crankshaft like that, and it has flywheel bolts going through it. The rod journals are smaller than the mains, therefore they become the focal point of the lateral forces. There's no thrust bearing on mains #4 and #5, so the full force of the clutch pressure lands on rod journals #3 and #4. It will create harmonic vibrations as the rod journal passes under and away from the pressure point on the flywheel. Those forces would create vibrations that are transferred DIRECTLY to the thrust bearing, wearing it out prematurely. So you see, crankwalk wasn't the problem in my case. It was the result. It actually could have been avoided.

Amazingly, all 4 wrist pins are in flawless condition and the pistons aren't even cracked. The mains bearings are in fairly good shape with the exception of #3. The thrust bearing and crank are totalled along with #3 and #4 rod bearings... but #1 & 2 on the other side of the thrust bearing are in flawless condition. I'd say that this particular type of crankwalk failure can ONLY be caused by a mis-aligned transmission.

Perhaps denial prevented me from going through the rotating assembly when I replaced that clutch? Either way I was waxing Corvettes and Shelby GT-500's with consistency all the way to the end, so there was nothing leading me to believe it was crankwalked either before or after that clutch replacement. It chattered so bad with that sprung 6-puck that I'm sure that's what did most of the damage.

I would like to brand that M8 bolt the "Crankwalk Bolt"... so long as nobody else has done it already. I was lucky enough to catch it and include it in my transmission series and was concerned about what I found while taking it apart. Honestly, making the videos is making me a better mechanic because there's the pressure to quadruple-check myself and ensure I'm doing it right before letting the camera roll. Now I read the service manual sections, take notes, write scripts, read threads, check VFAQ's before posting. It's been like that since my 20th video. I'm not the brains behind any of this, it's the people like you who post your experiences... YOU are. Don't stop doing it, and I won't either.

 

[dsmtwins2g]

Yay been waiting for you to post,your videos are amazing awesome work man.

 

[dsmtun3r98gst]

Hey man thanks alot!!! great video. Great walkthrough on how to tear down a 4g63 engine.