Six Bolt Crankwalk!

Irratic clutch pedal
Jittery and High oil Pressure
No power above 4k
Knocking/Rattle sounds not allways
Throwout bearing Hiss sound when clutch is engauged in neutral
Tranny whine, most often in first after a cold warm-up

The crankshaft has 1/4" or more Play, I'm Sure the thrust bearing is toast or just gone.
so If your plauged with any of those issues or all of them like me, and you have a six
bolt that was "rebuilt" by god knows who. Dont leave this out of things to check like i did /ubbthreads/images/graemlins/banghead.gif


This is a sad day, But its still running and driving for now.
When it comes time to pop a shortblock in it I'll be posting pic's in detail to see why
this 6bolt failed, My guess is the p.o.'s "rebuild".

 

[CutlassJim]

Not the first 6 bolt I've seen crankwalk.

 

[Struc]

The 6-bolt in my GVR4 walked as well, but I attribute it to a moron rebulid. They put in ARP Main studs, but I'd bet good money they didn't have it line honed, based on the rest of the rebuild.

 

[DynastyLCD]

ive seen it twice. once on a fresh rebuild with zero miles on it, the guy never unplugged the clutch switch and they couldnt get it to start due to other issues, so the car was cranked on only cranking oil pressure with the clutch in the whole time. the other was a 20k rebuild that was utilizing an ACT2600. high torque pressure plates will attribute to thrust bearing wear faster than a stock clutch or a lighter pressure plate. this was one of the selling points on the twin disc as a very reputable transmission builder had explained to me it reduces the chances of crankwalk by at least half. but then again, i think Curtis walked his with a PTT in it (correct me if im wrong)

 

[alansupra94]

Yeah disabling the clutch switch is one of the first things you should do.

In theory, that twin clutches reduce crankwalk chances but I am not sure by how much.

 

[blackvr4]

Quoting Struc:
They put in ARP Main studs, but I'd bet good money they didn't have it line honed, based on the rest of the rebuild.



that is such a misconception when it comes to ARP mainstuds. I put them into my own engine when I had it apart and it has over 15K on it problem free. But I have read numerous threads along the lines of ARP mainstuds + No line honing = imminent death. I just thought about it long and hard and it didnt make any sense to me.

 

[GSX_TC]

I would just like to add that I have a 6bolt with arp main's that didn't get line honed and has an act 2600 clutch and about 30,000+ hard driven miles on it. Still runs like a champ. No problems. So I will be living proof that is just a myth

 

[Overkill]

I don't see why main studs would cause the main caps to mis-align and crank walk is a symptom of oil starvation not mis-aligned caps

 

[broxma]

The premise is the greater clamping force cause the bore to distort, which is not true. Roughly the same pressure is applied with stock bolts and ARP's within the tolerance of the block. The ARP's are just studs not bolts and therefore naturally stronger. The heavy clutch, low oil scenarios are much more likely.

/brox

 

[curtis]

Bet it was balance shaft removed without spinning the bearing or some other problem like oil cooler not replaced after last blown up motor and or years of heavy clutches and car didn't idle well and was started alot. I've seen all problems more than once with cars and my buddies shop.