Crankshaft not centered

Hi - I had my clutch blow out and the flywheel too, this was replaced but there was a engine vibration that my tech said could be a bad flywheel. On opening he said that the crankshaft is not centered and that the engine replacement is the most ideal solution. Below are two images one of the crankshaft alignment tool that does not fit due to the crankshaft being not centered (there is a gap on the top and no gap below). Is engine replacement my only solution. Thanks

what? OK in order for that to happen the cradle would have to have shifted off...OR the crank is bent (more likely) rotate the cranck and check again if the motor runs my guess is that the cradle did NOT move report findings

The motor runs, with the new clutch it runs but the clutch feels funny and there is a vibration that can be felt through the clutch.

light weight flywheel / or stock dual mass? for $15k I want to know more before I start throwing away a running engine - contact Jake Raby (google search him) start gathering info and tell that tech to hang on!!

Stock flywheel. I will contact Jake Raby. Thank you for the information.

Have him put a dial indicator on the sealing surface of the crank and rotate crank. He'll be able to see any wobble on the indicator. Sounds like the crank got bent. Replacement is the standard fix. Phil

I just spoke to him and he is checking, should have the answer in 15 mins. Is it as expensive to replace the crankshaft. According to him it sounds like they both cost the same.

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Yeah, sorry. What I meant was engine replacement is the standard fix for a bad crank. Your mechanic is being square with you there. Sorry, this must be a huge bummer for you. Phil

Unfortunately that is why the go-no-go gauge is used in RMS issues and they usually have to replace the engine if out of spec. Hopefully there is another solution, if not rebuilt eng's from Porsche or good Indies (Autusse Newport) and offer 1 and 2 year warranties.

Just confirmed that the checking tool goes in when the crank is rotated. So in one position it goes in and in the other there is a gap and does not.

Confirmed this info is 100% true - just had a long talk with the people in the know - sorry man, that suck major donkey d!ck!!!

So what is the total runout? You need that number.

So if the crank is out of spec, (nicer term then bent!) what would cause this? Over rev? A bearing die and overheat a section of the crank allowing it to twist or distort?? Anyone?

so IF the crank is off center (and not bent) what happens is the seal will never seal. Turns out the cradle was most likely machined off center at the factory and was never caught. The tool designed to check concentricity is pretty simple to use and give a GO/NO-GO result. If the motor is deamed out of range by the tool it must be replaced. There is NO fix and even rebuilding it would require a donor motor to make it right... The other thing that "could" be wrong is a bent crank due to the flywheel/clutch issue. In this case if the motor is continued to run the crank will frac. and the rear section with the flywheel /chutch most likely will saw thru the bell housing and leave the car needing a new motor AND transmission. Well - the news is just wonderful today (and seriously to the OP I feel rotten for you) A call to Jake raby will confirm this info and according to what I have heard, there is not much even he can do. i would imagine he knows a few tricks and might be able to coax you thru a thourough checking to issolate exactly what is the problem and lead you down the correct path.... but be prepared, there is an extreamly high likelyhood that your motor is toast and needs to be replaced again, so sorry about the news to answer above - the crack might have become damaged when whatever the OP called "clutch blow out and flywheel too" took place ?????

The crank and supporting bearings are held in a girdle or cage which is bolted into the crankcase halves. The crank can be pefectly true, yet due to machining tolerances and other issues, the crank may not be concentric with the RMS bore in the case. This is one reason there are RMS leaking issues. The go/no go tool checks the crank to case concentricity to determin if a seal will adaquetly hold back the oil in the case. Seals are somewhat forgiving but not if variances are too great. Another thing, with all the RMS issues, I'd bet that RMS bore in the case halves is not individually machined using the center of the girdle that will be used in that very case. If it was, the RMS bore would be on center with girdle, and there would be no concentricity issues.

I would think that that if the crank was true but off center then it would not vary with rotation. It should be the same offset even with rotation. So if a dial indicator is on the crank and it is showing a variation, then the crank. or at least the flange must be bent or out of true.

"So in one position it goes in and in the other there is a gap and does not." Bent crank from the flywheel\clutch mishap. If it were not concentric it would be tight on the same side when rotated. Bent would be 'tight' moves with the crank.

Still waiting to hear back from Jake Raby, as of now I guess new engine is my only option?

you have to talk to the pro's sadly the outlook is not good but like I said if you can get the real experts on it, they may know a way to diagnos it further and pinpoint the problem and if the problem falls into the right bucket, they may know a fix... its a longshot but you have nothing to loose

Rolling Art. Love the paint job. What color is that? It's Billy Bad ***!

So the car runs but the clutch pedal has a vibration to it? Personally I'd run it till it blows up if ever.

tough call... it must be diagnosed as running it could lead to a dangerous and more costly repair (ie the flywheel rattles around in the bell housing.... unlikely but the vibration is telling you something more than your RMS isnt sealing)

Wouldn't be the first time a crank cracked/broke and hangs in there still running/rotating. 4 bolt mains have done it and I think I recall the 996 is around 6 or more bolts. Doesn't look good with the out of line crank. Looking at the present doom the first thing I'd think is compair plain jane engine replacement to radical add ons to correct the problem. Could be a good chance to make a race engine.

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Thanks for the compliment. I should change my name to Billy then? It's a "Paint To Sample" car, painted in Riviera Blue. It was a color Porsche used sparingly in the '90s on the 993 model line of the 911. There are a couple RLers with Riviera 993 cabs . And a question for the OP. What happened to your clutch to cause such catastrophic failure? I don't believe this is very common. Did the parts simply fail or was there any driver involvement here? And again, this really sucks. Phil

This sounds like something which happened on PorscheClubGreatBritian (PCGB)... Here's the link http://www.porscheclubgbforum.com/tm...&mpage=1&key=& . You need to subscribe, but here's the text...

I received the email from the original poster. I'll reply here. First, a question: Was this engine suffering from RMS leakage prior to being disassembled? From the pics it looks to have been mostly dry with only some residual oil being noted from the old seal extraction. This issue of the crank not being centered is actually due to the entire crankshaft carrier not being centered within the block halves. We have developed a method of repairing this with the engine disassembled, but there is no cure for it if still together except a full tear down. If taken to a facility filled with "rule followers" and book readers the only solution would be to replace the engine, or pull it apart and have us do the required work to re-center, which would cost more than a new engine. If I was in this position and the RMS was not leaking prior to disassembly I'd apply the newest Porsche RMS, put it back together and hope like hell it didn't leak. The new seals are very durable and they do conform to changes in the positioning of the seal flange more than the originals. I'd say if it wasn't leaking before you have a good chance that it won't leak again with the new seal, but it is a risk that could lead to wasted dollars for reassembly.... or it could lead to a lot of savings. According to the "book" you are screwed, but in reality you might not be. Are you a gambling man?

There ya go !! and Jake - THANKS for stopping by !!

Well, Sorry but Jake obviously didn't read this whole thread nor get all the details in the one email he was sent. If the crank was off center, the GO - NO GO tool would not be able to GO at all, at any position of crank rotation. If you put a dial indicator on the end of that crank and rotate it, you'd have the exact answer. No more questions. There is also the issue of the vibration. I like my idea better than Jake's. There's no way I'd put this back together without checking (especially since we already know the crank is damaged by the use of the G -NG tool) the run out of the crank and just hope for a miracle. Phil

OH dont get me wrong I agree you have to find whats causing the vibration - Jake only pointed out what one could do about the RMS issue and did not address the vibration at all... my first reply said you have to rotate the crank and see (measure) whats going on AND I also said IF the crank is bent it could frac and be a bigger repair... So NO the diagnostics are not over... but if that end checks out, the statement Jake made is valid (but ONLY then)

I made my post based on the email he sent me.. Was a vibration there before? You do know that new clutch components and flywheels are marginally balanced, right? If the issue wasn't there before I'd doubt the vibration is the crank.. A crank is hard as hell and tough as nails, it would be hard to damage, BUT i have seen installers put flywheels back in place that were not seated properly to the crankshaft, causing a vibration.

I think that raises a good point - and back to the OP about this "clutch blow out" which we still dont know what means... but if the clutch just went out and didnt explode otr anything and there was no vibration before the clutch job and there was after... why was the RMS removed.. again Jake, I know its been tough to stop in here and thanks for your input - you said the engines that are not centered can be "fixed" thru a full teardown and some machine work and rebuilt?? That is differant than I heard. I was told there needed to be a donor motor, but if you can re-machine the cradle/case mouonting to allign the crank and rear bore that is good news (still not cheap, but good to know) I have said again and again this is not a cure for the vibration if it is a simple case of mis-alignment... but if thats all that is wrong AND you can get it to seal via the amount of available "play" in the seal... I would not be replacing that motor - find the smoking gun causing the vibration (clutch/flywheel suspect) OH and why not pop in an IMS retrofit while you have this all apart? (I sound like a broken record)

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No the tech confirmed that there was no RMS leak when he opened to replace the engine the first time. Will speak to the tech about putting in a new RMS and report back. Thank you

The clutch went out and a friend of mine was driving, he continued to drive which cause the flywheel to go out and push to get off the freeway until the engine started to smoke and vibrate :-( i will never let anyone take my car out again. This is the second time :-(

send your "friend" the bill OK so back to the original Q: the clutch went out when some one else was driving... but ?not blown up" the engine was smoking???? and vibrating???? clutch was replaced, engine still vibrates, tech then removes RMS and says get a new motor... this story has more to it and we are having trouble helping w/o more detailed info

A clutch when burning it will smoke really bad. Being a clown unfamiliar with driving a car smoked his clutch thinking he was smoking the tires I imagine he kept smoking the clutch to aparently the death of more than the clutch. I'm not sure how far along the shafts the glowing heat of the metal will transmit but it seems it went as far as the rms to smoke it too. Porsche has no plan to add a little voice to broadcast "I'm giving it all she can take captain, she can't take it much longer captain" Yah screw letting clowns drive what you've got.

sounds like you can just start throweing money at it as any time! Good luck. But it sounds like the only Sure zing is anzother motor.

getting a new motor, it will arrive later this week. Thank you for all the help. Regards.