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2ZZ-GE tore apart my clutch, pressure plate and flywheel.

9510 Views 16 Replies 10 Participants Last post by  Smaay
2 days ago i finished my 2ZZ-GE swap, and curious thing happened as i was shifting from 3rd to 4th:

Everything went smooth with the shift, 4th engaged well and second and a half after the clutch was fully released it suddenly tried (as if i shifted Again) to overrev as if it went from 4th straight to 1st. The same millisecond it started raising the revs i kicked the clutch all the way down and released the car from gear (put it in neutral). I kicked the clutch back to the floor so fast that even the nose didn't dive into the road as if would've done if it locked in lower gear. The engine stopped and i heard pieces flying. I parked on the side of the road and tried to re-start the car. The engine wouldn't ignite. It turned like the battery was trying to die.

The following day we disassembled the car and found that a piece the size of a quite big coin was missing from the gearbox housing.

Piece of the clutch cover shattered, went straight trough the clutch disc, tore a hole in the gearbox housing and the flywheel cut trough all the bolts holding it to the crank shaft. The whole eight of them! When we separated the gear box from the engine the flywheel, clutch and the clutch cover were all in the bottom of the housing like a big salad. That's why (i guess) it didn't want to ignite the engine, since the starter didn't have full or any contact with the flywheel and didn't manage to spin the engine trough it, since it tore the bolts holding it apart.

My question is:
My reaction was astonishingly quick. I am almost 100% sure the engine didn't over-rev itself. from what it looks like the problem should be only in the flywheel-clutch department. The engine turns by hand like it should, no weird noises while turning it by hand.

Please guys, tell me there shouldn't be anything else damaged... And for Christ's sake, how the hell did that happen?!
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as long as the rpms didn't get to red line once it started climbing then you should be fine. the only problem you may have is the crank may need to be replaced if all the bolts holding the flywheel to the crank got sheered off. the force created to sheer the bolts may have bent the crank but not enough to see visually. as far as the gear box goes...........was it a rebuild a 5 speed or 6 speed you used to go with the swap?
it is a 2zz-ge 6 speed manual JDM gearbox.
Tomorrow we will ignite the engine since i have new clutch, clutch cover and flywheel bolts (*the flywheel itself is ok) and see if anything else is creating noises/problems... keep your fingers crossed guys.. :( i hope everything is ok with the engine.

edit: it will only bend a valve or something if the timing chain is off right?
timing chain should be unaffected. did you happen to re-use the flywheel bolts? post some pics, if you haven't already, i cant see them from work :(
i cannot post pics of the damage or car, it's in the shop right now, and i have no access to it... i forgot to take pics of it when it happened (i think you can understand me, i had greater issues in my mind) and literally hours after it happened the car was towed and torn apart by the mechanics in less than an hour. I hadn't had time to photo the problems...

and yes Smaay i reused the old bolts. We measured them, they were not stretched or eaten in any way...

I can't figure out what happened...
Saw this a bunch back in '00 & '01 in the over-rev hey-day. Pretty common at speeds of 10,500 RPM or greater. Most likely you hit second, not 4th.

But yeah - flywheel bolts are not supposed to be re-used, per Toyota.
Are you sure that flywheel botls didn't give away first? What bolts were you using.
you are not supposed to re use the flywheel bolts just by torquing them to specs they are become stretched. thats what they are supposed to do. you needed new ones or arp bolts. i think thats what happend. you accidentally shifted into 2nd and revved engine and since the bolts were not replace everything came off. hope everything turns out ok. get some apr bolts this time. good luck
@Dave: if i shifted to second shouldn't the engine immediately start to raise the rpm? Because it didn't... It went into forth and second or two after the shift was done, it started raising the RPM... I know how a car feels when you drop it in lower gear from high RPM without heel/toe shifting. this wasn't the case...

@GSBoek, i can't really tell what gave up first but the most supported theory is the clutch cover since it was obviously shot. My clutch was disengaging maybe an half of an inch from the carpet/floor.

@cuco, we measured the bolts to the 3rd number after the comma and they were in specs before putting them in the car. I am sure they were in oem condition. I measured them myself.

i really appreciate your help guys... thank you!

that sucks only 2 days after.
What you aren't understanding is that you shouldn't reuse the bolts, really it shouldn't have a spec when they say to replace them. The first time they are torqued, you stretch them. They probably started to work their way out and then broke off.
yeah.. Is the bolt sticking half way out with out the head?? Easy outs suck at least if you have some bit of bolt you can use vice grips and turn them out.
^ +1 for ****ty easy outs. think I have a at least 2 easy out tips stuck inside broken bolts on the car. both on one of the front fender bolts, Need to eventually get some harder bits to drill them out : /

I would bet that it was the flywheel that sheared off first and caused the rest of the damage. I can't even count the number of people who have re-used the bolts and gotten bitten because of it. If all you needed was a new clutch then you sir are very lucky indeed.

I know what you mean about being able to tell right away whether you've miss shifted or not. I know I've accidentally grabbed 2nd instead of 4th before and you can tell immediately by the way the nose dives and the speed at which the RPM's shoot up. Luckily both times I was downshifting from 5th to 4th so my RPM's were low and I was able to push the clutch back in before being in danger of over-revving the engine. It also helps that my replacement clutch is fully engaged a couple inches higher off the floor than it did stock
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probably hit 2nd. clutch slipped until it locked up.

i miss shifted in my celica with 60k on the clock. really bad. like top of 3rd. and limped it a good 5 miles or so before she wouldn't go anymore. it snapped my flywheel bolts off the crank. pitted and gouged the crank a bit. wallowed out my flywheel. the bolt holes were wallowed at the very last 2 threads on 2-3 of them. ran a tap through all the holes. slapped in a new flywheel, got some arp studs.

the flywheel actually rubbed and ate partially through my input shaft where the throw out bearing rides. and chewed up my bell housing. i was able to use belzona on the shaft and sand it smooth. found oil coming from my crank shaft bolt holes. (its a straight through design to the crank shaft caps.) replaced my rear main seal due to all the aluminum shavings from the the carnage in the bell housing.

basically i got away lucky with stock bolts. if i had arp studs they would not have broken and my head would have been toast. probably a piston or two. car has over 25k more miles since that accident and still runs like a dream. traded it in for what i have now and keep in contact with the kid who bought it. answer any questions he my have with it.

this is what happened to mine.

now my little brother picked up a celica with a blown engine in it and we did a swap on that. well a replacement 1zz for a 1zz and we had to replace the flywheel for the old one. my step dad was the guy incharge of it. i was just the kid with the tools and the know how from doing mine a few months before hand. and he was talking to our local toyota dealer getting parts and asked about the flywheel bolts. there 1zz-2zz guy says he always reuses them unless they appear to be stretched.

and his stock ones didn't stretch so he said just put some sealant to keep the oil in the crank and torque them to spec. i still wanted arp in there but it wasn't my money to be doing it. so they re-used the factory ones. and have a solid 15k on that engine. still no problems what so ever. if it ever gets miss shifted severely then yea, i'll bet they'll snap. but now there broken... arp is a good replacement set and cheaper then oem.

but thats me and my story. :)
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did you torque the bolts properly? they are 36 lbs plus another 90 degrees. and as for re-suing the bolts. Boosted, Toyota, everyone else, and myself demand that new bolts be used. but i have had to use bolts over again and have never had an issue with it. but what i do is clean the threads on a wire wheel and use new locktight, and torque to spec
Pool Playen Bob thank you for chiming in man, i really appreciate your post!

Smaay: i will use new bolts now, just trying to figure out the cause of the problem
And yes, they were torqued to spec and degrees.

thanks again for the help and support guys!
its cheaper to get the ARP bolts from MWR than OEM bolts. those can be re-used
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