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Discussion Starter #1
the slot looks real bad where the cresent shaped key is inserted for the harmonic balancer/ crank pulley. ( the crank pulley is completly destroyed, the hole in the crank pulley is much much larger then the crankshaft.) big time wobble!!

I also found the pulley for the cam shaft drive on the crank had a ton of slop and that key was just about down to nothing left. Its a wonder the car ran at all!

Problem is this cam drive pully and key was brand new a year ago. What am I doing wrong for this to happen to me twice?? I do have replacement pulleys in very good shape...( new keys of course)

As far as the crank pully key, the slot looks bad.. maybe I can weld in the new key(just the left side of the slot looks bad since that is the driving side) and dremel off the excess.. I feel like welding both pulleys to the crank.

Any feedback is welcome, I am very depressed over this .. I may have to replace the whole crank shaft..again! :(
 

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I've seen this problem with the M series engines before. The 1st Gen Supra engines were really bad about this happening. To fix it properly. You will need a new crank and pulleys. I have seen a tech that fix it on his own car. By welding the pulleys to the crank. Like you said you might do. I sure there must be some others here. Who have had this same problem.
 

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well, did you replace the crank bolt and tq it properly? if not thats what did it. what happens is the bolt in the snout of the crank stretches and when you try to tighten it back up, it is bottoming out in the crank instead of tightening the pulley down. if the pulley isnt tightened properly, it will vibrate and slowly wear the key and keyway out, and eventually ruin the crank and pulleys as yours did. you can weld the keys in the crank and grind the excess off but dont expect it to last forever. the best fix is a new crank, pulleys, and bolt. the bolt is ~$7 from toyota. if you weld the keys in be sure to gt a new bolt and tq it to 195lbs/ft and youll be ok. dont use an impact gun, it will cause a whole other set of problems, like bottoming out the bolt in the crank and smashing it so when you remove the bolt to do a timing belt change the threads in the crank will be fubar. btdt thanks to the moron that did that when the timing belt was changedon my 83. i almost installed the 5mge i have with 9kmi.
william
 

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I have just started with toyota's but we used to get this problem with out GTti track car's.

Car was alway's running in the 6000-9500 rpm range and the woodruff's were not up to the job.

What we ended up doing was spraying the crank oversize then maching back to size and then milling a straight keyway slot in place of the woodruff.

The woodruff on the motors we used drove both the cambelt gear and the harmonic balancer.

Once the mod was performed we never had the problem again.

Hope this helps.
 

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williamb82 said:
well, did you replace the crank bolt and tq it properly? if not thats what did it. what happens is the bolt in the snout of the crank stretches and when you try to tighten it back up, it is bottoming out in the crank instead of tightening the pulley down. if the pulley isnt tightened properly, it will vibrate and slowly wear the key and keyway out, and eventually ruin the crank and pulleys as yours did. you can weld the keys in the crank and grind the excess off but dont expect it to last forever. the best fix is a new crank, pulleys, and bolt. the bolt is ~$7 from toyota. if you weld the keys in be sure to gt a new bolt and tq it to 195lbs/ft and youll be ok. dont use an impact gun, it will cause a whole other set of problems, like bottoming out the bolt in the crank and smashing it so when you remove the bolt to do a timing belt change the threads in the crank will be fubar. btdt thanks to the moron that did that when the timing belt was changedon my 83. i almost installed the 5mge i have with 9kmi.
william
williamb82 is correct: the bolt wasn't torqued properly. had the same problem with my mother-in-laws cressida. sounded like stuck lifter, but the woodruf key had worn out the pulley to the point that it had about 30 degrees free play, ahd it ran like s***. i was able to use a nail pulller from home depot (divine inspiration) to remove the worn out key. got key, crank and cam gears, good timing belt, and cover from pic-a-part for about $20. been running like a top for the past 3 months.

the key is proper torque. the hack mechanic that worked on the car before me tried to use locktite to keep the bolt on :dumbass:
 

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the key is not just the proper tq, but to replace the bolt as well. a new bolt is like $7 tops from toyota and the timing belt is changed every 60kmi so its very cheap insurance.
william
 

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williamb82 said:
the key is not just the proper tq, but to replace the bolt as well. a new bolt is like $7 tops from toyota and the timing belt is changed every 60kmi so its very cheap insurance.
william
good point. my '82 has over 350,000 miles on the same bolt, but it's never been over tourqued. i didn't know the history of my mother-in-laws car, so i did replace the bolt, as well as the harmonic balancer.
 

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Discussion Starter #8
Thanks guys for that info.. now I know.. I did it all wrong...

I reused the same bolt and I torqed it using the impact driver.. so

New bolt will be here monday $10.50 and my tq wrench goes to 150 so I guess i can use that to get it 159 ft/lbs. I made a tool to wedgeinto the starter hole and hold the flywheel. Thats how I broke the bolt out of my spare 85.

I also converted from square toothed cam belt to rounded tooth and got rid of the old 2 x 'V' belt alternator and upgraded to serpentine.

I will let you know how it goes with trying to repair the key slot with my wire welder and a dremel... some jb-weld and alot of Loctite ( bearing retainer ) non removeable.
 

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well, the bolt is supposed to be tqed to 195lbs/ft. also, just cause the bolt was never over tqed doesnt mean anything, when you tq the bolt it stretches, and eventually will stretch out too far and start bottoming out in the crank, so instead of it being 195 ftlbs holding the pulley on, it is pushed against the crank at 195ftlbs and the pulley may only be feeling 20lbs ft. maybe more maybe less, but either way i hope you get my point. the bolt just wears out and in my opinion, its best to replace it every timing belt change.
william
 

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Discussion Starter #10
Thanks William, I just installed the new bolt , keys, pulleys and torged to 159 as per the manual.. Everything seems fine so far but tomorrow I will retorque to 195 lbs per your suggestion..
Thanks again , you guys taught me alot.. and I know I have alot more to learn.
 
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