Crankshaft key problem...

[plaaya69]

So I'm changing my timing belt on my 87 Turbo supra and I remove the bolt that holds on the crankshaft pully and I notice that the bolt comes right off(no way near like its been torqued to 195ft lbs) also not only that but the key and part where the key sits in on the crankshaft is bad (which I know can be caused by that bolt being loose).

My question is can I get this fixed so the key will fit like it should? with the crank in the car? because the right side and the top and botton of the keyway in the crank is fine but the left side is bad. Here is a pic

 

[figgie]

not with the crank installed. that is a rounded keyhole =(

need to have metal welded on and then machined.

 

[supraguy@aol]

I know this answer won't make most people on here happy, but way back when, I had the same exact problem with my 7MGE. I had someone weld on material(Chris was his name- drove a 7MGTE MKII in GA) to the crank while the engine was in the car. We took out the radiator and he MIG welded in some steel to the left side of the keyway. Once he finished, we used a die grinder to cut down any material above the keyway so that the crank pulley would fit properly, and then used a small bit to cut the left wall back to vertical. It worked flawlessly. Of course, results may vary, but I just wanted to say that this worked for me.

 

[figgie]

I know this answer won't make most people on here happy, but way back when, I had the same exact problem with my 7MGE. I had someone weld on material(Chris was his name- drove a 7MGTE MKII in GA) to the crank while the engine was in the car. We took out the radiator and he MIG welded in some steel to the left side of the keyway. Once he finished, we used a die grinder to cut down any material above the keyway so that the crank pulley would fit properly, and then used a small bit to cut the left wall back to vertical. It worked flawlessly. Of course, results may vary, but I just wanted to say that this worked for me.

let say you just bought a nice shiney new ATI damped pulley. Would you put that pulley on the line on that "cletus rig"?

 

[GrimJack]

It's actually possible to do it in the car, but it's really unlikely - it's easier by far to pull the engine. An expert millwright would have access to the tools to recut the keyway properly on both the crank and the pulley bits, and he would likely cut it 180 out from the original.

The difficulty comes from the front bumper... it has to come off, as well as the radiator, AC condensor, fans, intercooler, horn, oil cooler, etc, etc. Basically you need to strip the front end, and even then it's a pain to fit the cutter in there. Then you need to purge and recharge your AC, which is another pain, especially if it's not been refitted to R134a already.

 

[Zumtizzle]

It's actually possible to do it in the car, but it's really unlikely - it's easier by far to pull the engine. An expert millwright would have access to the tools to recut the keyway properly on both the crank and the pulley bits, and he would likely cut it 180 out from the original.

The difficulty comes from the front bumper... it has to come off, as well as the radiator, AC condensor, fans, intercooler, horn, oil cooler, etc, etc. Basically you need to strip the front end, and even then it's a pain to fit the cutter in there. Then you need to purge and recharge your AC, which is another pain, especially if it's not been refitted to R134a already.

this job will require a few redbulls.

 

[supraguy@aol]

let say you just bought a nice shiney new ATI damped pulley. Would you put that pulley on the line on that "cletus rig"?

Let's say I just told you I did this to a 7MGE. Why would I put a $700 damper on that? But since you ask, AND since the keyway lasted for the remainder of the engine's life(till it was swapped out for a turbo 2 yrs later), then i guess I'd say yes.
Like I said, most people weren't going to like that I did the repair in-car.

 

[figgie]

Let's say I just told you I did this to a 7MGE. Why would I put a $700 damper on that? But since you ask, AND since the keyway lasted for the remainder of the engine's life(till it was swapped out for a turbo 2 yrs later), then i guess I'd say yes.
Like I said, most people weren't going to like that I did the repair in-car.

$400 actually.

Then you would have one failed dampner on top of that. Likeing the answer. Irrelevant. The answer is wrong. The snout of the crank has to have full contact on the damper 360 around to be of any use. Any other "rig up" will just lead to lose dampners in the future.

again. Zero to do with liking it. Do it correctly or do it the cletus way. Quite that simple.

 

[plaaya69]

Thanks for the responses.

The thing is that I removed all a/c components and everything but the bumper right now is in the front(im changing out alot of parts) and also it seems weird because I noticed the pulley would wobble verry verry little when the engine was running and I want to get this fixed but I dont want to take the motor out and tear it down because it is very strong good motor and has 160psi across the board. I have a jdm motor that I would want to rebuild and drop a few years from now in but I do not want to do that at this time.

 

[shaeff]

Starting at post # 337, though I don't recommend doing this it held up at over 300rwhp for a while til he blew the motor. (and it held up through that, too)

http://www.supramania.com/forums/showthread.php?t=29149&highlight=crank&page=7

 

[HommerSimpson]

I've welded a few dampners right to crank for a a few custmers over the years...

There is always a right way and a wrong way and the easy way that will work...

myself if i was going to pull motor out to fix crank...

I would just get a GOOD crank.. instead of fixing keyway...

 

[plaaya69]

Starting at post # 337, though I don't recommend doing this it held up at over 300rwhp for a while til he blew the motor. (and it held up through that, too)

http://www.supramania.com/forums/showthread.php?t=29149&highlight=crank&page=7

Thanks for that information. I will either try that or I will try and weld the crank and make the key work. I will be buying a new key eventhough mine is not that bad and its been holding up good before I took everything appart and the crank pulley is in good shape. Either way I have a spare jdm that I will rebuild soon in the future but not at this time.

 

[suprarich]

If you pull the motor, you don't need to pull the head or pistons to remove the crank.

The way I fix them is to install a false key made of carbon into the slot. Then build up around it with weld. Then I knock the carbon out of the slot leaving behind a nice keyway. Then the crank has to be ground on a crankshaft grinder to remove the excess weld. I have pics posted somewhere on SM of a crank I did like this.

 

[grimreaper]

ouch, im about to pull the front main seal ( small leak) and PRAY i dont find this. good thing i lend a hand at the top fuel hydro shop near by, talk about knowledge and extreme capabilities.... post up what you end up doing....