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HELP Changing Crank Position Sensor

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Old 11-06-2005, 11:12 PM
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Default HELP Changing Crank Position Sensor

Hello from Pennock'* Fiero Forum (http://www.fiero.nl)!

My brother has a serious problem with his only car - 88 Bonneville LE, don't know what version of the 3.8 v6 but I want to say vin code C. EDIT: I'm pretty sure a "3.8" something, not a "3800". He needs to replace his crank position sensor, but for some reason or another he can't just remove the alternator to get to the flywheel to keep things from spinning while he takes off the crank shaft pully nut.

My uncle, a great mechanic, says if he remembers correctly you can put a wrench on the crank shaft pully nut, brace the other end on something, and turn the engine over and the rotation will break the nut free.

For obvious reasons, my brother is afraid to try this without knowing the threading direction of the nut and the rotation direction of the engine. Which way does the engine turn? I haven't been under the car so I don't know which end of the engine this is on either.

Any help is welcome! Thank you!

- Jason
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Old 11-07-2005, 11:24 AM
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Default nut

I have heard of people on the board doing this with a breaker bar although I never tried it nor would recommend it.
You simply need to wedge a screwdriver in the flywheel while someone turns the bolt with a large breaker bar.
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Old 11-07-2005, 12:16 PM
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Default Re: nut

Originally Posted by SSEBONNE4EVA
I have heard of people on the board doing this with a breaker bar although I never tried it nor would recommend it.
You simply need to wedge a screwdriver in the flywheel while someone turns the bolt with a large breaker bar.
you mean starter perhaps that you dont recommend?

you can also use a tire iron instead of a screw driver for better leverage and sturdyness. we ended up going and getting a 24in breaker bar, impact sockets, and going at it from the top, before it finally broke loose. happy hunting <btw, you can also rent an impact gun if you like. we did, but burned up the gun, and broke a socket on this bolt. your results may vary>
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Old 11-07-2005, 12:45 PM
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Take the car to a shop, and have a tech remove it with an impact. Electrics prolly don't work as well.

BTW, if that bolt is on tight like that, then you prolly will need to have the shop remove it, with an air hammer. I've had to remove a balancer this way. Maybe its best to take it to the shop anyways, since it costs about 1/2 hours labour, and another 20 for the part.
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Old 11-07-2005, 05:22 PM
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Best way I found in removing the hermonic balancer is to take a pair of vice grips, and clamp them on the fly wheel and this will keep the engine from turning while you put a breaker bar on the hermonic balancer bolt. Worked great for me on the 95 Bonnie. Of course, your going to have to move the tire to gain access to the hermonic balancer and bolt. Make sure that you align the crank sensor properly, or else you will have problems down the road.
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Old 11-07-2005, 05:30 PM
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Thanks again. Looks like my previous post didn't show up. What I said was there'* probably not going to be access to the flywheel because I think he hit a ditch and bent something that'* now obstructing things.

I also wanted to confirm whether the engine rotates in the correct direction to do what I proposed with the starter motor.

Anyone have instructions for properly aligning the crank sensor? I'll take a look around.

Thanks again
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Old 11-07-2005, 07:15 PM
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You should be able to access the fly wheel very easily. On the bottom side of the engine, there is a dust cover that is held on by 3 10mm bolts. Remove this dust cover and you will have access to the fly wheel. Its almost impossible to bend something that wouldn't able you to access the fly wheel. For example, the oil pan would have to be smashed up in pieces and obviously the car wouldn't run. Just like I said take a pair of vice grips, lock them on the fly wheel and in return the vice grips will keep the engine from turning so you can loosen the hermonic balancer bolt.
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Old 11-07-2005, 07:47 PM
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Thanks again. I'll have him try this and hopefully everything will work fine.
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Old 11-09-2005, 07:18 PM
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yeah I meant starter....
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Old 11-09-2005, 08:09 PM
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Welcome to BC...

I just did my harmonic balancer a weekend or two ago, and removing the bolt on the crank is tough. I am not familiar with the 3.8 (LG3) but on the 3800 (LN3) I just had to remove that small plastic dust cover and wedge a flathead screwdriver in the flywheel gear teeth. Then I used a big box-end wrench, and exhaust pipe on the end of that for extra leverage. Get someone to hold the screwdriver and have at it...I got mine off in two heaves. This is all assuming the LG3 is quite similar to the LN3 in those respects...
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