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Replacing Harmonic Balancer on '90 Buick Lesabre

03-23-2005, 08:56 AM
I discovered that the harmonic balancer on my '90 buick lesabre (3.8l)needed to be replaced.
After reading up on it I decided I could do myself. I got a balancer from the wreckers and was able to install with not much difficulty.
However once I had everything back together and tried to start, it would not. Cranked fine but no fire. Now I think the balancer I got was off a '88 and I noticed the fins on the back side of the balancer seem to be different from the one I rermoved from my car. The balancer I removed from my car has two sets and the one I installed only has one. Are these fins what the cam shaft sensor times on, and because they are different won't allow my car to start. If this is the problem can the fins be swapped fron one unit to the other.

Any info on what might be happening would be greatly appreciated.

03-24-2005, 08:11 AM
I was able to find the answer I needed by lookinng a litttle closer at the Haynes manual. The "vanes" as the book describes are for the crankshaft timing. Faulty, or missing in my case, vanes will cause a no start condition. Will swap for the correct balancer.

03-31-2005, 10:56 AM
I'm having fun replying to my own post, but if anyone is looking for info on replacing the balancer hopefully this will help.
I did get the correct balancer and installed, runs great now.
Tips for changing:
As described in the haynes manual, remove the cover from the flywheel and have some one hold a large screwdriver in the teeth to stop from turning ( I had my 11yr old son do this), then use a 15/16th socket and large bar to loosen nut holding balancer on. It is very tight but I was able to get off fairly easily using this method.
Then simply put on the new one lining up the slot in the balancer with the key on the shaft and tighten using the method above to secure the flywheel.
Replace the belt and your off to the races.

03-31-2005, 11:32 AM
Clamping a visegrips on the flywheel works too if you are working alone.

01-12-2006, 09:16 PM
I'm glad you put this info here. Was changing crank senser and tightened balancer bolt as far as I could by holding with hand. Tried to start and nothing .Hoping it's just not quite close enough to senser. Put wrench handle in and it seemed maybe 1/2 in. longer than bolt.
How do you know when it is in far enough?

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