Harmonic Balancer

[BodybyFisher]

I have been hearing what I thought was my AC Compressor making noise since its only a year old, I was a little concerned. The other day I got under the hood and listened, it does not sound like the compressor, it sounds like my harmonic balance, plus the balancer is wobbling a little... The right side of the carriage must be dropped to remove it. What are the odds that my balancer is shot, I don't recall anyone having one that made noise or wobbled...

I am doing my front brakes this weekend and will pull the inspection covers and get a closer listen at it...

Here is the procedure:

Crankshaft Balancer Replacement

Removal Procedure

Tools:

J 39411 Flywheel Holder

J 38416-B Crankshaft Balancer Remover

J 39344 Crankshaft Balancer Installer

1) Release the tension from the accessory drive belt.

2) Remove the accessory drive belt. Refer to Drive Belt Replacement

3) Raise the vehicle on the hoist.

4) Remove the right front wheel. Refer to Wheel Replacement in Tires and Wheels.

5) Remove the two splash shields from the wheelhouse. Refer to Splash Shield Replacement in Tires and Wheels.

6) Remove the brace between the engine oil pan and the transmission case.

Install flywheel holder J 39411 .

7) Remove the crankshaft balancer bolt.

8) Support the engine cradle with the tall screw jack.

9) Remove three engine cradle bolts at the right of the cradle.

10) Disconnect the RSS sensor from the right side lower control arm.

Lower the engine cradle to obtain clearance for the J 38416-B below the body rail.

11) Install pilot J 39344 into end of crankshaft.

12) Remove the crankshaft balancer using the J 38416-B .

Installation Procedure

1) Position the crankshaft balancer to the crankshaft.

2) Install the crankshaft balancer using the J 39344 .

3) Thoroughly clean the crankshaft balancer bolt threads.

4) Apply engine oil to the threads.

5) Install the crankshaft balancer bolt. Tighten

6) Tighten the crankshaft balancer bolt to 50 N·m (37 lb ft).

Notice

Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

The balancer bolt must be tightened an additional 120 degrees. Make a mark on the balancer bolt flange in line with the center line of one of the balancer legs.

7) Raise the engine cradle into position.

8) Install three cradle bolts. Tighten

9) Tighten the bolts to 100 N·m (74 lb ft).

10) Reconnect the suspension position sensors to the lower control arms.

Remove the J 39411 .

11) Install the oil pan to transmission brace. Tighten

12) Tighten the four bolts to 50 N·m (37 lb ft).

13) Install the wheel hose splash shields. Refer to Splash Shield Replacement in Tires and Wheels.

14) Install the right front wheel. Refer to Wheel Replacement in Tires and Wheels.

Lower the vehicle.

15) Install the accessory drive belt. Refer to Drive Belt Replacement .

[Cadillac Jim]

If you can see the harmonic balancer wobbling, I would just do it. If you can hear a noise, go for it. Procrastinating could cost you an engine.

I don't think it's a concern here, but, are there different harmonic balancers for best overall engine balance on the Northstar? Should we look at marks, part number suffixes, and such on the harmonic balancer and specify these when ordering to get the best possible engine balance?

The reason I ask this is that I recently got a Jasper remanufactured engine, and the engine balance on this non-GM engine is vastly better than the original. There is absolutely no noticeable engine vibration at any RPM clear to redline, at any throttle setting – not that there was anything I thought out-of-place on a Cadillac in the original. Jasper has a note on this engine, "Includes harmonic balancer." There are two most-often-used approaches for producing precision engines:

1. Individually balancing each component within tolerances.
2. Balancing each component as with the first approach but in addition specifying a range of balance parameters on one or two specific components such as the harmonic balancer and flywheel.

The first approach is most often used in production engines but produces good but less precise overall balance than the second method, particularly worst-case engine balance. The second method is more expensive and requires stocking a range of harmonic balancers but is appropriate for engines with redlines of 6,000 rpm and up, and that have long warranties -- but it produces engine balance in high volume production comparable to that obtained by having your engine balanced at a machine shop.

[growe3]

Although the balancer may be loose/separating, it is exceedingly rare for this to happen to the Northstar engine. More commonly what people see is a little casting anomaly, that makes the balancer look like it is wobbling.

If the balancer is separating, that is dangerous. At low engine speeds it is damaging, at high engine speeds it is a disaster. It should be easy to determine if the balancer is loose/separating by simply using your hands to apply pressure, rocking it sideways, there should not be any discernable movement.

If the balancer was loose, you would not have any oil pressure, as the balancer "pinches" the oil pump rotor, to pump the oil. Loose balancer = quick engine failure.

I would spend a little more time looking for another noise source. A/C or alternator perhaps, or maybe just worn engine bearings.

Sometimes normal engine noises can be misinterperted, higher mileage engines will make a little more noise.

If the balancer does turn out to be bad, I would replace it with an OEM unit.

-George