BHJ Harmonic Balancer Installation

A common problem with the stock harmonic balancer aka vibration damper is it's prone to cracking at the snout.

BHJ is the only aftermarket balancer offered for the 3.8L engine. The balancer is "Neutral Balanced" which means it has no counter weights added to it for proper engine balancing. All Supercoupe engines uses the neutral balanced balancer on all 1989-1995 cars. BHJ harmonic damper features a TDC mark and are degreed from 0 to 10 degrees ATC and 0 to 50 degrees BTC in 2-degree increments for accurate ignition timing. I suggest adding numbers using a dremmel type tool to scribe into the metal. Since the balancer is steel I suggest spraying a coat of clear high temp paint to prevent rust.


 

Before Installing the BHJ you will need to replace the OEM balancer bolt which is grade 10.9 M14 x 40mm x1.5 pitch
with a longer grade 10.9 M14 x 50mm x 1.5 pitch bolt.

MN12 Performance Inc. offers the correct bolt/washer needed when installing a BHJ on your SC for $6.
E-mail richt@mn12performance.com or call 703-968-6513

The reason for needing a longer bolt is the stock OEM balancer has a 2" snout depth while the BHJ has a 2.5" snout depth.

Remove the OEM balancer using a balancer puller. These can usually be rented or loaned from most autoparts stores.
The pulley uses M8 x 1.25 pitch threads. Ford OEM balancer removal tool is part number T58P-6316-D or
OTC part 303-009 retail price is $80

Check the crankshaft snout for and nicks and clean.
File down any nicks before installing the BHJ balancer to prevent problems.

Now you will need to remove the crankshaft timing ring and install it on the BHJ.
Remove the timing ring from the OEM crank and clean. 4 bolts hold the timing ring in place.
Brake cleaner, compressed air will work.
When all 4 holes on the BHJ are lined with the timing ring holes you are ready to install the 4 bolts.
Add some locktite thread locker and Torque to 8-10 ft-lb

Note: A digital gauge is helpful to verify balancer ID before installing on crankshaft.
My crankshaft diameter is 1.385" while the BHJ ID was 1.355".
I used a digital mic to verify the two diameters.
I removed .015" from the ID of the BHJ to provide the proper tolerance of .001" - .0015" per BHJ specifications.


 

Apply gasket sealer to the slot in the balancer before installing. This will keep oil from leaking
out of the balancer via the keyway.

You can use a balancer install tool which OTC sells. This one is Ford part number T82L-6316-A or
OTC part 303-175 retail price is $40
 

Install the new balancer over the crankshaft snout until it is fully seated.
Torque the NEW damper bolt to 110 - 130 ft-lb.

To hold the engine from rotating while tightening the crank bolt you can access the flywheel from
the access cover plate at the bottom of the transmission and using a wrench or wratchet to keep
the engine from rotating. My choice is a screw driver inserted through the flexplate or flywheel.

Add a little color to the timing marker will help if you need to check the timing. If you need to
reinstall the Cam Position sensor you will need to find 26 degrees ATC on the balancer which is
1.30" from TDC mark on the balancer. Easiest way to locate the 26 degree mark is to cut out a
piece of masking tape 1.30" long and place on the timing marks starting at TDC.



 
MN12 Performance Inc.
richt@mn12performance.com
www.mn12performance.com
703-968-6513