Mustang MonthlyHow To Engine
How to Install a Harmonic Balancer Repair Sleeve
Save yourself hundreds of dollars and major engine disassembly with this age-old repair trick
“A repair sleeve will fix the end of your harmonic balancer. No need to buy a new one,” Bob Becker said. I had to be persuaded. A new part almost always sounds better to me than a repaired part. The grooves on the mounting surface of my harmonic balancer looked unfixable. I wanted to make sure oil didn’t continue to leak past these grooves.
“How much for a new harmonic balancer for my 289?” I asked Bob.
“Around a $100,” was Bob’s reply.
“How much for a repair sleeve?” was my next question.
“$5-$6,” replied Bob.
I was coming around to Bob’s way of thinking. He builds engines on a daily basis—for a living. Bob showed me a repair sleeve. I could see how installing this sleeve over the end of the harmonic balancer’s worn and damaged mounting surface would essentially create a smooth, new surface, making it as good as new. It was time to break out the camera and show Mustang Monthly readers this simple, yet effective money-saving repair.
Editor’s Note: After freelance writer/photographer Jerry Heasley dropped the 289 into his 1968 Mustang convertible project in the Oct. ’14 issue of Mustang Monthly an oil leak was noticed at the front crankshaft seal area after that story went to press. With a rebuilt and running engine already in place the diagnostic work of Jerry’s friend, Bob Becker, deduced the leak was from a grooved harmonic balancer, a common issue on older Ford engines. We pick up this story where Bob and Jerry were discussing the best course of action to repair the leak. Read on and enjoy.
01. Bob held up my 289’s harmonic balancer to reveal two grooves that allow oil to leak past the end of the crankshaft seal installed in the timing cover.
02. To install a repair sleeve (middle bottom row) on a harmonic balancer (upper right), you will need a hammer, a wooden block, and steel wool.
03. You also need a few common kitchen appliances: a freezer and a stove, plus a pan to boil hot water, and a set of tongs.
04. Rub the steel wool over the end of the harmonic balancer until smooth and clean, as seen here.
05. Place the harmonic balancer in the family freezer for a couple hours to shrink the metal as much as possible.
06. Immerse the repair sleeve into boiling water for a couple minutes to expand the metal as much as possible.
07. Pull the ice-cold harmonic balancer out of the freezer. Align the hot repair sleeve, using a pair of tongs, to the round end of the harmonic balancer.
08. Place a block of wood on top of the repair sleeve. Hammer until the block of wood contacts the top of the harmonic balancer—then the sleeve has just sunk below the steel end of the balancer.
09. Notice how the repair sleeve fits the end of the harmonic balancer precisely and is flush to the top of the harmonic balancer.