Oily bottom end
I had planned to replace the harmonic balancer with an ATI underdrive unit, but it was simply too expensive after adding shipping costs and 25% VAT. I decided on an OEM PB1117N Dayco balancer.
Ouch, what a mess
I found non-factory sealant between the front cover edge and the oil pan, so someone has previously serviced the engine. They obviously didn't care about centering the front cover and seal, which resulted in uneven wear of the seal, which again wore down the sealing surfaces of the harmonic balancer.
To avoid a revisit later on, I decided to change all other parts that could be causing an oil or water leak in this area. Front cover gasket, water pump gaskets, front end seal. The lower oil pan gasket was changed last year.
Removing and reinstalling harmonic balancer
The first attempt at removing the balancer failed. I retried with a stronger puller with a sharp end tip, which would secure itself securely in center of the bolt. I also preheated the pulley with a heat gun for 5 minutes. It would then pull of like in butter.
The front cover and gasket was centered using the Mr Gasket tool LSTC1.
Rather than buying an expensive balancer install tool, I purchased a M10 threaded rod, some solid nuts and washers.
The new balancer was preheated in the oven for 10 minutes, and with assembly lube between the washers the new balancer went smoothly on.