Oil Leak

I have a 99 Grand Prix GT 3800 with 145k miles on it. It has recently develope a small oil leak from what appears to be the front end of the engine. After inspection I found that the front u-shaped engine mount was full of oil. I suspect that the oil seal for the crankshaft in the engine front cover has failed. Is this common? Also it appears that I can access this through the wheel well on the passanger side. It seems that this should not be to difficult to replace, but any advice up front would be greatly appreciated.

Thanks

It happens but not really that common. Best to remove the crank pulley and harmonic balancer like doing a crank position sensor job and do a closer inspection just to be sure. The seal on the timing chain cover actually contacts the harmonic balancer. See pic below.

http://mykidz.net/GTP/Images/CrankPosSensor/images/RemoveSencor_JPG.jpg