I'm trying to remove the drive seal from my Sierra diff but it ain't budging. Tried screwdriver etc first to no avail and now got the proper tool. It won't budge even with that. Even that with a foot of exhaust pipe on the end it won't budge. Like it's glued or something! Also tried heat gun to soften the rubber but still nothing. I'm almost levering the car off the axle stands!

Any tips of the trade I can try?

Managed to rip through the front metal face now but still not budging. If it does that a couple more times there'll be nothing to get purchase on!

Doesn't look this hard in the videos - there isn't a retainer of some sort that I'm missing is there??? Can't see one but there's something wrong here...

Knock a sharp spike though the side of the seal and then lever it up against the side of the housing it will come out.

Had to deform the seal by forcing a screwdriver down the outside of the seal but it came out eventually! Thankfully managed to avoid damaging the machined surface where the new seal sits.

Maybe next time I'll replace it when it definitely needs doing, rather than just doing it as a precaution whilst the drive shaft is out