Replaced seeping gear selector shaft seal.

is that for the gm auto transmission?

Yes it is.

BMW believes that rubber seal is worth $40+! WTF?! Napa has for $2.29 and O'reily tops the scale at $3.49!

All rubber is not equal, most of the Genuine BMW rubber parts are Viton. The "discount" stores rubber parts usually fails much sooner.

When my OE VCG seals started leaking at around 150k miles, I replaced with the BMW Viton gaskets ($140). I could have gotten the non-Viton gaskets for around $90 less, didn't because I don't want to re-do the job in 2yrs/40k miles.

These "bargain" seals are great for indys (car will be in every 2 yrs for same repair) and used car lots (low cost part, vehicle will be long gone when it fails).

The Genuine BMW parts can be found outside the dealer network for lower cost.

how hard is it to do that seal?

Replaced both front end links and got my four wheel drive working for the first time since I had the car. When I bought it 2 bolts from the front diff were missing and one was broken off. I drilled the broken one out and replaced the bolts. Its nice driving without hearing the clunk of the drive shaft hitting the diff every time I shift and let off the clutch.

Installed cool carbon pads with centric high carbon alloy rotors. Removed all brake parts and wire brushed everything! Brake Fluid flushed.

+1 the quality of the OE seal makes a difference and does last longer. Like you I go with the OE seals.

[QUOTE=TiAgX5;1053512]All rubber is not equal, most of the Genuine BMW rubber parts are Viton. The "discount" stores rubber parts usually fails much sooner.

When my OE VCG seals started leaking at around 150k miles, I replaced with the BMW Viton gaskets ($140). I could have gotten the non-Viton gaskets for around $90 less, didn't because I don't want to re-do the job in 2yrs/40k miles.

These "bargain" seals are great for indys (car will be in every 2 yrs for same repair) and used car lots (low cost part, vehicle will be long gone when it fails).

The Genuine BMW parts can be found outside the dealer network for lower cost.[/

For something non-critical like this I could change out yearly for the next 10 years and still be money ahead. Plus it is a GM part and has been used in their transmissions for many years. I would only use OEM gaskets for critical and internal parts but for something like this there is absolutely no good reason to pay 10+ times the price.