I did one
 

I had a tear and had one changed with remanuf...from carquest for $90 I think.

I did try to inject some grease and tape it up, but it didn't last even a day....

Being on a budget, I did one, and the other one didn't look bad yet...

I don't think you will be sorry if you can swing the cost of doing both...

My philosophy is to fix what is broken. It might be years before the other one needs replacing. IN the mean time you might sell junk or wreck the car.

Tom W

Just last weekend i replaced both axles in my 240D with rebuilds that came off of my wrecked 300D. Took me only 2.5 hours, granted this was the 3rd time i had done this procedure, but i was surprised how fast it went.