What is the whinning sound coming from transmission? on 1994 BMW 540i

I have a 1994 BMW 540i with 161,000 miles on it. I hear a whining sound coming from the transmission mostly at acceleration and changing through the first two too three gears.shifting between gears is pretty much smooth. What could it be and is it serious?


Asked by for the 1994 BMW 540i
It is safest to have a repair shop familiar with BMW check out the noise or a transmission shop. Perhaps it would be a good idea to check or change the transmission oil if you haven't had it changed in the last 30,000 miles.