300E Whirring - Transmission Pump?

[MercyBenz63]

Hello all,

Vehicle: 1992 300E 3.0L AT 122k

Problem: Last night while tooling around town a loud, rpm dependent whirring noise developed. It is present in all gears including park and neutral. This morning when I started the car the noise was still present. I got my trusty stethoscope and began listening. Unfortunately, when I placed the stethoscope on the transmission dipstick tube the noise was very loud and there was a lot of high frequency vibration in the tube. The fluid is to the proper level and clean. The filter has been replaced within the last 10k.

Threw caution to the wind this morning and decided to drive the car to work. Low rpm in gear cause the noise to get louder. Other than the noise the car drove beautifully and shifted perfectly.

Questions: Has anyone had the transmission pump fail with only 122k? Did it make a whirring noise? Are there other parts of the transmission that can make this sort of noise?

Thanks in advance for your help.