85 300D whirring noise/transmission Q

[Ya Mar]

Hello everyone,

My 1985 300D when driving from a cold start makes a loud whirring noise for the first 5-10 minutes. The pitch of the noise is in concert with the speed of the car. It gets higher as the vehicle moves faster. The noise comes from the front of the car. It's rather obnoxious and I'd like to repair the problem. Any ideas?

Note:
1) I have a manual transmission and I can hear the noise regardless of being in gear or in neutral.
2) I can hear the noise regardless of whether the interior fan is blowing or not.
3) When the noise stops, it is completely gone, it doesn't fade out, it just stops abruptly. But it takes 5-10 minutes.


Another question I have is regarding changing the manual transmission fluid:
1) What fluid should I replace it with?
2) Is there a filter in the manual transmission that needs to be changed? I've only found auto transmission filters at parts stores. The car is a 4spd manual.


Thanks!