Can you repair a washer that leaves mold on clothes?

Clean washer from Mold: Yes, you can try to fix a washing machine that leaves mold and mildew on clothes by cleaning it thoroughly.

Cleaning With Vinegar or diluted bleach solution:

You can start by running the machine empty with a cleaning solution like bleach or vinegar, and then you can wipe down the washer drum and other accessible areas.
If it is a front-load washer, clean the rubber gasket. You can pull back the rubber seal carefully and wipe with a cloth soaked in vinegar and water or a diluted bleach solution.
Follow up with another empty hot wash using half a cup of baking soda to neutralize odors.

Cleaning With a commercial machine cleaner:

You can choose to use a commercial washing machine cleaner like Affresh or Tide Washer Cleaner instead of vinegar.
You can also try to run the longest hottest cycle (use clean washer mode if available)
Always wipe the drum, gasket (also called door seal) and the detergent tray with vinegar-soaked cloth afterward.
Rubber door gasket is known to harbor mold. It can either be cleaned or replaced in some instances
Drain the pump filter if the washer has one and try and clean it on a monthly basis

How to Avoid Mold and Mildew:

Always leave the washer door open to dry moisture out
Do not use too much detergent as excess of soap can trap dirt and breed bacteria.
Check your water supply hoses for leaks or stagnant water.
Dry the washer after each use.
If the mold is persistent, you might consider calling a professional appliance repair.