904 Transmission Stopped Going Into Gear

I only replace bushings that are bad. That pump bushing looked pretty good to me; a lot of them show copper when new. The drum bushing looked worn, but also check the pump cover surface where that bushing rides and replace the pump cover is there's wear. Check the inside of the pump cover for wear from the forward rings. Also check the inside of the direct drum for wear from the direct rings. Any wear; replace the drum. Replace that converter. It looks worn in the bushing area and it might be grooved in the seal area. Check it for cracks emanating from the square cuts toward the front. If you stick your finger inside you'll find the weak spot of the 904; the converters are thinner forward from the pump tangs and that's what makes them crack. You can tap it and oil will come out of the crack; then you can see it. Bottom line, although the filter will protect the valve body and converter from contamination by large particles, the problem arises when new hot fluid hits the built up layers of contamination that have been compacted into the outer perimeter of the converter. While all of this has been a build up of very fine particles that can't damage much, it gets washed out in large compacted chunks that will clog your new filter again and again. Rebuilt converters aren't hard to find. If the composite thrust washers are brittle then replace them. Put a new on on the front of the output shaft. You can put two on the pump to reduce endplay.