I also have a 1986 MB 560sl with 120k. Last week I have changed the steering coupling, idler arm repair kit and sterring pump filter. The steering is crisp and easy. Feels very nice almost like new. The steering fluid level is ok also the belt is new but I have a strange sterring whoom noise.

I had this noise before when I had a steering hose leak and not enought of fluid...as soon as I added fluid changed hose there were no whoom noise while steering. This was the case before I did above mentioned repairs.

Does anyone no what would be the culpit in this case since everything is new and there is enough fluid and no leaks but still I have the whoom noise while steering?

Thank you all for any input.

Balsa