I have never seen the Pilot Bearing on a Mercedes and don't know if it is a Needle Bearing, other type of Bearing or the mentioned Bronze Bushing. So I will speak in general.

I suppose it is possible to damage any of them during installation and when sticking the Transmission in.

I have dinged up the Bronze Bushing typed during Transmission installation before so I know that is possible.

The Needle Bearings generally need to be lubed before you install them. Other types of Bearings if they are from China or some place that makes similar quality Bearings I always suspect the Grease inside of them and if I can I pry off one of the Shields and take a look. If I don't like what I see I remove that Grease and fill it with Wheel Bearing Grease.

If there is an issue with the Transmission Input Shaft Bearing it will take out the Pilot Bearing. Of course a bent Input Shaft will cause issues.

If a Bronze Bushing is used it needs to be made of the Oil Impregnated type of material.

If it is a Ball Bearing type Pilot Bearing part of the idea of that is that it does not wear the end of the Input Shaft like a Bronze or Needle Bearing does.

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84 300D, 82 Volvo 244Gl Diesel