Steering......Violent!

Heading to work this am in 200tdi 110. Trucking along at 40-50mph and went over slight/gentle depression in road. Well it sent the steering wheel crazy and I thought I was going to lose it. Like an alignment speed wobble but way worse. I slowed right down before I ended up in the curb and thought about whether to go on. I heard no bang, bump or alarming knocks and car settled down for rest of journey- only about another 1km at 30mph.
Got her home too without any issue but nervous now.
Only recent job was alternator belt tighten and power aspect of steering has been possibly a little tighter since but no big difference.
Slight depression in road to load/unload suspension should not have done it I don't think.
I need vehicle over weekend so any quick thoughts.
Thanks

I assume that deflection on the alt belt was set at about 4-5mm? Although if its over tightened I can't see why it would make a great deal of difference. I think you're looking at the physical components of the steering rather than the belt or pump.

I am drunk however so.......y'know, maybe tell me to be quiet

Check panard rod bushes for play

Once you have experienced it, you know very well why they call it "Death Wobble".

+1
It's an experience alright
You'll not mistake it for anything else

May sound silly but have you checked your tyre pressures.

I'd go check pal hard rod bushes aswell, pry bar needed

Check steering damper

Pan hard rod bushes! Search "Death wobble".