I haven't noticed any slop in the steering box of my 205K mile 190E Sportline, though my 190D with 320k miles on it did have a tiny bit of slop. The W123 boxes seem to wear out much quicker, I wouldn't be worried about these being worn out, but it may be worth hooking it up with the engine running but it not in place to see if it leaks or to just reseal it anyway. They aren't incredibly difficult to remove, biggest pain it the tie rods so having a Mercedes style separator would probably prove to be very useful.

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Current: 1975 450SEL, 83 300D, 88 Yugo GVX, 90 300D OM603 swap, 91 F150 4.6 4v swap, 93 190E Sportline LE 3.0L M104 swap, 93 190E Sportline LE Megasquirt, 03 Sprinter, 06 E500 4Matic wagon.