Had been noticing a gradually (over a few months) increasing vibration and wobble in the front end of my 85 300D. Figured it was probably an out of balance tire, or perhaps a warped rotor. Finally got around to it this weekend, pulled the wheel and loosened the caliper bolts and the whole rotor assembly had 1/2"+ play. Popped the dust cap and the allen C-clamp nut or keeper was within a thread of being in the dust cap. Immediately checked the other side, as both front wheel bearings were replaced at the same time, along with the UCA's and tie-rods and lower ball joints last fall, it was just as I had left it.

The vibration isn't completely gone, but I drove the car close to 900 miles after tightening everything back up and replacing the brake pads and its manageable. I don't know what would've happened if the keeper would've come off while going 75 mph down the interstates.

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1985 300D Gretchen (Astral Silver) 220k
1983 240D 4-speed Evelyn (Orient Red) 203k


TANSTAAFL

Perhaps you've got a wheel/tire that's lost its wheel weight and the imbalance over time has been enough vibration to loosen everything?

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-James

'85 280GE...sold
'96 Impala SS ~ 6-speed 396
'14 Cadillac Vagon. . . . . . . . . . "Life without knowledge is death in disguise." - Hans-Peter Geerdes

was it the drivers side? because the way the wheel turns, this side is more likely to loosen.

glad everything is good so far. I reckon you should replace bearings. they would have worn wrong.

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1984 123.193 372,xxx miles, room for Seven.

1999 Dodge Durango Cummins 4BTAA 47RE 5k lb 4x4 getting 25+mpgs, room for Seven.

The right front wheel bearing losened up like that on my SDL, although only by one thread. It was just lose enough that when I braked going slow I could feel a bit of a vibration coming from that corner. Jacked the car up and sure enough the wheel had some play.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

yes, driver's side. I was thinking the same thing about replacing the bearings, hopefully most of the continuing vibration I'm feeling will be cured by that. I also have an axle replacement on the horizon because alot of what I feel seems to be in the seat of my pants not the steering wheel. The only reason I didn't check after doing the bearings was that I had the benz dealership check the run-out when they did the front end alignment. Live and learn.

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1985 300D Gretchen (Astral Silver) 220k
1983 240D 4-speed Evelyn (Orient Red) 203k


TANSTAAFL

If that clamp nut comes off then the whole wheel/hub can go flying off the vehicle! Pretty scary! I just repaired the same issue on our 300D....either the last person to work on it didn't tighten it right to begin with, or just left too much play in it, because the bearings were toasted and the end nut was about 3/4 turn too loose, allowing way too much play in the bearings.

The FSM calls to tighten it until the wheel is "difficult to turn" then back it off 1/3 turn. Its a pretty snug fit.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Not as long as the brake caliper is intact.

Hmmmm....if it really started wobbling or if the outer bearing fell out as well (which it easily and likely would) that would start a pretty violent vibration and wobble.....or the wheel could jam....it'd not be pretty.....I bet it would shatter the rotor and then the wheel would come off, especially if it happened at high speed.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Well you shouldn't let it get that bad.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Yes.....I certainly wouldn't, but there's plenty of people out there that would! I've seen people going down the road with flat tires, wheels wobbling around from getting bent real bad.....things dragging on the ground under the car....the list goes on. In MI, there are no vehicle inspections, so there's some pretty interesting crap rolling around out there.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)