We had a 1984 300TDt whose rear axle gave way without any warning. I suppose that the boot had been leaking and the CV joint dried out, then it just exploded while underway at speed. Quite a mess, and the car needed to be flat-bedded to the repair shop.

I would replace it if he says it's necessary. You can use a rebuilt axle to save some money, but definitely get it done.

Best Regards,
Rob

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Robert Fini

'12 ML350 BlueTec, 111k
'06 E320CDI (x2)
'05 T1N Sprinter 2500/Pleasure-Way Plateau TS, 72k
'97 C36AMG, 325k (son's)
'94 E320T, 249k
'93 190E Sportline LE, 168k (daughter's)
'84 190E-2.3/5spd (Stage Rally Racer)
'66 230 W110 Sedan (Barn Find, Vintage Racer build in progress)