Just took my 300E to two shops today for diagnosis for a clicking sound my 300E makes when going in reverse (no slippage and car drives perfect in forward gears). 1st mechanix told me it is a gear in the transmission and needs overhaul ($$$). He also told me the drive shaft needes replaced for the hard shifts it makes ($$$). He had just driven it forward and backward in the parking lot. 2nd place did the same but put it up on the lift and looked for noise underneath. He thought it was muffler at first but then noticed the coupler from the transmission to the drive shaft was worn out and the bolts were very loose in the holes (you could move the driveshaft up and down easily with your hand). He told me that he was 100% sure that was the problem and that the reverse torque was causing different pressure in reverse and that the bolts were clicking because of the play (but no click in forward gears). New coupler 175.00 + labor. Also need a small bushing to steady shifter due to wearing out and now missing (play in gear shifter). I guess I want to know if anyone thinks that would cause the clicking sound when in reverse (no sound when in neutral and coasting backwards) or has anyone ever heard of this? It's a rythmic clicking noise that occurs fairly rapidly and sounds like it could be a gear as it matches speed of car rolling backwards. Thanks
Aug 22, 2009 at 5:54 PM