I own a California-version 1976 2002 with 23,000 miles and would greatly appreciate any advice as to what may be causing a rattling, bearing-like noise in the transmission. It occurs in any gear only when the clutch is engaged and mainly while lightly "feathering" the throttle (as when maintaining a specific speed). The noise disappears immediately when the engine is placed under load (moderate to hard acceleration) or when the clutch is depressed. The rattling started at around 15,000 miles but now approaches a "growling" intensity. My local dealer diagnosed the problem as defective transmission bearings. They subsequently replaced all four transmission bearings for $300, but to my despair, the condition remained unchanged (one bearing was slightly rough upon spinning). The clutch has also been replaced. The dealer and his transmission mechanic admit that something is wrong but that they themselves don't know the solution. They suggested that I will probably need a new transmission!! I cannot understand this logic at all since it shifts with no problem and there is no grinding
Author: Laurence S. Wong
In 1976 BMW changed the design of the transmission pilot bearing from a ball to a roller bearing although the ball bearing design had worked satisfactorily on all standard transmission models from 1964 to 1975. The symptoms described indicate a bearing which is in the process of failing. The earlier ball bearing was packed with grease and then covered with a felt patch which fit snugly on the transmission input shaft. This patch held the grease in the bearing. The later roller bearing was also packed with grease but has no device for retaining the grease. It has been my experience that failure after 50,000 miles is not uncommon.
Author: Tech Ed.