bmw4life 0 Report post Posted July 21, 2009 Hey i own a f/l 325 with 5-speed . When changeing gears quickly a rough thump can be heard comming from around rear of car. has been suggested to me that issue is result of top rear differential bush rubber becoming soft, I have inspected underneith of car regually and cannot find anything that is obviously worn ?. any comments or suggestions?. Quote Share this post Link to post Share on other sites
Forrest 35 Report post Posted July 21, 2009 Driveshaft Hanger Bush and Bearing need replacing, I have one I can sell to you, was only in my car three weeks before writing it off. Can send you some pics if your keen, brought it off out forum sponsor Gavin at Euro Italian Quote Share this post Link to post Share on other sites
bmw4life 0 Report post Posted July 22, 2009 Hey thanks for the offer but no thanks. have inspected hanger bush for movement and there is none which as you suggest would create knocking sound. Quote Share this post Link to post Share on other sites
QuickSilver 0 Report post Posted July 22, 2009 Could be : Diff hanger bush, diff mounting bolts loose, drive shaft to diff bolts loose, centre hanger and bearing. Wheel coming off? Quote Share this post Link to post Share on other sites
tibbs.james 1 Report post Posted July 22, 2009 Engine And G Box Mounts, if they look soft torn or "all bent out'a shape" get new GENUINE ones or a custom / aftermarket replacement. Do the New Center hanger bush anyway... you might be surprised what looks alright under the car is actually S**T and full of cracks. Quote Share this post Link to post Share on other sites
Guest FrantiC Report post Posted July 22, 2009 Check diff bolts, When the come loose it does cause the exact issue you are describing. I get the exact same thing. But bolts coming loose is also a related issue to a worn diff bushing which sags the diff. Quote Share this post Link to post Share on other sites
