reeco 0 Report post Posted July 22, 2009 (edited) Hi All, I'm new here and got a bit of a problem and hopefully someone can help me! Ok, I Have a 1991 BMW 318i Manual, Last couple of days its been making a knocking sound from the rear this happens every time I am letting my foot of the accelerator. I assumed it was either the C.V's or Diff. So we jacked up the car a and let it run then the knocking was coming from the centre Diff so i'm going to replace the diff, but I don't know what the diff ratio is for my car and does it makes a difference on what the diff ratio is, like if I use a diff out of the same model but auto. Any help would be appreciated! Thanks Edited July 22, 2009 by Reeco Quote Share this post Link to post Share on other sites
Livi 0 Report post Posted July 22, 2009 Make sure its your diff though ,I thought it was my diff that went when mine started knocking and there was a large humming noise ... priced up a diff etc , and went to the bmw parts place and turned out they were my two back rear wheel bearings. hope you get it fixed! Quote Share this post Link to post Share on other sites
bellicose 9 Report post Posted July 22, 2009 Well you could fix it but won't last long with ya car THAT low. Quote Share this post Link to post Share on other sites
Livi 0 Report post Posted July 22, 2009 my car is that low has been for over 5 months now and my diff is fine? Quote Share this post Link to post Share on other sites
reeco 0 Report post Posted July 22, 2009 Well you could fix it but won't last long with ya car THAT low.I've raised it up. but thats beside the point. Quote Share this post Link to post Share on other sites
Mark 178 Report post Posted July 22, 2009 May not be your diff... could be the guibo or flex disc, the part that connects the driveline to the tranny. May I also suggest that it could be your rear shock mounts (exacerbated by the ride height of the car). Get it checked properly before you start replacing stuff on a hunch. Quote Share this post Link to post Share on other sites
bellicose 9 Report post Posted July 22, 2009 I've raised it up. but thats beside the point. It's not beside the point if you think 'bout the stress you put on all the suspension parts when it's that low, think about it. Quote Share this post Link to post Share on other sites
reeco 0 Report post Posted July 22, 2009 my car is that low has been for over 5 months now and my diff is fine? Thanks Livi lol. Quote Share this post Link to post Share on other sites
reeco 0 Report post Posted July 22, 2009 May not be your diff... could be the guibo or flex disc, the part that connects the driveline to the tranny. May I also suggest that it could be your rear shock mounts (exacerbated by the ride height of the car). Get it checked properly before you start replacing stuff on a hunch. My mate who is a mechanic raised the car let it run and the noise is coming from the centre of the diff. Quote Share this post Link to post Share on other sites
BM WORLD 1261 Report post Posted July 22, 2009 check the tag at the rear of the diff. also need to know if its a small or mediuam case . mostly likly will be small and be a 3.64 ratio Quote Share this post Link to post Share on other sites
reeco 0 Report post Posted July 22, 2009 It's not beside the point if you think 'bout the stress you put on all the suspension parts when it's that low, think about it.Yeah ok mate look I wanting to know about the diff I don't want your opinion about how low it is. Its my choice, so if your not going to help me solve the problem then don't bug me on how low my car is. Quote Share this post Link to post Share on other sites
reeco 0 Report post Posted July 22, 2009 check the tag at the rear of the diff. also need to know if its a small or mediuam case . mostly likly will be small and be a 3.64 ratio I had a look all over the diff and we couldn't find anything the only numbers on it where like 000-40 or 060-40 were quite hard to read. Quote Share this post Link to post Share on other sites
