synchros

[Damianplausa]

i got a 87 325is when ever i drive and down shift from 4th to 3rd gear it grinds pretty bad sometimes it does it when i go from 2nd to 3rd but only sometimes, i think its my synchros but not sure im new to this stuff n trying to get into bmws just bought a 87 325is n i love it but the transmission is giving me that problem any 1 got some clues or ideas or tips how i can fix this. thx

[jlevie]

The first actions should be to replace the motor and transmission mounts, rebuild the shifter and change the transmission fluid. If the problem is still present replace the transmission.

[yeaseth]

I have a similar problem with my 1st to 2nd but I just end up shifting in the 3500rpm range and the ratios match up pretty good for it to go into gear. Would royal purple help? I changed my fluid out to lucus non synthetic oil about 6 months ago