I don't know if that has any relevance though... it would cause the gears to crunch when you select them, but they should still select.GL-5 is not necessarily backward-compatible in synchro-mesh transmissions which are designed for a GL-4 oil: GL-5 has a lower coefficient of friction due to the higher concentration of EP additives over GL-4, and thus synchros can not engage as effectively. Also, transmissions which explicitly call for GL-4 oil may have been designed around this lower concentration of EP additives and thus may contain yellow metal parts which GL-5 will corrode.
As said on the phone...are you sure the clutch is not dragging...going in to gear stiff can be syncro...coming out of gear is not syncro...could also be a gearbox that has been run out of oil before and gears are partially seized on the shafts.[/
already checked that thanks, no sign of clutch drag and can select reverse straight from first with car running , as said 5th and reverse are no problem even 1st and 2nd are not too bad but 3rd and 4th are an absolute nightmare. Thanks