I have about 40k on my rebuilt trans, recently it has gotten hard to get into 1st or 2nd gear at a stop sign or redlight (you have to go into 4th or 5th then back to 1st) and sometimes after rolling it wont go into 3rd or 4th without pushing it in. I installed a new clutch master cylinder (nonadjustable) last year but that didnt help. I also changed the Amsoil out about 4k ago. Didnt do anything either. Do you think a HD Mastercylinder is needed or do I have some synchros goini out? I run a Valair ceramic clutch. Thanks for any input

 

The only oil that I am sure is for the NV5600 is Mopar and Pensoil Syncromesh. The Pensoil is all I have used and it still shifts like new.