Can gear slip at higher speeds because of wrong ratio differential installed

[pwuser160740487562]

I swapped n54 auto in my 320d(m47) manual E90.The car's gear kind of slips when accelerating on higher speeds nearing high rpms.
Is this because I'm still running the 320d 2.56 ratio differential ?

[pwuser160740487562]

@Xulfiqar
Can you please share some insight on this?
Have always been impressed by the knowledge you possess and how helpful it is.Would mean alot if you could help with this.

[pwuser160740487562]

Bump

[dani_kk]

Differential can not do this.
This looks like the gear has some problem.