Gear diff for DEX210 too wide!

[Kusal]

Anybody had the same issue?
When measuring the inside distance between bearing to bearing on the diff is 19.2 mm for the ball diff while for the gear diff it is 19.8 mm; result the gear diff is too wide and does not fit in the gearbox!
Any idea what to do? Leave the seals out (which is to me not done but who knows) or do I have a gear from the 1st generation.
If yes, where can I order the correct gear from?
Thanks for the help!
Anyway back to the ball diff for the moment.