Mckay DN 86 Stitcher Problems

[JFlo]

I have been stitching with the DN86 for years.    The whirl and pinion was changed approximately two months ago and recently the horn began to violently turn with each down stroke of the awl.   It appears to be conflict between the whirl  and pinion.    Manually turning the machine will almost make a revolution, but binds also.   If I remove the whirl and pinion, the machine is free flowing with no hiccups.    I ordered a new pinion and whirl for the just in case scenario.   When the parts arrived and placed in the machine,  it too, binds the machine.   Is there anyone else who has had this problem?    Any suggestions on how to remedy this dilemma and get this stitcher up and running again would be greatly appreciated.

[Northmount]

@JFlo moved your post to leather sewing machines.