Hardinge DV59 CNC retrofit

I have an accuslide CNC retrofit on a DV-59 lathe and having a problem with the spindle encoder. When doing external threading, it may cut 3 or 4 passes and then have a second or two delay before it starts cutting again. Although it’s only a nuisance when threading external, however it’s a major problem when tapping.

I use a Hardinge TT releasing tap holder and around 500 RPM for tapping. When the spindle reverses, the tool not always starts retracting with spindle movement and you know what happens next.

I was wondering if the encoder can be opened up and cleaned or if there is a simple fix? Belt is tight and in good shape. If not could someone tell me the manufacture and part number for the encoder? The paper tag has long faded out and unreadable.

BTW Omniturn may use the same encoder.