Dynojet Snowmobile Dynos: Installation Guide - Manual (Page 27)

Document # 98260100 3-9
Step 9
The track should be hanging loose at this point,
you will need to pre-tension the track with the
Driver Carriage.
Loosen the bolts that hold the rear mount on the
Driver Carriage.
Loosen (6) Bolts
(3 on each side)