39MT Application Changes

Detroit Diesel 13/15/16 Applications

The number of teeth on the ring gear of the new 2016 Detroit GHG17 engines and 39MT starters has changed.
  • The ring gear on the GHG17 engine (for use on 2016) has 150 teeth and the starter has 11.
  • The ring gear on the GHG14 engine (for use on 2015 or older) has 160 teeth and the starter has 12.
39MT-Application-Changes-LabelsThe 39MT starters will be labeled with the correct engine application for quick identification. These labels will be applied to both the starter and box. The starter housing will have one of two different colored labels, and the box will have a corresponding label alongside the part number label. (Samples on the right.)


The starter for the GHG14 engine MUST NOT be used on the GHG17 engine and vice versa.
Using the incorrect starter and ring gear combination will cause significant damage and will require both to be replaced. The starter pinion is the only change in the new model compared to the previous model years, but they are not interchangeable. Mixing motor and engine parts will result in starter motor and engine ring-gear damage.

Overlay Title