The Delco 39MT Series PLGR Starters replace many older model 42MT, as well as 40MT Series DD. One of the features of the 39MT is an electrical soft start, which reduces drive and ring gear wear. The following video from Delco Remy illustrates this feature.
Take a look at the 39MT units and service parts we have available in our store, or feel free to contact us with questions.