The weakest link on any starter is the POSITIVE contact. This is the part that takes all the amps at start up. I have many times just replaced this contact, under the bolt, and starter continues to work. Clean it up, blow it out, wipe it off, rebuilt starter... :0) I get the copper contacts from a rebuilder, couple bucks. Otherwise I buy from AutoZone, lifetime warranty, they keep your phone # in their data bank, so no worries to keep receipt. Their duracraft brand is decent...I haven't had any issues. Diesel starters are tough!