M30 Transmission

The M30 transmission is a variation of the venerable 4L60E transmission, and is manufactured by General Motors.  It has four forward gears, the third of which is a 30% overdrive.  M30 itself is a RPO code.  It stands for: M30:   TRANSMISSION, AUTO 4 SPD, HMD, 4L60E, ELECTRONIC There is a different RPO code for every … Read more

GMPT 4L60E

  The GMPT 4L60E is a GM automatic transmission.  Some 4L60E’s will have this stamped on the case, usually on the bellhousing portion.  The GMPT itself stands for General Motors Powertrain.  It’s similar to the way that MD8 was stamped onto the 700R4. GMPT Folklore. Many enthusiasts see this stamp on the case and get … Read more

How to tell if you have a bad neutral safety switch

Back in the day, when you’d go to start a car it would be entirely possible for you to bump the starter and have the vehicle just take off.  This would cause damage to property, other vehicles, and even human life.  The Neutral Safety Switch was invented to curtail this issue.  The neutral safety switch … Read more