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

Low Transmission Fluid Signs

Automatic Transmissions have gotten so good since they were introduced in the 1950’s.  In fact, some of them have fluid that is supposed to last for the entire life of the transmission.  This often lulls people into a false sense of security.  Many people NEVER even bother to check their fluid.  This is a huge mistake.  … Read more

Torque Converter Replacement

Replacing a torque converter is relatively easy to do. Getting to the thing is an entirely different story. There are many reasons that you may wish to replace it. Maybe your transmission is slipping? This site is geared toward the performance crowd (well a little bit), so we are will cover stall speed and torque … Read more

LS Engine Swap Transmission Guide

Are you considering doing the LS swap?  It takes a lot of work to do it right, but it’s incredibly rewarding.  I’ve done this swap and there are really two important parts to the game plan.  The first is to make sure that you have a game plan for all of the challenge areas.  Deciding what … Read more

700R4 4×4

The 700R4 is a very popular transmission in 4×4 trucks.  It is both proven and rugged.  They can be found all day long in the salvage yard at a very reasonable price.  If you are looking for one just keep in mind that the factory units are typically going to found in a Silverado or … Read more

Transmission Coolers

Many transmissions have a harder life than the manufacturer had originally intended.  Whether it has found life in a street machine, or it is in a tow truck, a transmission cooler can really help keep a transmission running better for longer.  Transmissions wear out incredibly quickly when the fluid gets over the ideal operating temperature. … Read more

What is an overdrive transmission

Before the invention of the overdrive transmission, the final gear would always be direct drive(1:1 gear ration).  So, you had to choose what you wanted out of your car.  This meant that all but the most aggressive cars came from the factory with “highway gearing”.  Highway gearing tended to be like a 2:73 axle ratio, … Read more