Saginaw 4 Speed Identification

The Saginaw four speed transmission is a transmission that was used in a variety of GM cars in the 60’s. They were popular in the Muscle Car era. As a rule of thumb, they were not built to handle the kind of power that a Muncie transmission could handle. So, if you are looking to … Read more

Clutch Replacement Cost

Clutches are similar to brake pads in many ways.  They are made of the same type of material, and they both wear out eventually.  The good news is that although a clutch replacement costs more than a lot of vehicular repairs, it is nowhere near as expensive as having an automatic transmission rebuilt. The number one … Read more

Finding a Good Clutch Repair Shop

I was listening to an episode of Carcast with Adam Carolla one time.  I believe he was talking about finding the right guy to repair a dent in his car.  He said something along the lines of you don’t want a guy named Ashton touching this thing.  You want an old guy with a name like Duke or … Read more

4L80E Transmission Problems  

The 4L80E Transmission is a fully computer controlled transmission that comes bolted to the higher horsepower and torque trucks.  It is the overdrive successor to the 3L80(better known as the TH400 for most of it’s life).  It is significantly larger than the 4L60E and if you compare the cases side by side it makes the … Read more

Allison Transmission Problems

This short guide is will hopefully help you diagnose simpler Allison Transmission problems. Allison Transmissions have been around for a hundred years and have set the industry standard for durability.  The odds are pretty good that you’ll never find your way here, but if you did lets get this figured out!   Limp Mode on … Read more

Difference between 4L60E and 4L65E Transmission

What are the major differences between the 4L60E and 4L65E transmissions?  If there were a one-word answer to this question it would be strength.  The 4L65E is manufactured to handle more torque than its counterpart.  They have an identical looking case.  For all intents and purposes the 4L60E became the 4L65E when GM upgraded some … Read more

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


  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