Special Tools – Are they necessary?



Virtually every engine manufacturer in the world offers special tools for sale with the engines they make, and MarineDiesel is no exception. In fact, on large projects and government tenders, there is usually a requirement specified to add in to any quotes all special tools that may be required to perform service.

What is the purpose of these tools?

Are they really necessary?

Sometimes, they can get fairly expensive. Why?

The answers to these questions may not seem so obvious at first glance.

When engines need service, it is oftentimes not easy to access, or install, or remove, various components. Indeed, the MarineDiesel manuals for our VGT Series of engines run to over 500 pages if combined. Add in the various manuals for accessories, options, etc., and you have quite a large binder of information.

First off, there are maintenance and repair procedures that only factory trained service technicians should perform. These are often complicated, or require specialized facilities or heavy equipment to perform. When most of our dealers undergo their factory training, they usually purchase one or more sets of special tools. The purpose of these tools is related to many factors:

  • The specialized requirements of the engine. (Say, a special bolt needs to be manufactured for torque resistance.)
  • Design requirements. (For instance, a cover or plate needs a specific shape.)
  • Access to components. (Parts are located inside other parts, or are located in places that are difficult to reach with standard mechanics’ tools.)

On MarineDiesel engines, none of the special tools is an absolute necessity: All maintenance can be performed in a well-equipped shop. The special tools can, however, allow maintenance and service jobs to be completed more quickly and in an easier manner.

Are they expensive? Not really. However, they are specialized to a specific function, and they are more expensive than a standard, similar-sized tool. This is because the market is very limited. A manufacturer of wrenches may make a million of a standard wrench. Design the tool, and tool the machinery once, and get millions of finished products. Special tools may only be manufactured in the hundreds. We are cognizant of this fact, and strive to eliminate all necessary special tools (How often have you bought something that requires some weird wrench to assemble? Talking to you, Chinese bicycle maker!) The special tools we sell are merely designed to make service easier: Nothing more.

Here’s the complete, short list for our VGT Series of engines:

  1. Injector pullerMD44639 – Injector puller – Ensures damage free injector removal on VGT diesel engines.
  2. oil seal installerMD41221A – Oil seal installer – Consists of six tools designed to install the front and rear crankshaft seals.
  3. flywheel holderMD44643 – Flywheel holder – Used to hold the flywheel/engine stationary during removal of hub bolts
  4. rear crankshaft seal removerMD44641 – Rear crankshaft seal remover – The rear seal is press fitted to both the engine block and crankshaft, this is a special puller with three jaws to grab the inner lip of the seal. The forcing screw attached to the center plate is used to react against the crankshaft end to pull the seal out.
  5. HD Compression Test KitMD23223 – HD compression test kit
  6. specialty tool storage caseMD44648 – Specialty tools storage case