The Ins and Outs of Pressing Piston Pins and Bushings

We’ve spent the past few weeks talking about measuring and machining connecting rods but we may have put the cart before the horse. This week we’re going to correct that by talking about removing and installing piston pins and bushings.

In order to prep your con rods for machining, you will need to have a few items. First, you’ll need a shop press. Goodson recommends when looking to add a shop press ask yourself a few questions.

1. What’s your budget?
2. What do you plan to do with the press?
   Usually when someone gets a press, they find all kinds of things to use it for. From pressing out pins and bushings to straightening pieces, etc.
3. How strong of a ram do you need?
   For pressing piston pins and bushings, you’ll need a minimum of 5 tons of pressure, but you’ll probably want to go up to 20 to 30 tons if not higher, depending on what you plan to do with it.
4. How much room do you have for a press?
   Presses are available in lots of sizes from bench-top units to large free-standing ones. Depending on what you plan to do with the press, you will also need room around the unit so keep that in mind when choosing a press.
5. What’s your power source? Is it hydraulic or air over hydraulic? Both have their advantages and disadvantages.

For pressing piston pins and bushings, you’ll need a minimum of 5 tons of pressure, In our experience, most pins should break loose at 1800 to 2200 PSI. If you’re still running into resistance at this point, you have other problems. If all you’re going to do with the press is work on con rods, you can use a bench-top model but as we said before, you’ll probably find all kinds of uses for a press.  He also added that you need be sure it is rigid and durable. Look for quality welded joints and heavy gauge metal. When deciding which press to add to your shop, you will also want to check out the machine’s warranty. Remember, a shop press is as important an investment in your business as any of the other shop machines you use.

Now that you have the press, you’ll need some fixtures and tooling with which to work. Goodson offers several units for piston pin pressing and for pressing pin bushings, particularly tapered pin bushings. We’ll look at each one separately.

Piston Pin Removal & Installation Fixture (PPE-7082)

This fixture is composed of several parts that combine to take some of the guess-work out of removing and installing interference fit piston pins. It  was designed to protect high dollar pistons from damage since the piston itself is NEVER under pressure. One of the key features is a series of support inserts that you use to keep the connecting rod aligned properly. Several standard sizes are available, plus one that is ready to be machined to your exact needs.  For a complete run down on how to use the Piston Pin Removal and Installation Fixture, check out the product instructions.

In addition to the standard instructions, Goodson Techxpert, Chris Jensen gives these key tips:

1. Use the fixture with the press plates that came with your press
2. Always select the proper insert. Be sure it fits the piston and pin properly
3. Always use Press-Fit Lube (Goodson PFL-200) during the removal and installation process
4. Verify alignment, verify alignment and verify alignment
5. The piston must float during installation
6. The rod must be centered on the pin for proper installation

One last warning that applies with all of these operations: If you run into excessive resistance, do NOT keep applying pressure. You can easily cause damage.

Universal Piston Pin Press-Out Tool (PPE-1)

A universal tool set to use with your shop press, this tool is made of high quality steel and is sized to work with most applications. This set is for basic removal of pins without damage to the piston. Using the Piston Pin Press-Out Tool is pretty self-explanatory, but you can check out the product instructions for more details.

As with the Piston Pin Removal and Installation Tool, always be sure to use correctly sized support fixtures, use press-fit lube and verify your alignment to avoid damage to the work piece.

Universal Tapered Pin Bushing Press Kit (TB-KIT)

One of our newer additions to this class of tooling, the Universal Tapered Pin Bushing Press Kit is designed to work on common light to medium duty diesel applications. It can be used to remove and install tapered pin bushings.

Why should a shop should invest in the Universal Tapered Pin Bushing Press Kit?

1. It’s the best tool for removal and installation for tapered connecting rod bushings up to 2″ in diameter.
2. The tool is designed to prevent piston damage during use
3. With the number of bushing drivers included in the kit, it can accommodate many sizes of tapered rods
4. Specially sized bushing drivers can be made to order
5. You never have to make-do with different methods when installing or removing tapered bushings.

For more specific information, check out the product use instructions.

As always, if you have any additional questions about these or any Goodson products, contact the Goodson Techxperts by email or call 1-800-533-8010.