A bearing puller tool is an essential repair aid when working on an engine or machine that has pressure-set bearings in its mechanisms. Without the tool, repair of bad bearings would be very difficult and prone to a high risk of damage to the engine.
How Bearings are Installed
Pressure-set bearings are installed into engines or machines with a high amount of pressure. This is usually applied by a hammer, a drill press or leverage. The bearing itself has to sit tight inside the engine or machine case to work properly. If it were loose, then the outer case of the bearing would spin along with the inside part connected to another engine part. The result would be damaging wear and an explosive failure while the engine is running.
How the Tool Works
Bearing pullers, depending on their design, can actually be used to both install or remove bearings from an engine casing or machine cavity. The concept is simple: Have one part of the puller press against the casing while an inner part pulls the bearing out or into its socket. By applying the pressure evenly without an impact, the puller transitions the bearing without any damage being done to the casing that holds it.
Some pullers use hook arms to hold onto a bearing while pulling it off an axle part. Again, this approach uses slow leverage to affect the movement rather than brute force.
Can a Bearing Be Installed/Removed Without a Puller?
Yes. Generally, the old bearing is popped out with a metal punch or socket piece. The punch is the same diameter of the bearing or slightly smaller to make sure it clears the casing cavity. Then a hammer is applied and the bearing is knocked out of the case. The risk, however, is that the hammer misses the punch or it jumps on impact and dings the casing. Because many engine cases and machinery are made of aluminium to reduce heat and save on weight, a metal punch with one hit can cause a lot of damage.
Installation works the same way with brute force and an even higher probability of error with a missed hit.
Where Can I Get a Bearing Puller?
A given bearing puller doesn't work for every bearing and engine. You need to make sure you research and identify the proper puller tool for your engine or machine. Your engine or machine manufacturer should have this information on reference either by calling them or getting the repair manual for the engine or machine.
Once you know the specific tool, you can usually find it through your auto parts dealer. Since pullers are not always in high demand, you may need to order it and wait for delivery. You can also search on the Internet for suppliers or try to find a used puller on eBay or on a classified ad website.
Are Pullers Expensive?
Cost depends on how much demand there is for the tool. Some bearing pullers are common and you can find them stocked at a reasonable price at an auto parts dealer. Some are very specialised and can cost hundreds of dollars to secure. You would have to go through specialised ordering to get these types of tools.