Replacing an alternator pulley can often be done without removing the entire alternator from your vehicle, saving you significant time and effort. However, this task requires specialized tools that aren’t commonly available for purchase – until now! While pre-made tools are becoming more accessible, crafting your own Car Alternator Tools remains a cost-effective and resourceful solution for many DIY mechanics. This guide, as a follow-up to our alternator removal post, will walk you through creating your own pulley removal tool and using it to replace your alternator pulley while it’s still in the car.
Firstly, you’ll need a spline tool designed to hold the alternator shaft while you loosen the pulley. A readily available option is the Metalnerd spline tool, which you can find at Metalnerd.com.
In addition to the spline tool, you’ll require a 12-point bit that fits inside the spline tool to engage with the pulley. A 10mm 12-point or triple square bit is typically suitable. These bits are widely available; you can often find sets of various sizes at good tool stores or purchase individual bits from brands like Snap-On. Lisle set 60750 is a popular and affordable option, easily found with a quick Google search.
Once you have your 12-point bit, the next step is to modify it to fit within the spline tool. This involves grinding down the hexagonal base of the bit so it can slide snugly inside the spline tool. A bench grinder is ideal for this task.
During the grinding process, ensure you don’t remove too much material. You still need a portion of the hex base remaining so you can grip it with a wrench later on. Test the fit frequently as you grind to avoid over-grinding.
It’s crucial to get the length of the modified bit right. Limited space in the engine compartment between the pulley and the vehicle’s frame demands a precise tool length. If possible, having a spare alternator on hand to take measurements from is highly beneficial. In most cases, trimming about half an inch off the end of the bit should provide the necessary clearance.
With your DIY car alternator tools now crafted, you’re ready to tackle the pulley replacement. Start by accessing the alternator area under your car. Removing the side splash guard and the serpentine belt is essential for clear access to the alternator pulley. Use a screwdriver to carefully pry off the protective plastic cap covering the pulley. This will expose the center where you’ll insert your newly made tools.
Now, insert your assembled car alternator tools into the pulley. You’ll need two wrenches for the removal process: a 17mm wrench to turn the pulley itself and a 1/2″ wrench to hold the modified 12-point bit, preventing the alternator shaft from rotating.
To loosen the pulley, turn the 17mm wrench counter-clockwise, just as you would loosen a standard bolt. To keep the alternator shaft stationary, you can utilize the vehicle’s frame rail to brace the 1/2″ wrench. Position the 1/2″ wrench against the frame rail for leverage while you apply force to the 17mm wrench, pulling it towards the front of the car to loosen the pulley.
Installation is essentially the reverse of removal. To tighten the new pulley, again use the 17mm wrench on the pulley and the 1/2″ wrench on your modified bit. This time, you’ll turn the 17mm wrench clockwise. For leverage during tightening, you can use the harmonic balancer to hold the 1/2″ wrench steady while you apply torque to the 17mm wrench, pulling it towards the back of the car.
Finally, remember to re-install the dust cap onto the new pulley for protection. The entire pulley swap, once the tool is prepared, should take around 20 minutes, with an additional 10-15 minutes for tool fabrication. If you need to remove the side skirt, factor in a bit more time.
This DIY approach to creating car alternator tools and replacing your pulley in-situ is a practical solution for addressing common alternator pulley failures. While my original pulley was still functional, preemptive replacement during a tensioner change is a smart preventative measure. Addressing potential issues like a failing pulley in a controlled environment, like your driveway, is always preferable to roadside breakdowns, especially in adverse weather conditions.
