Chevy S10 4wd Vacuum Actuator Repair Ring

thingiverse

This is a set of custom printed parts designed to repair and upgrade the 4wd vacuum actuator on S10s for locking the front differential. The OEM part lasted for years, but eventually wore out, leading me to design replacement parts that can be rebuilt with a piece of thin rubber or silicone. Every aftermarket part I've tried has failed within a year due to deteriorating rubber. There are three main components: two large clamping rings and the spring plate (which is optional). You'll only need two of them for basic functionality. I started by disassembling the old actuator, prying off the aluminum crimped ring with a screwdriver and cutting pliers. Once removed, unscrew the cable holder from the aluminum plate to remove the worn-out rubber. Mark the center of your new material, punch or cut a hole for the bolt, and attach it to the housing. I'm currently testing a piece of bicycle tire inner tube but have not decided on a permanent material yet. For assembly, you may need help from a friend or some clamps to center the new "boot" and measure its height. The actuator's top must be high enough to connect to the cable without putting tension on it. When vacuum is applied during 4wd, the actuator will suck in the boot and pull on the cable, while the spring helps release the cable back to its normal position when 4wd is off. I've not measured this height yet, but you'll want to ensure the cable has slack when reinstalling. One of the rings features a step that allows the actuator housing to sit flush within it. Your new "boot" will be sandwiched between the stepped ring and backup ring. The holes are sized to thread an M3 screw snugly with at least 20mm length, accommodating a nut on the end or additional washers for better sealing. Using screws alone won't completely seal the rubber between clamping rings; I tried it and experienced slight leaks. Adding nuts and washers resolves this issue, making it airtight. If you choose to print the spring plate, be aware you may need to adjust the bolt length to accommodate its thickness. The only advantage of the spring plate is the pocket that holds the spring in place without movement during operation or assembly. I hope you find these custom parts useful; feel free to ask questions or leave comments if anything isn't clear.