Swapping the OBS headlight knob to an Express/Savana van knob to match the HVAC knobs is a clean look, but be clear on one thing before you start: this is not a direct fit. The Express/Savana headlight knob itself is cheap, but the OBS headlight switch is not. Test fit before cutting, grinding, or gluing anything.
Start with the easy one first: OBS HVAC Knob Swap Using Chevy Express and GMC Savana Knobs. Those knobs bolt right on with no modification. The headlight knob below is the next step once you’ve done the HVAC ones.
I finally got around to finishing up the Express Van headlight switch on the OBS. I used the Dorman 76834 knob, which is readily found on Amazon or at your local parts store. I went with the Chrome option to match the HVAC knobs.
Overall the swap is pretty simple to do. I believe it took me roughly 20 minutes, which also included taking pictures and measurements for future reference. I’m sure you can do this quicker than me with the help of this guide.
Watch the complete OBS headlight knob swap installation below.
It would be easiest to do this swap with the headlight switch removed, but you can in fact do it with the switch still installed in the truck. You’ll have to brace the headlight switch and bezel if you choose to do the swap with the switch still installed in the truck (like I did).
I used Linesman’s pliers to remove the old OEM knob while bracing the switch and bezel. Once the old knob is off, you’ll notice that the OBS headlight switch shaft is too long for the new Express van knob and has to be cut down. I chose to modify the shaft and cut down the knob as well. If you want the knob to sit as close to flush in the circular cutout, you will end up cutting the shaft and knob so that only 3/8" of material is left on both the headlight switch shaft and the knob. Go slow when cutting, and test fit often.
I took measurements of the shaft using a caliper and came up with .258" width. This means you’ll have to cut the sides out of the knob, so that the OBS shaft fits inside of the new knob.
I came up with 0.139" height. This is the approximate measurement of how much height to cut out of the shaft.
You’ll then want to transpose these measurements onto the headlight knob, and mark out the areas to be cut. To fit the OBS Headlight shaft onto the knob, the 0.139" height has to be measured, marked, and carefully cut out of the knob. The 0.258" width effectively means you’ll have to cut the sides out of the knob as well - but don’t worry, with clean cuts and a strong epoxy the knob will be rock solid on the switch. Below is an image of the measurements of the cuts.
You’ll also need to “shave” the knob sides flush, so that the sides fit inside of the headlight switch.
Here is a clear comparison of what you’ll start and end up with. Once again, be careful when cutting, and test fit often. I found it helpful to go slow with the cutting. The knobs themselves are cheap, but the headlight switch is not.
Once you’ve test fitted it, you can mix up your epoxy of choice. I chose to test fit it dry (without epoxy), and make sure that it still actuates the switch before mixing any epoxy.
I chose to go with JB KwikWeld which sets after about 4 minutes.
Be sure to wear gloves when mixing the epoxy, and apply to both the shaft and inside of the knob. Be sure to not get any where the shaft meets the actual switch - if you get epoxy on there your switch won’t actuate anymore.
After about 4 minutes of setting up, your new Express van knob will be completed and done.
While you’re cleaning up the OBS interior, don’t forget the small stuff. Our OBS or DIE air freshener is an easy cab upgrade for your GMT400, Silverado, Sierra, Tahoe, Suburban, or Yukon, and it finishes off the fresh interior look.
Related OBS / GMT400 Interior Upgrades
If you’re cleaning up the inside of an OBS truck, these are worth doing at the same time:
- OBS HVAC Knob Swap Using Chevy Express and GMC Savana Knobs
- OBS Escalade / Denali Console Swap Guide (GMT400 1988–1998)
- 96–98 OBS Interior LED Upgrade
Done the headlight knob swap on your OBS? Post your pictures, your measurements, and how you tackled the shaft - always good to compare notes.