Ok, good day today!! I believe I mentioned in an earlier post trying to recalibrate a Peterbilt tachometer. The tach I have is calibrated to another ring gear tooth count so it did not read properly on my engine. I spoke with the tech people at the company that manufactured it and found that while it's a non adjustable tach from the customer side of things there was a trim pot inside to adjust it during manufacture. They told me approximately where to open the case to access it so I went in. They warned me that the trim pot had been locked into place and the leads were fragile but I decided to go in anyhow. They were right on both points. I ended up damaging the trim pot. I then carefully removed the front trim ring to disassemble the gauge. Once the trim ring was off and the glass and seal removed the gauge would slide out of the housing. The damaged trim pot was a 200K so I ordered a replacement. It came in today and since it was raining I decided to see if I could repair and recalibrate this gauge. I was able to get the old trim pot removed and the Nwew one soldered in place. I went out and wired it in, started the engine and Walla! I got an indication! I throttled the engine to max rpms and adjusted the tach to 2900. I then eased of the throttle and the reading settled in to 700 rpm. Perfect. I then took the opportunity to clean the face and glass and reassembled the parts. The face ring had to be crimped into place carefully and slowly. It turned ought beautiful! I took it out and tested after final assembly. All good! I now have a Pete tach for my international engine. I know strange but I like the look of the classic Pete gauges.
Here's a photo of the back of the gauge looking through the access I made to get to the trim pot:
Here's a pic of the underside of the face ring after re-crimping:
Here's the front after final assembly:
At the rate I'm going this is going to take forever but dog gone it, I'm having a ball😁😁!!