Review on 🔧 Russell 640520 -6 AN 1/4" NPSM Transmission Fitting - Improved SEO by Brad Schaefer

Does not fit! They are advertised as NPSM and while they technically are, there is obviously a thread gauge issue. I'm not sure if they added a coating that increases tolerance, but they don't screw securely into the TH400 case. (Here I have reviewed 3 cases, all NPSM, with the factory NPSM connectors removed). I couldn't rotate my fingers more than 3/4 turn before they closed. For those that have had them, you're in luck as it doesn't take long to open the case these fittings go in and once you've done that the job is done. I will not use them or buy any other Russell product.