More daily bomber maintenance on the rainier.
I've put 70k on it and never changed the rear diff fluid. 250k seems like a good time to change the fluid. Didn't know if a decel vibration was the gears, bearings or what so I thought I would give myself some piece of mind and change the fluid. Was expecting a oily glitter bomb honestly. I didn't know why I never changed fluid before since I know I changed the t-case fluid and trans fluid when I bought it.
Turns out I probably wanted to change it but couldn't because the fill plug was half stripped out. Took the welder out, welded a nut on and the plug came out. Changed gasket (had to buy one). I had an 8.6 gasket since all v8 and long wheel base gmt360 chassis are supposed to get the 8.6 full size pickup/suv axle. Basically like the 7.5/8.5 thing with G bodies. Turns out I had the 8.0 small differential in mine??? Either the factory installed the wrong part, or it was replaced with a salvage yard part early in its life, or people are wrong and the rear axle could be the small 8.0" in a v8.
Good news is the fluid was clean so no differential rebuilds in my future on this.
The hot wrench coming in to save the day once again