Strange vibration

So stupidly I did 2 things at once, or almost at once. I got new tires, 37" Falkan wild peak AT trail. The guys putting on the tires said I had a pinion seal leak in my rear dif, just a few drops but I wanted to take care of it straight away. Literally drove across town (never got over 35mph) to another shop who was doing doing my brakes and added replacing the pinion seal to their work. Couple days later they finished but mentioned a strange vibration at around 45mph. Sure enough there now seems to be a growly vibration at around 45-60 mph, then dies down above that. It's not a terrible vibration but it is there for sure. Second shop thought it was the new tires but the tire shop (who is excellent) never mentioned any vibration and I know they drove it a good deal as they did an alignment, drove, it tweaked their settings drove it again a few times etc.

SO.... I am wondering if the guys who replaced pinion seal maybe didn't get the drive shaft back on in phase or flipped on the yoke causing the vibration. I have never had this kind of vibration before so not sure if tires could cause this or what.

 

Probably time to get the rear axle in the air and traction control turned off, then run those wheels up and see what's vibrating. What you're describing is exactly what I experienced when I had a bad wheel bearing, but having this mysteriously appear after getting some work done is definitely suspicious.

 

Try unboting the wheels and reseating them and manually torquing them to spec. Just to eliminate the chance of a wonky seat on the hub centric.

 

^^^X2