Needing to pick the brains of everyone. Been chasing a vibration on this Envoy for at least a year.
Here's everything I have done..
Replaced the tires with new Michelin
Road force balanced the tires
Complete front end suspension was replaced 2 years ago
Replaced both front wheel bearings 2 years ago.
New Bilstein struts 3 weeks? ago
Removed both front CV Axles
New front rotors and pads 2 weeks ago
New rear, rear most, u joint 1 month ago. Front was still good.
New rear rotors and pads 1 year ago
Replaced the rear wheel bearings and seals today
Verified it isn't the spare tire by removing it
Yes the dif is plugged at the CV Axles hole.
I may remove the front drive shaft tomorrow, but I seriously doubt it's going to solve the problem. Since the CV shafts are out, it shouldn't be spinning anyways. Front dif is still full of fluid verified today.
I also checked the lash pinion to main gear, and it's perfect. Surprisingly since this is the first time the dif has been opened since new. No there wasn't any forbidden sparkles in the fluid that drained out. It was clean, clear, and in great condition. I replaced the fluid 13k miles ago, about 2 years. Transfer case was also serviced at the same time.
No dents or scrapes on the rear drive shaft. I can pull it and send it out to get balanced, but the vibration isn't that type.
The vibration starts at about 40, and is very minor until you hit 60ish, then it's very noticeable and you can audibly hear it in the cab of the truck. It doesn't get worse as the speed changes, it just completely changes at 60ish. But it's not distinct, and it's sounds like it's coming from the entire truck, not able to say it's coming from any specific location of the truck.
Opinions?
Ideas?
Help!
Haven't been able to drive the truck for about 3 months now, maybe more