04 Suburban high speed vibrations
Happy New Year!
My 04 Suburban has a vibration that has torn out 2 rear ends so far. Just turned 200,000 miles. Even though I've wasted thousands so far, I love the vehicle itself & want to FIX it somehow. I'm more than willing to pay a local welding shop to add extra supports if needed, or buy different diameter tires/rims, or whatever it might take: I'd just like to know WHAT it needs.
With over 10 years of GM'* vibration problems, I'm hoping SOMEBODY understands what is occurring & what might be done to fix it.
Any help would be GREATLY appreciated.
Initial vibration was only noticeable at 73 MPH (started at 71; gone by 75) Whether in gear driving or coasting downhill in neutral with tach at idle. Same in 2 or 4 wheel drive
Since rear end replacement now at slower speeds 30'* & 40'* also
Cruising at 67 is still smooth as a rail (at least for now)
500lbs at back of cargo area slightly helped the 73MPH, but worsened the lower speeds.
Just my own wonderings:
1. Rims & Tires weigh more than they used to; creating different weight distributions compared to the rear end. I'm told Ford adds "tuning" weights to their rear end housings, but haven't heard exactly why or how to.
2 Maybe use 15" rims like these vehicles had in the old days before vibrations issues began......
3. This has a transmission mount under the transmission, but the transfer case just hangs in midair. Seems like a whole lot of weight not be be supported anywhere aside from being bolted to the transmission.
4. Possibly add a support &/or carrier bearing to the back of the transfer case?
Even mix of local & interstate driving.
04 Suburban LT 5.3 3.43 rear end 265/70R17 Tires
No accidents/damage of any kind
New Rear Shocks
Balanced Driveshaft locally
New U-Joints on Rear driveshaft shaft both Front & Rear
Replaced entire rear end housing, pig, axles, bearings, rotors, brakes
Rechecked balance of driveshaft at specialty shop correcting a small bow .055" out of round