[Gunner_27]

Hello Gents,

I have spent an arm and leg trying to diagnose a cyclical harmonic vibration.
136K miles

I have so far replaced

1- Transfer case
2- Drive shaft (front and rear)
3- All diff fluids.

The vibration seems to come on in overdrive, its cyclical in nature, starts at around 60MPH evens out @ 70MPH then picks back up at 80MPH and higher.

It can be felt in the seat and slightly in the steering.

The vibration seems to be more prominent when after warm-up or hard driving.

What can it be?

Is there a good BMW 4x4 mechanic in the PA/NJ area that you would recommend?

Thank you in advance.

[lug nut]

Did you ever figure out what was it? I have the same problem, have been trying to solve it for a year now

[batub]

Man, that’s frustrating. I’d check the guibo, center support bearing, and your mounts, because worn parts there can cause weird vibrations that show up around those speeds. Could also be something as simple as unbalanced or bent wheels. Hopefully someone else here can point you to a good BMW 4x4 specialist

[TriumphTim]

I would have all the wheels/tires road force balanced. An internal break of tire cord or other defect could be the issue.

I live in Eastern PA, the roads and potholes are brutal through winter.

[B58 parts]

Mine had the center shaft bearing well out of position, someone had just ran the nuts up with the gun not paid attention to that alignment.

Also the stiffening plate that has the front sway bar integrated can cause a shake, those bolts are only good four or five times. There's a thread on the x Outpost with the Belmetric bolts, I recommend that for sure. When mine first arrived I only drove it for a couple miles but it was terrible, two of those bolts were completely loose and the rest were finger tight.

It could be a bent rim, or maybe the wheel mating surface isn't flat and clean. It could even be something stupid with the brakes, the brake hoses will cause the calipers to drag, maybe very slightly.

Another thought, the f30 factory manual, for the transmission install, says to fit the transmission to the engine block, and snug the bolts but do not tighten. Then install and torque the transfer case on the rear of the transmission. Then to torque the transmission to the engine block. Interesting. I don't remember seeing that in the e53 manual, but either way, I suppose adding 60 lb on the end of it could pull things out of plane. Maybe that would cause a slight vibration, if your transmission was removed.

[Spraggy]

Hi
I had the same on 53 - it was the transfer box
Hope this helps