I still have a horrendous vibration under power, slight at 18mph, really bad between 30 and 35mph and worse the more throttle you give it.
I thought it might be the transfer box not liking the worn front tyres. Had some fresh ones put on on Saturday. Zero difference, didn’t alter the speed it happens in the slightest.
Today I removed the front propshaft, making it rwd only. The facelift x5 like mine always drives the rear wheels, with a chain and electronically controlled clutch sending power to the front when needed. With the prop removed there’s basically zero load or drag on the clutches.
Still vibrating just as badly.
I’ve been under it a few times and just can’t feel any unwanted movement or feel any play anywhere. Changed the rear differential oil the other week and all looked fine, no burnt smell, no chunks, no metal paste.
Unfortunately it’s at the age where nearly everything is old or worn but probably hasn’t been replaced yet.
It was still there to a degree with the winter wheels, but definitely worse with the fat 20s. Makes me wonder if it could even be a rear damper struggling at a certain resonant frequency. It’s so big and heavy a standard push down bounce test doesn’t do anything at all!
I’m trying not to scattergun parts at it and only replace parts I know are more worn than it like, and I don’t have an infinite pot of money (or time!)