Seems I've just developed some anomalous vibration under rapid acceleration @3k - 4k rpms.
It feels more underfoot but occasionally can barely be felt, slightly at the steering wheel.
I've read that an axle could cause this type of sensation. If so; what kind of movement would the axle have to cause this kind of vibration? I had recently pulled, checked the play, cleaned and repacked the bearings = all felt,sounds, looked great.
Is there anything I can I check/determine if it is an axle? - Without disassembly? Where might the movement come from?
Since I am now also at a higher altitude (5k+) I have also noticed that the Mini idles a little rougher than normal = vibration. So I'm hoping that these symptoms may just correlate to a bad/worn lower engine mount.
My tie rod ends, upper and lower mount are fairly new/low mileage so my next guess might be the axle(s) based on the vibration under acceleration.
I'm hoping it's just a bad lower dog-bone....I should also add that my Mini is pretty overloaded/weighted down than before. Enough that the car sat lower to merit me having to dial up the ride height on the coil-overs.
Any input welcome.

 

You can check the Carrier Bearing for the one axel, that might be going and can cause some vibration issues. it is Item #3 on the image...

 

Just do one thing at a time. I'd start by replacing the old lower engine mount.

 

Yes, the dog bone is so cheap it should just be replaced. The engine mount has a 11mm space on top when new.

My old mount was bottomed out on the rubber bump stop.

 

I managed to find a suitable parking lot where I could get the front end up in the air in order to investigate what might be causing the vibration I described.



I checked the play in the axles - in/out, back/forth = pretty tight w/little to no unusual float.
Checking the vertical movement; I could feel about (maybe) a 1/32" up and down movement at the inner CV bearings.
Other than that the wheels spin freely with no grinding or clicking from either CVs.
I also double checked the central support bearing and it's 3 bolts for tightness. All was good there. (I've had them come loose before which also caused a similar vibration issue.)

(Unfortunately), The lower mount wasn't the culprit. As it is in perfect new condition; as I kinda suspected (since replacing it less than 2k mi ago).
All the other engine mounts are also new and show no signs of deterioration, cracking, splitting or being at fault. All bolts torqued to specs.






At This point - I am out of ideas.

 

One last note/observation. I am now leaning towards 2wo possibilities = tie rod ends and wheels improperly balanced.
The wheel bearings were both replaced about 1,500 miles ago. I performed a string alignment myself with great success (1/16 toe). The car drives absolutely straight, center stitch on steering wheel perfectly centered @4k mark, tires are wearing evenly.
What I've now begun to notice is intense vibration @ 90 - 110mph - like the wheels are about to break loose off the car. My thinking is that the wheels were not weighted/balanced to perform over 70-80mph when the new tires were mounted 16k mi ago.
The tie rod ends maybe suspect of pre-mature wear (@12k mi(?) which maybe contributing to the vibration @ 3k - 4k rpms. and perhaps the shaking at high speed.

 

Were the wheels & tires balanced on a HUNTER Road Force machine? If not, suggest you find one and see if that helps.

 

Any chance you hit a pothole at speed or curbed a wheel recently? It doesn't take much to send a wheel out-of-round.

 

The roadways have been atrocious during my 3,000 + miles but haven't hit any major potholes. Probably doesn't matter that I'm running the heaviest and sturdious S-lites - but you are right. I can imagine that could definitely cause the sensation/vibration.
@NC TRACKRAT - Good point. No the wheels were not balanced on a Hunter during tire installation. I remember reading a post/discussion about another member having similar vibration issues at high speeds. High speed balancing had been mention as well Hunter. In hindsight - I'd wish I would have paid more attention. The roads are pretty poor and rippley up here which certainly doesn't help. Thanks for the suggestion. I'm in need of new tires soon before the winter weather really sets in. I Wil be sure to have them balanced for higher speeds!

 

It's not just for higher speeds. The Hunter Road Force Balancing equipment checks for wheel and tire run-out and faults in the tire. It simulates real world conditions.
https://www.hunter.com/wheel-balance...elite#overview

 

... or lose a weight.

 

@JABowders - For the win!!!
As much attention I pay to cleaning and rotating my wheels - It should have been obvious to consider a missing weight. Sure enough, I just discovered a bare spot on the left inside wheel where the weight had once been. Seems to make sense. I'm going in to have my wheels re-balanced.

 

Racer/track junkie trick: Buy a roll of aluminum tape that's used to wrap A/C lines and ductwork. Snip off enough to fully cover each weight with enough over all the edges to ensure that no moisture or dirt will get underneath. That will keep the possibility of losing a wheel weight to a bare minimum.

 

Pulled into a parking lot at a nearby Discount Tire, removed the wheel that was missing it's weight. Degreased and cleaned it up and rolled it into the store. I was put in queue: 'first come first served'.
The place was utter mayhem. Cars stacked up. Customers wandering off and not picking up their cars when called.
There was a line of 15+ cars waiting forever to have their complimentary tire pressure checked. 4.25 hours + $28 later they roll out my newly weighted/balanced S-lite covered in nasty greasy fingerprints.
I mounted the wheel back on and went for a quick sprint down the interstate. I still experience vibration @/between 3k-4krpms / hard acceleration. But speeds at 90 - 100mph - everything seems smooth again.
Will pull and clean the wheels and apply aluminum tape over the weights as NCTRACKRAT suggested.

 

once i had a vibration like you describe because of dirty mating surface between rim and hub. cleaned it up with a wire brush, fixed it

 

+1 on cleaning the hub as it sounded like a missing hub centric ring issue but then I saw you’re running factory S-lites. If that doesn’t solve it try rotating it to the back. If it’s a minor wheel or tire issue it might not be noticeable and help pinpoint the issue to that wheel/tire.

I had the same issue with another car running factory wheels, and after trying a Hunter road force balance two times, the solution was to have the wheel and tire balanced on the car. If you do that, you’ll need to note the position of the wheel in relation to the hub so it gets put back on the same way as now the hub and rotor is part of the balance. Also, you won’t be able to rotate that wheel because of this. My car was running a directional tire in a staggered setup so this wasn’t an issue.

 

Interesting - I wouldn't have ever thought about cleaning the hubs that may contribute to some sort of imbalance.
The car has lived all of its life in a Southern climate where there is little to no rust. I'm pretty meticulous about keeping it clean and grime free.
But I will definitely take your advice and clean the hubs when I pull the wheels again. One thing I had noticed when I discovered the weight missing from one wheel and had it replaced/re-balanced; was that some of the weights on some of the wheels were either placed on the outer most inside of the wheel (behind the spokes) or otherwise placed on the most inner side of the wheel (toward the hub). I'm really not sure that makes a difference (?)....Just an observation. After the weight had been replaced, the vibration @ 90+ mph has been resolved.
I performed a tire rotation (in an X pattern) a month or so before (less than 1kmiles ago) before noticing the vibration during my current excursion. One thing I should also mention is that I now, just re-torqued the top strut bearing nuts. Indeed the three of the nuts on the driver side had backed off to 15-20' lbs. However - I am beginning to suspect what is different (that may be the cause for vibration), with the Mini - WEIGHT. Before I've never carried more than 40-50 lbs of tools and myself (145 lbs) in the car. I have currently doubled that. The car sits much lower (esp in the rear), as a result. I'm considering that with the added amount of weight, under load, that @ 3-4k rpms the weight displacement maybe transferred to the PTO/drivetane (???). I'm no physics expert but....
Do you think that may have any influence (besides mpg and torque) ???

 

Backed off to 15-20' lbs.? Those wheel nuts should be torqued to ~90' lbs.

 

No,no - Three of the four top strut bearing nuts on the strut housing had backed off/loosen.
I re-torqued them back down to 25 lbs.

 

another thought. brakes. brakes can cause vibration. do you have any pulsing when braking? just more for the brainstorm here

 

Thanks for the continued input. No problem with the brakes. Stops smoothly and reliably. No pulsing or vibration.

 

This brings back one of the possibilities I initially dismissed since your car was lowered a long time ago and the vibration seemed to be a new issue. Several people have posted about a vibration like this after lowering their MINI’s. A theory is the cars were driven long enough before lowering that the axles had a groove wear into the bearing face and when lowered the new axle position caused it to run in and out of this groove causing a vibration.

Since you say your car is noticeably lower lately, I wonder if this could be the cause. Is it possible to do some driving without the extra cargo to see if the vibration goes away or improves?

 

I think that is a pretty good description of what may be occurring here, RB. I'm currently bouncing around from one motel to another as I work to establish residency. All the rooms available are up several floors. But I agree -loosing the load was also my intention and drive the car to feel if there is any difference.

 

It could be your control arm bushings, if those get enough mm's of play, you'll feel steering wheel vibes at rpm and at speed, but not so much during slow, parking lot driving. They tend to oval out and form stress cracks when left parked for long periods of time (ie stored under a car cover for a couple seasons). Also the passenger side typically takes more of a beating from potholes, all it takes is one side to have a failed bush and you'll be driving with a shimmy in your steering wheel. If someone else already suggested this and I missed it disregard this message, good luck

 

Thanks Whiskey -
The entire front suspension and subframe has been completely refreshed with all new balljoints, control arm powerflex bushings, coilovers,,strut mounts, wheel bearings. It remains a bit of a mystery. My best bet would be to lose the load and go from there.