Looking for input from folks with MCSs with factory LSDs, especially those who also have personal experience with MCSs without LSD, and can contrast the two.

Here's my situation. I have an 04 MCS (w/o LSD) and an 05 MCS (w/ LSD). The wife's 04 car drives and accellerates quite smoothly all the way to redline. The 05 car is quite rough in comparison. From the time it was new it has had a vibration (or shimmy) at rpms above 4000 when driven hard, particularly when accellerating hard out of a corner.

In addition, the 05 car is uncomfortable to drive for long distances because it vibrates pretty much all the time cruising down the freeway. The 04 MCS is much more comfortable to travel in, even though it has run-flats (05 car has Pirelli p-zeroes)

The dealer has driven the car several times and felt the symptoms, and seemed to think it had something to do with the drive-train. They replaced the flywheel, which initially I thought made it better (maybe tried to convince myself)... but the shaking is still there. The dealer has the car again, and had a different person drive the car. The dealer is now saying that cars with LSDs just have more vibration than those without. This feels like a story to me, but I have no way of knowing if this could truly be part of the LSD experience. Anyone have enough comparative experience to offer some thoughts?

I'm continuing to think there is actually something wrong that needs fixing.

The two cars are equipped thussly:

04 MCS, Alta 15% pulley, Alta intake, H-sport comp sway bar - otherwise stock including tires and wheels.

05 MCS, factory LSD, Dinan stage 5 software, Dinan intake, Dinan 15% pulley kit, Dinan throttlebody, Dinan exhaust, Dinan 19mm sway, JCW suspension, 5zigen wheels, p-zeroes

BTW the 05 car has exhibited the same behavior since new, when it had only the LSD, and the aftermarket wheels and tires. Note also that I spent a lot of time and money changing tires, having them road-force balanced, even switched back to S-lites w/ runflats for a bit. None of that changed the vibration/shimmy/shake behavior.

Thanks in advance for any help you can offer. Brian

"If it's not right, what is it? IT'S F***ING WRONG!"

 

I have the factory LSD in my 05 MCS, but I've never owned an older MCS so I don't have a comparison to base it on. Sometimes it shimmies... but mostly when I'm giving it too much power (which, I'll admit, is quite often!). When I drive smooth, it rides smooth. I think that if anything, the shimmying is the LSD doing its job, transferring power between the wheels. Without LSD, you probably get more wheelspin instead... smoother feel, also slower go.

I tell you though - on the Dragon, pulling hard out of curves... I could DEFINITELY feel the LSD pulling me through. It was awesome. I'm glad I have it.

 

2005 w/lsd here. Granted I've never been in a MINI without lsd for an extended period of time, so I can't really compare, but my car has never vibrated or shimmied (sp?) as you describe. Even with the cr*ppy runflats my ride is pretty smooth on highways.

 

The LSD shouldn't be doing anything when you are cruising down the highway in a straight line, both front tires will be rotating at the same speed, so if you are getting vibrations there I'd say your problem stems from somewhere other than the LSD itself. I've driven a non-LSD MCS back to back with my 06 MCS w/LSD- as long as you aren't fighting for traction or making a tight turn (parking...) you shouldn't feel any difference in the two.

Jason

 

Agree w/Jason--when driving straight, the lsd should be "seamless"--i.e., should not be felt. Only when exiting a corner, under power--then you will feel it engage.

I think your problem is in the wheels/tires--and even though you have balanced them and changed sets--I would try another set of wheels, just to see.

 

It's not your LSD. Consider getting an engine strut brace. Do you have 17-18" rims with run-flats? That'll give you a rougher ride. Maybe something in the Dinan package? Mine in a factory JCW, and is smooth as silk on a smooth road.

 

I have to agree... 06 w/ lsd and no shimmies before and after the Dinan brace, currently at 10k miles and on stock run-flats...

 

Same here - 06 w/ LSD & I only notice it (slight shimmying) when I'm pushing really hard through a corner (esp really tight ones). I've only test driven earlier MCSs w/o LSD & mine feels just as smooth normally.

 

Check your engine mounts, been reading about leakage/breakage on the recent models... and never accept "they all do that" unless you personally are allowed to drive a statistically significant sampling.

 

I Have an '02 MCS with an OEM '05 tranny/LSD. After the swap it is every bit as smooth as the original (just a bunch faster acceleration from the lower gearing and better traction). They are feeding you a line of... ! Something in the driveline, wheels or tires is out of balance. As DixonL2 suggests, it could be motor mounts too.

 

Thanks all!

Yeah, I'm skeptical of the LSD explanation too. On my way home today with the car, I ran the revs up to about 4000 on a straight road, cruised a moment at that rpm and then tromped it. The car shimmied. As some of you have pointed out, this straightline behavior doesn't make sense for the LSD explanation.

FWIW tires and wheels were my thoughts for a long time. As I mentioned above, I have changed tires, I have gone out of my way to pinpoint balance them, I have changed to stock s-lites with run-flats that rolled perfectly on our other car. When I am driving on smooth pavement, if I rest my fingertips gently on the steering wheel there is NO vibration in the steering wheel... but I still get the shimmy on acceleration no matter what. I am convinced that this is something other than wheels and tires.

Don't think it's any of the Dinan stuff since it has done the shimmy since BEFORE any of the Dinan was installed.

Could be motor mounts. How does one go about checking these? Check for leaking? Check tightness?

Anyhow, thanks again for all your thoughts!

 

Now that you give a full description, it sounds like it could be a problem in the CV joints. If you have another dealer in your area, you might ask them instead. There is great variability in service department quality at different dealers.

 

Have the LSD no vibrations (clicking flywheel though). Drove an 05 MCSa for a week to compare it to a non-LSD car, and ridden in many many non LSD MINIs for brief periods of time. I can tell whel the LSD kicks in from steeringwheel feedback and my ears (slight tire slip then grip returns to the wheels and the steering wheel vibrates a little. Never had a vibration, if you;re getting a vibration and the dealer is blaming the LSD then they need to replace the LSD internals.

Could it have anything to do with the JCW suspensin though? Stiffer and under load (unknown about proper install) causing things not to transfer porperly thus creating unwanted vibration?

 

I own a 2003 MCS without LSD, but had a friend's 2006 MCS with LSD for 4 months (until last weekend). I never once felt a shimmy in the 2006, and I drove it from Los Angeles to the Dragon in NC/TN. I did several Dragon runs and it performed beautifully...very smooth. I'm sorry you are having problems.

 

05 MCSa and 06 MCS (with LSD)

both cars drive similar - no shimmy. The only time I ever feel anything odd is when I really get on my 06 getting in or out of a corner, but I think this is more of a factor of beating on a FWD car than anything at all with the LSD.

 

could it be that teh JCW suspension on the '05 car just doesn't damp the high frequency vibrations as well? Unless the road is glassy smooth, you may be feeling the road and be mistaking it for an imbalance/shimmy. As others said, my first instinct is to say that its the wheels/tires. I'm assuming you have hub rings for your aftermarket wheels of course. If its not that, then its probably just the suspension giving you more "information" than before. . .

 

GP with LSD and JCW suspension. Smooth as glass. As smooth as our 05 MCS.

 

The JCW suspension shouldn't have that effect. Mine doesn't. The harsh ride in mine is more because of 17" rims and run-flats.

I would still look at wheel balance, alignment, mushrooming, and maybe anyting foreign in the tires.

 

I had '05 MCSa w/o LSD. Now I have '06 MCS JCW with LSD. Never noticed what you described.

 

Went and intentionally played around this afternoon looking for an LSD vibration, notta.

 

No issues on my '05 MCS w/ LSD either. I do have a bit of vibration on HARD acceleration but that didn't show up until I put on lowering springs which is a well-documented issue that doesn't seem to apply to your situation.

 

Thanks everyone for your thoughts! Sounds like a virtual consensus that a healthy LSD should not vibrate - and certainly not in a straight line. If it is the LSD, there is something wrong with it and it needs to be fixed.

I made an appointment next week to have MINI Madness in Portland (nearby) drive and look at the car to give me a second opinion. After hearing what they have to say, I should be better educated when I take the car back to the dealer for a fix (assuming of course that the problem doesn't turn out to be something I goofed up, which I think is unlikely).