If they won't there's always a way for a quick test drive (like a makeshift spring rubber).

 

It really depends on the coilovers. Some, like the megans, would go an inch HIGHER than stock. Things like the body length, and lower strut housing design play a large part in whether they could get back up to stock height.

 

I did not look anything that is not heavy duty trackable so those coils were not on list that I evaluated.

What about the people with KWs and Eibachs coils? They cannot adjust back to stock height. So not everyone with coils has that option to easily do this test without introducing something like a rubber spring helpers.

 

As the coilovers are made with the center of their stroke for a lower static height. The information we really need to know is what is the overall system travel, so we can see if there is sufficient travel when adjusted where we want it. I ran stock on V1's in my RSX before I lowered it.

This is just one more "missing" spec. Things like "19mm bar". Meaningless. What is the stock bar stiffnress, and what is the aftermarket stiffness. The lengths and material matter. I guess they assume wa are all to ill-informed to understand actual specifications.

 

You are correct, some of the coilovers such as the KW's can not reach stock height. I was just pointing out that SOME are capable of it, so you could test it out if we think that would help solve this problem.

For some of the suspension systems such as BC, Ksport, Megan, etc the travel does not change through the height adjustment as the height adjustment is independent of the stroke. They have threaded strut housings which the body threads into. That can be a very nice option.

Overall travel for the car in stock form is about 1.9" and that's with full compression of the bumpstop. About 1.4" is when it comes into contact with the bumpstop if I remember correctly.

The travel specs are out there if you are interested. Travel was my big interest when developing my suspension so I paid attention to the options and the travel they offered. Ended up settling on custom struts because I couldn't find anything that suited my needs. Sometimes it just requires a quick phone call or email to the company. I found all of the main coilover companies helpful when it came to sharing the travel specs.

Things like the swaybar stiffness are readily available on any of the companies' sites. People just shorten it to '19mm swaybar' for ease of listing their mods.

Examples:

Under "features" here: http://www.altaperformance.com/produ...-Bar-Rear-19MM

At the bottom of the paragraph here: http://www.hotchkis.net/mini_cooper_..._rear_bar.html

 

Alta lists them. Koodos to them. Not common. Hotchkis lists % increase for their race, but not their sport bar. I admit I never looked in detail at the Alta as they use welded ends. I am not suggesting they have any issue with that, but I had a very bad experience many years ago with a welded end failing on another brand. For my piece of mind, I bought the H&R.

 

When dropping the Mini, the axle geometry changes. My mechanic is stating that the axle now becomes too long, causing this issue. It's common on a lot of FWD cars that get lowered apparently. Some get it, some don't.

That RPM range also seems to aggravate the issue for some reason.

Would be nice if someone smarter then I could really put this one to bed with some good details and if we are actually doing any damage to the car by living with it.

 

Not sure I buy that without a bit more information. Does anyone have good detailed exploded views of all the parts involved? Where is the slip joint? Why does it not get worse with the more cars are dropped? Is there a "bad spot" where it is a problem, and not on ether side of that? Never heard of this in any other car.

This issue keeps getting deeper in hearsay, and no stats are being gathered, no proper engineering investigation is being done. Vendors are not being pushed, and I guess the desire to look cool is greater than it working properly.

 

..... and you're an expert in this area ?!?!?! What kind of statement is that? For example, it's a WELL discussed issue in VW circles just as one example. So why make statements like this when you really don't know any better......


This is the most ignorant statement in this thread yet. How can you have any F-ing clue as to what others are doing on this issue or why they have choose the path they have. I'd bet you have NO CLUE. Your post is not in the spirit of what this forum is about.

 

realoem.com has them

Because the axle angle and drop PROBABLY aren't the issue, IMO. I'm still hedging on install error.

Since you're the one complaining about people not trying harder to understand this, how about you take a second to park your car (not dropped) next to a car on lowering springs (not coilovers). Peek your head under there and tell me what angle difference you see in the axles. I think it will really put things into perspective for you.

I've been under MINI's of all sorts of drops from .5" to 6", and I can tell you that dropping a car 1" hardly changes the axle angle and it certainly doesn't put it at an angle that would be enough to cause binding. I've taken my CV joints apart and examined them. The angle at which things start binding would be pretty large.

You gotta get out more, I've heard about it from nearly every FWD car community I participate in from VW's to Honda's and everything in between. It's a pretty common and well known problem (assuming it's axle binding).

It's because most people aren't concerned about a tiny, hardly noticable vibration that seemingly causes zero damage to the car. The same way people tune out the slight rattle that MINI's have from the factory. If you were to worry about every tiny inconsistency in a car, you'd go crazy and modifying cars probably isn't the thing for you.

 

I wouldn't call anyone that makes a statement like that a mechanic.

In a properly engineered drive system there is always some mechanism to compensate for the necessary length change as the suspension moves throughout its entire 'designed' range of movement. Our cars have a slip joint or as noted in the picture, "double offset joint" at the inboard end of the axle shaft. Since BMW engineers are not known to be idiots I'm sure our shafts are designed to accommodate the full 'designed' range of movement. So unless your "mechanic" has done something to your car to increase the 'designed' range of movement it is entirely unlikely that the axle now becomes "too long".



There is a remote possibility that when our cars are lowered it puts the shaft into an area of the travel that is not optimal but I would not expect that to occur at a minimal angle change.

Since cv and u joints are designed to work properly with some installed angle one possibility might be that when we drop our cars a certain amount we are perfectly aligning the axle shaft causing a harmonic. This is plausible but unlikely because the shaft would have to be aligned almost perfectly in all axes.

Spinning an object at different speeds will introduce different levels of harmonics. That's why RPM could aggravate the condition. If it were related to the axle shaft I would think it would have more to do with wheel speed than RPM.

This is the most ignorant statement in this thread yet.

You asked for it and when you get it you lash out at someone that's trying to help.

tvrgeek merely stated that he "Never heard of this in any other car". He did not say 'this is not an issue with any other car in the world'. He is just trying to help figure out what is causing the issue. The more actual data we have the better. This could help us find a common thread that's not obvious on the surface. tvrgeek seems to have a reasonable amount of intelligence based on several of his post that I have read. Please keep you negative comments to yourself.

But don't mind me I don't know what I'm talking about and I don't know anything. I just make up things as I go along. I wish someone smarter then I can figure this out so if it happens to my car they can tell me how to fix it.

I'll go back under my rock now...

 

Is that the actual MINI axle? If so, cool. I was told we had a three ball "Y" CV joint, where this picture is a more traditional multi-ball; much closer to constant velocity than the 3 ball one and much less sensitive to phasing.

This is the second time it was pointed out the vibration seems to be engine RPM sensitive, not road speed. Very interesting observation.

Rally, Maybe I live a charmed life, except the list of issues with my Mini would suggest not Yes, I do go crazy with every inconsistency. That may explain a few things. It is what makes this a fun hobby. I am just very curious and think of myself of at least a decent hack level engineer. ( No state board so it is illegal to call myself an Engineer).

What is frustrating me most is one of my past careers was in failure analysis. Here is an interesting problem and I have no facilities to investigate it properly.
I have suggested some stat collection, but that seems to have gone unheeded. As an experiment, I think it would be revealing if a damped mass could be added to the axles on a failing car and see what it does to the frequency or susceptibility of the problem. I would want to record it on a spectrum analyzer before and after. It could be revealing to artificially excite the axles and see what their natural resonance is.

Is everyone SURE it is engine RPM, in all gears? Not that it is noticeable when you settle down and cruse in top gear? Does it take a while to start where it may not be noticed moving through the gears?

 

No, that appears to be a subaru axle.

It seems like most of the people report it mainly report it from 2k-3k and usually only in 1st or 2nd gear.

 

His opinion. I'm no mechanic and all I was doing was putting out there what I was told.

I don't necessarily agree with this. I don't believe that our drive axles can actively move in and out quick enough during suspension travel. What I do agree with is that the suspension should be able to compensate but not by physically moving in and out.

Agreed.

I think it's the loading on the axle at that RPM during acceleration that's causing the problem or something related to that. It's got nothing to do with wheel speed as during coasting, this issue does not arise.

I may have over-reacted, however................ I don't take kindly to people taking a crap on an issue and then making a general insult insinuating that the group doesn't care about anything but wanting to be cool and compromising their cars to do so. That's just BS. AND worse yet is your ignorance in supporting that comment. You guys best mates or something ??


Buddy, where's he trying to help out in that post !??!?!? Hello !?!?!?? What are you reading ??? You seem blind to the fact that he started with the negative comments and THAT was what I was commenting on.


Dortoh, it's great you posted that fantastic picture BTW, and commented on the obvious design elements. Thanks. AND, for the record, BMW engineers HAVE been known to be IDIOTS. I've seen it first hand............ say with the E46, E53, E39 3.0 litre inline six that hydrolocks because of a very VERY stupid design fault. And the list goes on. So don't feed people that crap that BMW design engineers are not idiots. They have their moments .............. they are only human. And this Mini issue may just be another one. Who knows.

 

tom,

Slightly tangent. Don't confuse engineering organizations who can act very stupid as a whole with the individual engineers being stupid. A good case study read is the old book "On A Clear Day You Can Almost See GM". Only the first half, the second half was just John Z defending himself.

 

I'd agree with this... I notice it more when the car is under load, as in right at the beginning of 2nd and 3rd. There still is a noticeable vibration at WOT in 5th or 6th as well. On my car, im 99% sure its the drivers side DS.

 

tominizer,
Maybe you have had luck disagreeing with facts, I have not. My statement is purely fact not speculation.

I'm sorry you find tvrgeek's post insulting or inflammatory. I have reviewed it several times and I do not, but I do yours. My comment on him trying to help is based on the overview of several post, not just one. BTW...I do not know him any more than you.

As for the RPM issue there may be some additional testing that can be done. Since I don't have the issue yet I can't try this but maybe you can. Try driving your car through the problem zone under various throttle positions, (hard, medium and light acceleration) and see if there is any difference. But I tend to agree with Rally I'm not convinced the problem is with the half-shaft's. BTW...I do not know him any more than you.

I'm glad you appreciated the picture and the comments they were mainly for you since you have been misguided by your mechanic.

As for the engineers at BMW I have been a first hand victim of their human moments but I would hardly consider them idiots. When a company or an individual tries to be on the leading edge it sometimes bites you in the glutes. I would hardly compare the complexities of an ICE (internal combustion engine) to that of a drive-shaft. If BMW or KIA for that matter can't get a drive-shaft correct they have no business being an auto manufacturer.

If you have an issue with me or anyone else for that matter let's take it elsewhere. This thread is not the place for it. I will only respond further in this thread if it adds benefit to the issue. Please use PM if anyone would like to address me regarding anything besides the issue at hand.

 

Wow, how can a great thread have such nasty slams

Here's a thought - let's assume engineers at BMW do know what they are doing, same for VW, etc. So lets just figure that these axles are capable of running perfectly well, when new, at the very slight angle change that they are experience when the car is lowered given that they have to run at the full (or most) of the full suspension travel and this is probably no different from having 1 person in the car vs having 4. Also, the thread says this occurs with cars other than Minis. This would seem to say the problem is not the design of the Mini axle but something common to the axles of multiple designs. So you would be looking for something that was occuring in the same or similar way in multiple disigns that otherwise have no connection...One thing that is common to all cars is wear. The other is grease deposits. With a CV joint or any ball bearing the wear will be in the location that the ***** run most of the time. A slight angle change of the axle will put the ***** of the CV on the edge of their wear area or where deposits are. The more load (torque) on the axle (1st/2nd gear) the worse the problem will seem. A heavily used car will have more wear than a daily commuter thus having the problem at lower milage.

How's that sound Just something to think about

 

Eddie,
That's an interesting theory. I currently have less than 2000 miles on my car. I hope to install the coliovers soon (maybe tomorrow). I will report the results ASAP.

 

whatever......Dortoh. Don't make it sound bigger then it is.

Anyways, my mini has 30k km on it. The issue is mild. If it's a wear issue would it not get worse or better over time. A few owners have reported no changes. VW owners lived with it with no changes to the condition.

I tend to agree it's not strictly a BMW issue. And someone can correct me if I'm wrong, but it's limited to FWD cars only?!?!!

If I had to give my best guess, I'm thinking that under a certain RPM and loading (acceleration) somehow the bearings are getting pushed harder onto the loading surface and slightly binding?!?!! Can someone also comment of this...... as the driveshafts heat up under use do they expand....... complicated by the new suspension it's neutral position?!?!

The slip joint..... more info on how it actually functions under loading would be interesting. If the drive shaft is heating up and expanding, is it possible it doesn't help in any way to accomodate suspension geometry changes during operation of the vehicle.

One last thing. Installation error has been mentioned. Thoughts on what exactly is being done wrong. No one has discussed what possible mistakes during thd install process. Slip joint changes, etc?!?!

 

Is it possible that when lowered the "typical" amount, of about an inch and a half, the axle is actually VERY straight? This would be bad as it would unload the bearings more. It is well known to cause vibration issues in drive shafts. I feel stupid for not remembering this earlier. Any double joint shaft actually needs some miss-alignment

In a similar line, why I asked for stats on camber, if it is possible that either end of the shaft is perfectly aligned. A quick test would be to change the ride height both directions away from level and see if it persists.

Does anyone know some whoopty-whoop roads that would slowly run the suspension through a large range right at the resonance speed? Another interestingly test maybe.

 

Interesting ......

Can someone else try this as well. Does your mini do this rite off the bat when you head out and the drive shaft is cold or do you only really notice the issue after the bearings have warmed up through use.

 

Worth a try, but I don't buy the scenario. I am very familiar with binding spline joints. They hang and pop. If it is a Y type CV, then the end play is in the long slots the outer bearings ride in. I seriously doubt binding.

I CAN buy some amount of tolerance which gives the space necessary if the shaft is too straight to vibrate and is damped better when the grease is cold. However, modern grease is very consistent. It is not like the good old axle grease you had to heat to get out of the can.

 

After I posted, I got to thinking along the same lines. The axle is staighter. I will admit that my wear theory doesn't hold up too well if the axle straightens and there is less movement of the ***** in the CV. But it was a "thought" for a moment

However, with the staighter axle, there may also be a compounding issue with the manufacturing tolerances and/or slight out of balance. A little looser, more vibration I'll throw the "wear" thought out on that one too (OK I won't push too much on that one), but it does go along with tolerances. And something needs to explain why on some cars and not others.

Your test sounds to be worth a try. Might it work by just jacking the car up and letting the front wheels just hang? You could put the car on blocks and use the jacks to raise the wheels to the factory height. I know, it shows up with load, but if it is a vibration issue it should still show up because it is still a spinning mass. Without all the other road "noise", you may be able to detect it. Taking the front wheels off would remove that as a source of vibration as well. Thoughts? Just make sure, if you do this, that the car is secured and safely supported.

 

Been away on vacation for a bit over a week and BAM! all sorts of help and defamation! Either way; I'm still experiencing the issue as stated before and based upon responses & "things to try", some can and can't be achieved. Someone asked if I could raise to stock height and that answer is "no" without putting my old suspension back in. My Mini has 22K miles on it, but I don't think age/mileage makes much a difference. Running temps don't make a diff; I can reproduce issue right out the gate. What I do notice is that if I'm going uphill I can "feel" the issue much more than down, which plays into an angle theory. I can easily reproduce the issue under any load, any gear, at almost any speed provided I get the RPM range between 2-4K. Speeds do not affect the shake; been over 100 without the issue!

Sadly my car was in an accident before I bought it (unbeknownst to me) so that could be contributing to my issue. I was also "lucky" enough to have Discount tires bust the seal on my front right tire so they replaced it with a new one vs. a "more worn" tire on the front left, so that could be a contributing factor (though it had no affect before I lowered it). I'll rotate/balance this weekend if I can get out of my parenting duties.

My shake seems a bit more violent than others so I need to get this fixed asap. I'm going to take my Mini in next week for a clutch issue, so I'll ask if they'll look at it with aftermarket suspension. Can't hurt to at least talk to them about it to see if they've heard of this issue before.