Hey people,

I've got a 2003 base mini.

I know this problem is all over the forums but I wanted to explain exactly what I'm experiencing to see if anyone can help me properly diagnose the issue.

So I'm getting a violent wobble while accelerating usually while over 40mph. When I let off the gas it stops. Vibration is mostly felt in the seat and shifter, but not really the steering wheel so much, although it can be felt there too.

My first thought was CV Axles need replacing, so I had both replaced, but wobble/shake remained.

I inspected the mounts and there is a small tear in the lower mount that sits next to the power steering fan. It appears to be a very small tear. I'm going to replace this, but could it really cause a wobble like that?

By the way, I only see a mount labeled as the (rear), is this the correct part? It looks right but would like verification if possible.

After replacing this I am thinking to get my wheelsbalanced and possibly aligned, but I'm not confident that would solve my issue.

Any advice would be greatly appreciated.

 

Perhaps a bearing but would think you could hear something as well. How old are the tires, I have had belts in the tires rip and wheel will wobble.

 

thanks for the reply.

the tires look good, and I checked the bearings. One was shot I replaced that and the grinding sound went away, but not the wobble.

 

Any recent potholls?

 

No potholes recently, no.

I'm curious if anyone else has had similar symptoms and fixed by replacing the lower rear mount...

 

How are your strut mounts and lower control arm bushings? The stock LCA bushings are known to go bad at fairly low mileage. Most people replace them with powerflex street urethane bushings.

 

Thanks RB-MINI. I'll probably replace the LCA bushings based on your recommendation. They look like they've gotten use but are not obviously shot. Anyway, couldn't hurt to replace if it's a common issue.

 

Passenger side def looks shot

 

Is it worth changing the arm itself ? What about the third location going towards the back of the car? Is that something I should replace?

 

If the third location at the back of the arm is what you're referring to (Pic 6 in the Pelican article below), that's the LCA bushing that does not last and is usually replaced with the powerflex bushings. Your pic looks like the inner and outer ball joints. You shouldn't need to replace the arms if they aren't bent or damaged, just replace the ball joints and LCA bushings.

Here's a great tech article from Pelican Parts. You can order the parts from them also, if you don't already have a source for them. They show another brand of urethane bushing in the article, but the Powerflex are a similar three piece design and are also available from Pelican. As far as hardness, I'm not sure which is harder or if they are comparable. If you search the forums it seems like almost everyone uses or recommends the purple Powerflex street bushings.

http://www.pelicanparts.com/techarti...eplacement.htm

 

The weird thing is that it's only under accel and not coasting. That makes me think not typical tires, improperly mounted wheels without hubcentric rings, or LCA. I'd say it needs to stem from the power source. If it were a BMW I'd have said look at the driveshaft, so I guess I'd start with CV joints as the FWD equivalent.

LCA is a bit of a project since you need to drop the subframe or cut them out with a sawzall. I'd start with simpler solutions first and make a plan for the LCA project.

 

Sorry, had the tab open for a while so there were some other responses. I wouldn't do the arms. Poly bushings should go in easy so just remove the old rubber ones. I just had mine replaced with powerflex and honestly don't notice too much difference from stock, other than they'll last forever.

 

My first thought was CV axles and I had them replaced. I don't have hubcentric rings. Is that really going to make a difference?

 

They absolutely do for aftermarket wheels that don't have the same hub bore. If you have oem wheels then they're unnecessary.

 

Wheels are Stock, thanks for the info though.

 

Hub centric rings definitely make a difference if your wheels do not sit on the hub properly, but since you have stock wheels - this shouldn't be your issue. If you've tackled wheel bearings and other items, bushings are definitely a good place to start. The LCA bushings, when bad, have been known to cause problems on these MINI's. Really inspect your ball joints too as while you're in there it may not be a bad idea to replace them as well. Our article that RB posted above should help a bunch. Let me know if you need anything.

http://www.pelicanparts.com/catalog/...pg4.htm#item25

 

I just ordered both side inner and outer ball joints and bushings ( the purple ones ), tie rod ends, a transmission mount and transmission mount bushings, from Pelican Parts. I'm going to install all this hopefully by Sunday if the parts come in, then get an alignment.

Thanks everyone for the assistance. I'll post back with any news. Hopefully good news.

 

I made all the upgrades except for the trans mount. Got it aligned and balanced the tires. Still drives the same, still shakes.

I'm praying that the trans mount is shot to **** because if not then I think I may be looking at a bad trans.

 

Have you done anything to the rears at all? Not sure how I missed it the first time around, but you said you feel it mainly in your seat - means it's likely not the front wheels. Transmission could be it, or in the rear.

 

transmission mount didn't help. I've done nothing with the rear but I feel it more in my feet than the seat. I still think it's coming from up front, especially since it's a specific window that causes it (40-70mph), and during acceleration. After that the shimmy goes away again.

 

I am sorry for your pain. Elusive vehicle shakes at certain speed is one of the most difficult cause to track down. I have done some over the years. Of all that has been discussed, I will least suspect the cause can be from the transmission - assuming you have manual gearbox. Everything in there has very little angular momentum. I would suggest the following:

• Clutch and flywheel: There was a member here with a shattered pressure plate (which has considerable angular momentum - like the flywheel) and surprisingly he could still drive the car. It is very uncommon.
• Engine crank damper: Do not underestimate insidious effect a failing harmonic balancer can have on the smoothness of the car - like a unbalance load of wet clothes in the washer during spin cycle.
• Tires: This is one of the hardest to identify. I have spent ample time looking for at speed and speed range specific vibration and eventually I narrowed down to a tire with internal belt structure deterioration. And yes, this is after taken the vehicle to a racing tire/wheel specialist to have all tires balanced and checked out OK, as well as after closely examined the roundness of all the tires.

A tire can look to be perfect on the outside and still have internal belt separation and what matter most is the degree of deterioration. Gross failure is easy to spot and identify. Lessor failure can evade detection on the modern balancing machine as many don't spin terribly fast nor the tire is under load.

In the above discussion, I would take exception to those that insist hub ring is always necessary for after market wheels. I have never own any hub rings as I don't want to deal with them if I can avoid. And yes, there are even plastic hub rings. Hub ring is not necessary with aftermarket wheels that is lug-centric with correct lug patterns and geometry. Hub ring is often necessary for cheap aftermarket wheels that do not have proper lug pattern and/or bad lug dimensions and proper tapers. lug centric wheels rely on the lugs to center the wheel to the hub, notwithstanding the hub hole dimension of the wheel. A correct hub hole dimension in these wheel only facilitate wheel change.

 

thanks for the response pnw... and thanks
For the sympathy. That suspension work wasn't exactly easy, and tô see no change after all that and paying for alignment and balance, it starts to get pretty frustrating.

I'm gathering from your response, that maybe rotating the tires and seeing if the location of the vibration changes, might be a good check.

I haven't checked the balancer but I'm thinking this would cause the issue at all speeds and not specific ones, but maybe I'm wrong. I'll look at it tô see if it seems off.

For the pressure plate not sure about the symptoms either. There is a slight slippage right before the clutch is completely released when upshifting, and a slight vibration felt when resting my foot on the clutch.

 

Swapping the front tires with the back will help you narrow down if a tire/wheel is causing it. I am surprised that you haven't try this already. I also recommend putting the car up on jack stands, and carefully check for tire runout (variations on the outer circumference of the thread surface). Even the best tires will have runout and it take some experience to know what is acceptable runout. Check you wheel for bend by rotating it and use a makeshift dial gauge if you don't have one. Pieces of 2x4 wastes stacking up will make a poor man's dial gauge.

Look for abnormal shape of the thread surface carefully due to internal belt separation. A scrap piece of 2x4 can be use as a reference as you slowly spin the tire.

How old and how many miles do the tires have? Also have they been abused due to over or under inflation?

 

A couple more things that come to mind:

The base has a spare tire, and you can use it to swap out each of the 4 wheels one at a time if it is in good shape like most spare wheel is never/seldom used.
A tire with deteriorated internal structure will act like tire balance weight that will move around with rotational speed.

You might also try to slightly over-inflate the tires to help observe the possible tire belt separation. I use the term belt separation very loosely here, as in a modern radial tire there are much more than the good old steel belt inside. So I mean all the reinforcements that holds the rubber in a proper shape of a tire.

Speaking of speed, I just have to rant every time when people use the phase "high rate of speed". "Speed" is a rate and there is no need to qualify it with the word "rate".

 

I don't know why I haven't tried a rotation .. maybe I was set on it being drivetrain or suspension related. I'm going to try some of your ideas and I wouldn't have thought about utilizing the spare tire but that's pretty clever.

But really, could these tire issues only show symptoms during acceleration ?