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Worn Shocks and Suspension Parts Are Dangerous BEFORE They Break!

Jul 22 16

“So, it shakes a little bit when I hit a bump. Big deal …….”

Well, in fact, this really can be a big deal.  Many vehicle owners tend to push suspension parts past the point of degraded function, simply because the car still drives and it seems to handle fine …. most of the time.  That is, until it hits a bump in the pavement or goes past a certain speed.  Then, things get a bit iffy ….. ehh, but it calms back down and on they go.

As a vehicle’s suspension ages and wears, the moving parts become loose and no longer closely control the movement of the wheels.  This can show up as vibrations at various speeds, shaking while braking, oscillations when going over bumps and even changes in the vehicle stability and direction of travel.

So, what wears in a BMW or MINI suspension system?  Typically, we’ll have bushings where control arms pivot, ball-joints where control arms connect to the wheel spindle (or, hub) assemblies, rubber mounting points for shock absorbers and the shock absorbers (or, struts, as many like to call them – at the front)  themselves.  As these parts wear, they allow the suspension components to move around more than the design parameters intend.  The parts (especially rubber mounts and bushings and the shock absorbers) may not show visual signs of failure, but they are in a degraded wear stage that does allow excessive movement of control arms and wheel hubs (and, hence, the wheels).  This can lead to dangerous shake and shudder in the suspension when traversing rough pavement or bumps.  The shake/shudder can be severe enough that the vehicle becomes unsettled and unstable, affecting braking and steering …. maybe at a time when close control is specifically needed!  For example; the vehicle braking distance will increase substantially if the wheels are bouncing or shaking on the pavement.  We have even driven vehicles that would move left or right in the lane when hitting bumps.  As you can see, worn suspension components have their own hidden dangers that may not be apparent in a visual inspection.

Take care of worn suspension parts as soon as they become apparent.

Ok, but how do I know they are worn if an inspection may not catch them?

Be aware of how your BMW or MINI drives.  You, as the main driver, are the best source of knowing when something is different.  If you notice that the front or rear wheels (suspension) are shaking or bouncing more than “normal”, especially when running over rough pavement or bumps, this is likely an indication that the suspension bushings and/or shocks are worn to a point that they should be renewed.  The suspension should feel firm and well-planted when traversing rough surfaces and bumps, anything else is an indication of worn components.

Check out the BavAuto online store at to explore the suspension bushings, mounts, control arms and shocks (struts) for your BMW or MINI … or … give our Advisors a call at 800-535-2002 for assistance in determining what you may need.

Click below for suspension rebuild kits:

Click below for Control arms:

Click below for Control arm bushings:

Click below for shock absorbers:


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Why Alternators Fail – BMW and MINI – How to Extend the Life of Your Alternator

Jul 21 16



The alternators in our vehicles are high powered electrical generating stations that are capable of supplying power levels that required a building sized “dynamo” back in the early days of electrical generation.

Today’s vehicle alternators must contend with high heat, high RPM operation and high power draw demands.  In fact, our BMWs and MINIs are quite power hungry with all of the electronics to satisfy both governmental and user demands and features.

We’ve all had an alternator fail on one of our vehicles if we keep them long enough; be it a BMW, MINI or other marque.  We’ve come to expect these eventual failures and accept them in due course.  But, can we do anything to assure the longest life possible from our alternators?

The alternator’s common failure modes  include:

* Rectifier diode failure - The alternator produces AC voltage (Alternating Current, just like you use at home … thank you, Mr. Tesla & Mr. Westinghouse), which is then converted to DC voltage (Direct Current … Thank Mr. Edison for developing DC electricity) by a circuit known as a diode bridge rectifier.  High heat can damage the diodes in the rectifier circuit resulting in a reduction or loss of the DC voltage output or damaging leakage of AC voltage into the vehicle’s systems.

* Bearing failure - The alternator core (armature) spins within the housing via two bearings (one at each end).  The bearings can wear and rattle or squeal with age, or seize, resulting in the alternator not spinning.

* Voltage regulator failure - The alternator circuitry incorporates a voltage regulator that adjusts the voltage output to match the vehicle electrical load requirements as well as the battery’s charging needs.  A failed voltage regulator can lead to insufficient electrical supply for the vehicle systems resulting in shut down of various systems or the complete vehicle.  Additionally, the battery can be under charged or over charged, permanently damaging the battery.

What can we do to help prevent premature alternator failure?

Heat is the number one killer of an alternator.  Excessive heat can damage the alternator’s diodes as well as the voltage regulator and even the bearings.  Excessive heat can be due to numerous issues, to include:

* Broken alternator air cooling ducts - Many BMWs and MINIs have air cooled alternators.  Broken or missing air cooling ducts will cause the alternator to run at higher temperatures.

Air Cooled Alternator

* Engine overheating - If not air cooled, the later model BMWs and MINIs will have liquid cooled alternators.  These systems use the engine coolant to cool the alternator.  Engine cooling system problems that result in consistent higher engine temperatures will also cause the alternator to run hotter than desired.  Additionally, the higher under-hood temperatures will overheat the alternator, be it liquid or air cooled.

Liquid Cooled Alternator

* Short driving trips - Short driving times can stress the alternator by consistently requiring high alternator output, which makes the alternator run hotter.  Ultimately, resulting in heat failure.  In short trips the alternator does not have enough running time to replace the energy that has been drawn from the battery during the period that the vehicle has not been running and during the starting phase, all while supplying the normal energy required for the running vehicle.  This puts the alternator in a constant high-output mode …. creating high heat.  This scenario is multiplied when the short trips also employ high vehicle electrical demands, such as; headlight use, climate control blower use, rear defroster use, heated seat use, etc.

* Degraded Battery - A battery that does not hold a full and proper charge will require the alternator to run at higher output levels (similar to the short trip points, above), resulting in consistent higher operating temperatures.

*  High RPM - An engine that is frequently run at higher RPMs will also spin the alternator at higher RPMs.  This generates more heat as well as accelerates wear on the bearings.

While the alternator is not a “lifetime” unit and can be expected to eventually need replacement, paying attention to the points noted above can help to extend the life of your BMW’s or MINI’s alternator.

* Fix any damaged or disconnected air cooling ducts.

* Take care of engine cooling system issues right away.

* Use a trickle charger if short trips with high power demands are a part of your BMW’s or MINI’s typical use.

* Replace the vehicle battery at the first signs of age (low voltage, losing charge while idle, etc.).

Check out the BavAuto online store at or give your Advisor, at BavAuto, a call at 800-535-2002 to assist in taking care of any of these issues …. or to replace a failed alternator.

Click image below for BMW & MINI alternators:

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How to Remove Stuck BMW or MINI Spindle Strut Clamp Pinch Bolt … Don’t Break It!

Jul 15 16

This article applies, in general, to all BMW models that use through-bolt spindle to strut (shock) pinch clamps, such as; E46, E90, E39, E38, E60, E65, etc. and all MINIs.

Dear Otto,

2003 325xi wagon

I just snapped the strut pinch bolt after soaking with penetrant and careful turning.  Looks like this could take a while.  Any advice besides drilling it out?  AND …. any advice on removing the other side?  It seems to be stuck as well.

Chris R.



At this point, your only recourse is to drill out the broken bolt section.  I’ll give you some tips on removing the other side, below. To drill out the broken one, start with small bits and work up to the larger sizes.  Use a slow drill speed and lots of lubricant (some type of oil) to both cool the bit and lubricate the tip. Do your best to get the initial drilling centered on the bolt shank.  Once the bolt is drilled out, you can either use a new longer bolt and lock-nut or install a thread repair insert like those from Heli-Coil, Time-Sert or others.  If this is done, you can use a new original bolt.

Alternatively, you can remove the complete spindle and strut assembly and take it to a machine shop.  The shop can quickly drill out the bolt shank and repair the threads.

How to prevent breaking a stuck (rusted & corroded) strut pinch bolt:

When you encounter a strut clamp pinch-bolt that will not initially move, to loosen, don’t continue to apply more force.  You run the risk of breaking the bolt or stretching it so that it will be more prone to break during our further removal attempts or may break or fail to hold torque upon re-assembly.  Proceed as follows.

Note that the procedures outlined here are no guarantee of successful removal, but they give you a fighting chance.

1) Heat the clamp ears where the bolt runs through, using a propane torch (Mapp gas works better as it burns hotter than propane).  If you happen to have an Oxy-Acetylene set-up, all the better.  Apply a penetrant such as Mechanic-All or PB-Blaster to all exposed sections of the bolt to clamp.  Apply heat again.  Re-apply the penetrant.

2) Apply a pneumatic impact gun to the bolt for just a few hits (“knockas”, to use the technical term) in both directions; clockwise & counter-clockwise.  Don’t over do it …. just a few hits.  Unless, of course, the bolt starts to move.

3) Repeat step #1 and #2.

4) Try loosening with a breaker bar …. remember; not too much force or you may stretch or break the bolt.

5) If the above steps do not produce results, you can continue repeating and wait a while for the penetrant to work into the bolt and clamp ears.  If no-go … continue to step #6.

6) It’s time to get a bit more serious at this point.  Use a pneumatic air hammer (air chisel) with a blunt hammer tip installed and hammer on the bolt head and the spindle’s clamping ears (where the bolt is going through).  Give it a good long shot with the air hammer, applying firm pressure to assure that the hammer is hitting good and solid.

7) Continue with all of the above steps until the bolt will begin to move.  If it gets too tight, after moving, re-apply the steps until it moves again.

Once the bolts is (hopefully) out, clean up the holes and threads in the clamping ears and seriously consider a new replacement bolt.  When reassembling, don’t forget to apply the Liqui-Moly copper anti-seize compound to the complete bolt threads and the shank.  This will prevent a future repeat of this scenario.

 Liqui Moly Copper Anti-Seize:

Mechanic-All penetrant & lubricant:

Replacement pinch bolt:

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