VW SuperBeetle Shimmy (aka DEATH SHAKE): A Serious Problem — Not Just a Minor Annoyance!
In 1971, Volkswagen introduced the VW Super Beetle (aka: Model 1301), billing is as a nicer version of the tried and true Standard Beetle that had been used for over 50 years! The Super Beetle had a totally re-designed front suspension, which featured:
- A Better Ride (quieter and smoother)
- A 50% Larger Fuel Tank
- Much Larger Trunk (almost 2x as large!)
- Tighter Turning Radius (because there is no axle beam in the way restricting the front tire turning angle!)
The Standard Beetle had a rigid axle beam, with torsion leaves (Springs) that were twisted inside each tube of the axle beam. These tubes and leaves ran across the front of the car. Unfortunately, this design cut right through the trunk and gas tank area, which is why the trunk and gas tank were so small.
In the re-design of the front end, VW went with Macpherson Struts, which is a compact coil spring and shock absorber in one unit. This design is still used today on hundreds of car models, because the strut (spring) does the job of car support, and the strut insert (shock) does the suspension damping, very well while placing it in a location that is out of the way. But for our beloved Beetles, the early use of the Macpherson Struts were accompanied by a complex suspension and steering design, with around 2x the parts as the Standard Beetle (and Karmann Ghia). When you have 2x as many parts, that’s twice as many things to wear out and break! And all cars have parts that wear out and break! But most Vintage VW Owners are either super cheap, or don’t care (it still runs, so what is the problem?).
The VW Super Beetle front suspension design is very sensitive to parts being worn out. And most Super Beetles have more than just “one” part worn out in the front end! Worn out parts in steering and suspension means the system(s) have “play”, where parts can move and are not restrained (controlled). This is the recipe for the “Super Beetle Shimmy” (AKA: Super Beetle Shake). So in this article we are going to lay out for you what you need to look for, and what you need to change, to make you more knowledgeable than most “VW Mechanics” out there that claim to be able to fix this annoying and dangerous problem.
Typically the “Super Beetle Shimmy” will show up as a front end shake in the 40-50mph range, typically it’s worst at 45mph or so. This shake can be very minor, or REALLY BAD! Basically you can think of the front end as a series of 8-10 parts, and they need to be firmly connected to one another, while being able to move about. If any of these parts has “free play”, then at one end of the system it can be held firm, while the other end of the system parts are free to wiggle about. Another note is that if you have play in the system due to a worn part, this play will often wear out OTHER good parts in the system much quicker, since they are getting vibrated and pounded into submission by the shake! And as discussed earlier, this shake can be quite violent.
We found a great Youtube video by a clever Super Beetle owner, who figured a way to mount a video camera underneath his Super Beetle front suspension, in order to figure out what was causing his Super Beetle Shimmy. I want to make some quick comments for you to follow as you watch his video.
First, he has his lantern fuel filter mounted in a great place! Under the fuel tank, where it’s relatively easy to see if it needs replacement, and where it’s safe from catching the car on fire if it were to leak! Fuel filters in the engine compartment are an engine fire waiting to happen!
Secondly, he has an exhaust leak, or a cylinder head is coming loose. You can hear this every time he accelerates, the first indication of this is from 0:33-0:35. You can hear it at other points in the video, just listen.
The third thing I noticed is that at 0:27, that movement alone means that Lower Control Arm Bushing is SHOT!
You’ll see a hint of the shake at 0:46 as he’s coming to a stop, but you can see how bad it gets at about 1:00-1:23 in! How are the tires supposed to be “aligned” when parts are moving around like that? The job of that bushing is to allow the arm to pivot around that bolt, but not move up/down nor side/side. EPIC FAIL! Bushing is shot!
The owner of this car states in his comments that the bushings were replaced just 6 months prior to this video being taken. The Lower Control Arm is connected to the frame head of the chassis (floor pan) on the inboard end, and at the bottom of the Macpherson Strut at the outboard end via the Ball Joint. The job of the Lower Control Arm (LCA) is to locate the bottom of the strut, so it cannot move left to right (in/out). The bushing in there to provide a little bit of “give”, so that the car is relatively quiet.
There are 3 “types” of bushing being sold out there, Rubber, Urethane, and Metal. Urethane ones are usually excellent, and nowadays we feel they are always better than rubber! Urethane is very firm, and do their job well (allowing a pivot without deflection). Metal bushings are only used in a select few applications (not including the LCA Bushings). To further complicate things, the Rubber ones are available in 2 types, Genuine VW, and “Aftermarket”. The Genuine VW bushings are excellent (Identified with the VW logo and VW Part Number formed onto the rubber), but they can be difficult to find (even some VW dealers sell non-VW bushings, because VW dealers are franchises, and even those owners are trying to maximize profits wherever possible). The aftermarket rubber bushings ARE NEVER EVER TO BE USED, EVEN WHEN THEY ARE BRAND NEW! The aftermarket bushings are far too soft, and the LCA is not held in place by a bushing that is as soft as taffy. The LCA moves around like crazy (like in that video), so the bottom of the strut moves around like crazy, and so the wheel and tire move around like crazy. SHAKE, RATTLE, AND ROLL!
Remember, we do not want ANY play in the system!
Understand that just because the bushing is shot, doesn’t mean the bushing caused the problem. If this guy was driving around on unbalanced tires for 6 months, all the parts were subjected to a serious beating, and no rubber bushing is going to take that for long. Understand that any Super Beetle is 25-35 years old, and the critical suspension and steering parts may have been beat up and worn out 4-5 times already! And then you have the problem of Previous Owners (POs) that changed parts with cheap ones, or ones that didn’t work, even if they thought they were trying to help! And if you have a car that hasn’t been driven for a few years, even if the bushings were new when the car was parked, there is a good chance they are shot now just from old age! Rubber deteriorates with age!
Note that there are 2 types of suspension, 1971-73 1/2, and 1973 1/2+.
- Early strut (3 bolt, with 3 bolts connecting the Strut Housing and Ball Joint, sandwiching the Spindle), and
- Late strut (2 bolt, with 2 bolts connecting the Strut Housing and Spindle).
Also note that there are 2 types of steering,
- 1971-74 with a steering box, idler box, and 3 tie rods.
- 1975+ with a Rack & Pinion.
So when you combine the 2 types of suspension, and 2 types of steering, we wind up with 3 types of front end.
- 1971 – 73 1/2 (3 Bolt Strut, 3 Bolt Ball Joint, with Steering Box and Idler Arm)
- 1973 1/2 – 74 (2 Bolt Strut, 2 Bolt Ball Joint, with Steering Box and Idler Arm)
- 1975+ (2 Bolt Strut, 2 Bolt Ball Joint, with Rack and Pinion Steering)
The 1975+ R&P system simplified the steering a LOT, by eliminating a ton of wear-out parts to wind up with a steering system that was vastly simpler, lighter, and more reliable. Yes the R&P is expensive, but you don’t get nickle and dimed to death with 2 more tie rods, 4 more tie rod ends, a steering damper and bushings, an expensive steering box, and idler arm box and bushings.
So now that the basic overview is covered, we are going to help you figure out what is wrong with your car! You’ll need a partner to help you figure out where the play is, then you’ll know what needs to be replaced!
You will be checking parts while the car is on the ground, and while it’s jacked up and safely on jack stands. Sometimes a part will “check out fine” while in the air, but not on the ground, and visa versa. This is why we need to check under both conditions.
Basically you are going to run your hand on these parts, and feel for play or “wiggle”. Wiggle/play is BAD. Remember, the system needs to be firmly connected, while being allowed to pivot and/or rotate.
While your partner is “wiggling” the steering wheel, feel for play in all steering joints.
- Steering Damper
- Pitman Arm Bushing (small bushing Steering Damper is bolted to on the steering box)
- Tie Rod End(s) (there are 2 on R&P cars, but 6 on Steering Box cars (1 on each end of the Left Tie Rod, Right Tie Rod, and Center Tie Rod)
- Steering Box (remember, movement in and no movement out means it needs to be adjusted or replaced)
- Idler Arm Bushing (the mirror of the steering box, on the passenger side). The Idler Arm holds the passenger side of the Center Tie Rod.
Now you need your partner to grab the top and bottom of the tire, and really crank on it. You are trying to twist the bottom of the tire out and top of the tire in, then top of the tire out and bottom of the tire in.
Feel for play in these locations
- Brake Drum/rotor (indicating wheel bearing issues). Feel for play between the drum/rotor and backing plate. If one wheel bearing is bad, replace both on that same drum/rotor, since metal from the failure of the first bearing will contaminate and wear out the other one on the same wheel!)
- Lower Control Arm Bushings (where the LCA bolts to the frame head, the spot where that video above highlighted). These are the most common source of the Super Beetle Shimmy
- Ball Joints (the outer end of the LCA, on the bottom of the steering spindle, the ball joint has the rubber boot on it, with the threaded stud and nut sticking downward)
- Strut Bearings (At the top of each strut tower, inside the trunk). These should pivot/rotate, but not wiggle side to side nor up/down.
Now put the car back on the ground. Have your partner grab the top of the tire, and start pushing and pulling it to get the car to shake side/side. This oscillation will simulate the loads we need to identify bad parts. Re-check for play, the same items as above. Note that this is putting the parts in the loaded condition of driving, so it’s possible parts will pass the first test, but fail this second one! If it fails EITHER the part is in need of replacement.
Also see if you can push/pull the wheel fore/aft, and feel for play both where the threaded rear part of the Front Sway Bar goes into the Lower Control Arm. If the arm can move on the sway bar end, the bushings are shot. Lastly, check that the sway bar is not wiggling where the front of the bar is bolted to the frame head of the chassis. If EITHER of these are bad, replace all the Sway Bar Bushings with urethane ones! The sway bar secures the bottom of the wheel (strut) from moving fore/aft, and the LCA locates it side/side.
Now bounce on the front of the car, the fender or bumper. The front should immediately go back to “normal” without oscillation/bouncing. If it does, the strut inserts are bad and in need of replacement. Strut Inserts are just shock absorbers for the Macpherson Strut.
There is also a steering universal joint beneath the fuel tank, but this can only be accessed by removing the fuel tank. Just know that if the steering wheel is wiggling and you do not feel and motion at the input of the steering box or R&P unit, the steering universal joints are bad and need to be replaced.
Now that we have gone through all the components, and you have those parts ordered and on the way for you to replace them, we STILL have checking and work to do. If the wheels and tires are perfectly straight, and perfectly balanced, even if there is play in the front end, the car will behave properly (for the most part). The reason it starts shaking is that we have wheels and/or tires that are NOT straight, NOT round, and/or NOT balanced!
It’s important to grasp that a wheel and tire can be perfectly balanced, but shake bad on a car. What if the wheel/tire is not round? A wheel/tire can be perfectly balanced but not be round, and it will shake like crazy. Or what if the wheel lugs are NOT in a perfect pattern on the drum/rotor? You have a straight tire/rim that is mounted slightly off center, because the guy drilling the drums/rotors was not paying attention. Or a tire cord has snapped, and it’s balanced by has a lump or bubble? Or how about a situation where the wheel and tire are perfectly straight and balanced, but the rotor/drum is out of balance? Some tire shops have the tools to balance the tire ON THE CAR. This balanced the wheel, tire, AND drum/rotor so they are silky smooth. Balancing the tire and drum/rotor on the car is better than off the car, but not many shops have this equipment. Just remember, balanced isn’t necessarily round, and round isn’t balanced, you have to have both conditions perfect to have a chance of a shake free ride!
Some car owners that have a shake in the front, find they can tune this shake out (after having tires and rims balanced) by re-indexing the wheel. Note that on a 4 lug car the rim/tire can go on 4 different ways. Some ways may make the shake worse, some better. When you have your tires balanced, make sure you tell them to check the wheels/tires for runout (wiggle), and out of roundness. Don’t be surprised if you have a rim, 2, or even all of them, that have problems. A lot of brand new wheels (cheap, low end wheels) have manufacturing defects, and the wheels are simply not round (but they may be pretty!). They either rotate in an eccentric, or wobble. Either of these situations is going to create an oscillation that will cause a shake.
Remember, this car is ~40+ years old. All it takes is one guy parking the car to hit the curb, and tweak the rim a little bit, and now the rim is no longer straight. It will wiggle while it’s spinning. Even if it’s still balanced you are going to have a steering wheel shake with this condition.You can also have rims/tires that are not round, they are egg shaped. This will destroy the shocks or strut inserts very quickly. Periodically you’ll see cars on the highway where the wheel is bouncing instead of just rotating. This is usually a bad shock and an out of balance tire, and if the shock isn’t bad it will be in under a week!
Know that you may have to experiment with swapping tires from front to rear, or with all 4 different mounting orientations. But I would not bother with this until you have the tires checked for being round, straight, and balanced. It IS worth the money to get a good balance job done on your wheels.
Another last point; make sure your front tires are not inflated past 24psi. Over-inflation is a common mistake, and the cause of a lot of shakes and rough ride.