Strut and shock replacement on mk3 VW Jetta and Passat TDI

Nov 10, 2013
Strut and shock replacement on mk3 VW Jetta and Passat TDI
  • Shock and strut replacement on a mk3 VW Passat TDI
    Difficulty: 3/5(due to special tools required and rusty bolts)
    Back to the jetta/passat FAQ and "how to" index page


    Introduction

    This article shows how to replace the struts and shock absorber on your mk3 VW Passat or VW Jetta 1996-1999.
    Shocks/struts, springs, and other suspension
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    bushings and mounts were not meant to last forever. Carrying heavy loads, rough roads, or a damaged shock/strut boot may cause the suspension to wear out faster than normal. If you want to return to a like-new ride, replacing these parts will help. However, to fully restore your suspension to new levels, you should replace all of the suspension bushings in addition to the shocks, springs, and mounts. Shocks/struts, springs, and other suspension bushings and mounts were not meant to last forever. As a rough test of strut condition, push down on a corner of the car. If it bounces and returns in one or two bounces, it is probably in good shape. The second bounce should be a lot smaller than the first. Also look at the shock/strut damper piston. If you can see the metal piston, consider changing the boot because the boot serves to protect the seals from dirt. Your VW TDI came stock with gas dampers. If you switched to liquid shocks, check for pooled or a noticeable amount of liquid around the shock piston which indicates bad shock seals. The OEM Boge/Sachs shocks are vilified because they're soft but their construction quality is good. But because they're so soft and combined with worn bushings, worn shocks result in a poor ride.

    Note that shock/strut/damper are often used interchangeably. A damper is any "shock absorber". A strut is a damper that replaces the upper suspension arm and normally carries the spring. This is called a McPherson strut and is what VW uses. A shock is normally just the damper. Struts do not control the ride height unless the perch is different from stock. The springs carry the weight of the car and control ride height, the struts just dampen the motion.

    The passat sedan, passat wagon, and jetta shock/strut replacement are all about the same. However, in the passat station wagon, you must remove some interior trim to get access to the strut upper retaining bolts. The jetta's strut is mounted slightly differently. This article will show strut replacement in a passat wagon, differences are noted.

    Here are some brand/models that people have been happy with in the past but remember that ride quality and harshness are highly subjective! Someone's soft ride may feel hard to you. Sporty to one person may be "kidney bruising" to you. Brands that many people are happy with are Bilstein, Koni, and Monroe. The Monroe sensatracks are said to be comfortable. The Koni reds are a premium stock-like ride, the koni yellows are a sport-ride and comparable to the bilstein HD. The Bilstein TC (touring class) shocks are an economy twin tube design and is a "close to OEM but stiffer" ride. The Bilstein HD are a stiffer monotube shock and a good choice for a sportier (stiffer and rougher). Both are for stock height suspensions. There are also TC sport suspension, which are designed to be used as replacement with the sport suspension. These are a lowered design and to be used only with lowered or sport suspensions, these are N/A for the mk3. I avoid the OEM VW sachs or boge replacements because they are more expensive and softer than the TC touring class shocks. For the Mk4 cars, many people say that the Bilstein TC shocks tend to be harsh, especially in the rear. Most people do not experience this with the shocks for the Mk3 cars, probably because of the 14" wheel instead of 15" wheels and different springs. Tire sidewalls are an important part of the suspension, taller tire sidewalls (higher aspect ratio) will dampen more than thin short sidewalls.

    This is also a good time to inspect the brakes, anti-roll/sway bar bushings, and lower control arm (LCA) bushings, in that order of priority. The sway bar bushings are worn out by 100,000 miles and should be replaced as needed. A symptom of bad sway bar bushings is a clunking noise from the front when you go over small bumps and potholes. The LCA bushings are the same part across the mk3/mk4 TDI and Audi TT except for the early Audi TT bushings which were discontinued.

    Your car will need an alignment after strut replacement.

    CAUTION - do not put the jack stands on the suspension or rear axle. This can act like a fulcrum and cause the car to fall down. You need the suspension to be able to move while you work on it. Always use the factory jack points as specified in the service manual. This page has pictures and tips only and does not supercede the factory service manual. See the TOS Agreement for the full legal disclaimer.

    Feel free to sign up and ask a question about this article at the forums here: myturbodiesel.com forums

    Parts

    7mm allen wrench for counter holding OEM strut with 21mm nut
    torx sockets if using bilstein struts for counter holding bilstein 22mm nut
    17mm wrench/socket for the lug nuts and caliper bolts
    18mm wrench/socket for the lower strut nuts
    21mm and 22mm deep offset box wrenches, a 21mm and 22mm pass through wrench such as the gearratchet, metalnerd specialty tools VW/Audi suspension special tools, or VW tool #3186 NOTE: 21mm is for the bilstein strut nut, 22mm is for the OEM VW nut. A 13/16" spark plug socket will also work if it has a way to hold it from the side.
    metalnerd also sell a tools for counterholding the strut : metalnerd MN2122 strut counterholder VW tool #3186 is not recommended if using aftermarket struts since they use different sized nuts.
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    2 spring compressors (1 set) - these can be rented from autozone for free
    Pair of shocks/struts. Note: always replace in left and right pairs, preferably front and back as well.
    strut mounts and bump stops
    dust boots for the shocks
    new strut bearings for the front struts

    Related links

    1000q: mk3 passat wagon trim removal1000q: front disc brake job, for mk3 passat & jetta
    1000q: rear disc brake job, for mk3 passat
    1000q: rear drum brake job, for mk3 jetta
    1000q: soundproofing your car
    1000q: garage organization and mechanic's tips

    Front strut replacement procedure
    If this is for a passat station wagon, you can either try to pry out the trim or remove it all for easier access. If you don't want to remove the trim, read this article thoroughly and the station wagon trim removal writeup : 1000q: passat wagon trim removal and you should be able to figure how to to avoid removing the trim. If you can't figure it out then remove the trim. I prefer to remove the trim so that soundproofing can be added at the same time. For all other models, just open the trunk and fold down the seats to get access to the rear struts.

    To remove the rear struts, first examine the below pictures. The rear seat belt retractor covers the upper strut nuts. The retractor is held in by (1x17mm) bolt, circled in yellow, remove the bolt and retractor. This is why it may be easier if you remove the trim: there are (2x17mm) bolts, locations circled in red, that hold in the rear shock and it is hard to access the rear one unless you remove the seat belt retractor, which you remove the cover, which is easier if you remove the rest of the trim.

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    Engage the parking brake, jack up the car using the factory jack points and as recommended in the factory service manual, rest car securely on jack stands, chock the front and/or rear wheels as necessary, and make sure the car is safe and secure before doing anything else. CAUTION - do not put the jack stands on the suspension or rear axle. This can act like a fulcrum and cause the car to fall down. You need the suspension to be able to move while you work on it. Always use the factory jack points as specified in the service manual.

    Each strut is held in place by 3 bolts/nuts. The rear is held by 2x 17mm upper bolts, 1x 18 lower nut/bolt, the front by 1x 22 upper nut, 2x 18 lower bolts. Remove as necessary.

    Rear shock replacement
    Below is a passat rear lower shock, strut outlined in yellow. Remove the lower 1x 18mm nut/bolt and the 2x 17mm upper bolts. There is also a plastic clip at the top. The lower bolt may be rusty so soak it in PB Blaster beforehand to loosen it up. You can also use a torch to heat the seized bolt.
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    Remove the entire strut/spring assembly from the car before compressing the spring. The springs are not under tension against the car body, they are under tension against the spring seat at the top of the strut. (front is pictured below, rear is similar). Once the strut assembly is out of the car, use 2 spring compressors on opposite sides to compress the spring. It should look like this. Lubricate the threads with WD-40 or grease so that there is less resistance to tightening it.

    CAUTION: Be careful when using spring compressors since any failure or slipping could result in the sudden release of the spring, strut, or other stuff on the assembly! Don't stick your hands near the springs while the springs are being compressed! You could get pinched or the spring compressors could fail! Always point the spring and strut away from yourself so that if it does fail, it doesn't hit you! I use an air wrench to easily tighten the compressor bolts. If you don't have a spring compressor, they can be loaned at many auto parts stores for free. Then remove the nut holding the upper spring seat. The spring will then come off and you can then put the compressed spring onto the replacement.
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    Note the assembly of each strut before disassembling. For the rears, it goes: plastic cap, (remove with screwdriver pry), o-ring, strut nut, metal mount, rubber mount, strut mount (with foam gasket, it's best not to try to remove it), rubber mount with metal tube, metal cap, washer, bump stop, as seen below. Note where the spring seats against the lower spring seat.

    Reassembly is the reverse of removal. Do not use the nut at the end of the strut to compress the spring because this can damage the bearing or crack the bearings or set the nut to the improper torque! You must compress the springs with the spring compressor and then use a torque wrench to tighten the nut to the proper torque, and then release the spring compressor. Double check the spring position against the bottom of the strut after releasing the spring compressors. You may have noticed painted dots on the spring, these are color codes to identify spring rate.
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    NOTE - when replacing and tightening suspension components, always do it in the weighted position. This means that the normal weight of the car should be loading the suspension. The suspension and shocks should be in the middle position - not fully extended and not fully compressed. You can place a jack under the suspension arm to load the suspension, just make sure to not shift the car off the jack stands, and do not compress the suspension arm all the way up.

    Front struts
    Below is the passat front lower strut and wheel hub. The strut can be slid out towards the engine, just push the strut in the direction of the arrow. Counterhold each nut bolt/while loosening the other side. If you find that you don't have room to get the strut assembly out, just compress the springs a little and push down on the suspension arm. Make sure the car is secure while doing this and any other work on your car.
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    You can use an impact wrench to blip off the 22mm upper nut but don't use an impact wrench for installation!

    The issue is that the nut must be counterheld against the strut shaft with a 7mm allen wrench or else it will just spin. You can use a deep offset wrench, a pass through wrench, the metalnerd MN2122 strut counterholder (pictured again here), or VW tool #3186. I prefer to use the "gearwrench" pass through wrench because it can use both a 21mm and 22mm socket among other sizes.
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    The advantage of the metalnerd tool is that it has a square cutout for adapting a torque wrench (always mate at 90o angle!), is cheaper than buying a new wrench set, and works. It also has both 21mm and 22mm ends for OEM and aftermarket struts.

    Below are two views, of a gearwrench, a pass through wrench that lets you stick an allen wrench through it. The third picture shows a wrench with a torx tip going through a spark plug socket that is held with a wrench. If you don't counterhold the shaft then the nut and strut will just spin. Again, you could use an impact wrench to loosen the nut but do not use an impact wrench to tighten the nut!
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    Here is a 13/16" spark plug socket, just remember that some aftermarket struts may have a different size nut.
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    Here is another idea - two nuts tightened against each other can counterhold the shaft - my VW strut did not have enough threads to do this and I had the tools.
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    Reassemble as necessary. Do NOT use the nut at the end of the strut to compress the spring. You must compress the springs with the spring compressor and then use a torque wrench to tighten the nut to the proper torque, and then release the spring compressors. Otherwise, you could damage the bearings or set the nut to the improper torque.

    For the fronts, it goes: top cap, nut, rubber mount, nut, front strut bearing, bump stop, dust boot. Again, note the dots on the springs and their orientation to where the spring seats against the lower strut spring seat! The dots are color codes to identify spring rate.
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    Double check that the spring is still seated properly against the strut after releasing the spring compressors as it may move when releasing the spring tension. The end of the coil has a matching indentation in the spring seat that it must be snug against. Releasing the spring compressors may cause it to shift. If it does, just recompress the spring and adjust.
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    All done? Double check the lower struts nuts are tightened to their proper torque (70 ft lbs x 2 bolts and nuts) and get an alignment. The struts serve as the suspension uprights and your camber will be off. You may want to drive around for a day to let things settle in before getting an alignment. If you don't know what your camber spec is, read: 1000q: tire alignment index. For tips on how to use a torque wrench, see 1000q: torque wrench FAQ.

    Final note:

    You may notice the front strut rubber bushings and stops higher are than they were before. As long as you are sure that they are properly torqued, it is fine. When your VW was new, there was about 1cm of play at the top of the bushing mount. Due to age and the car's weight resting on the springs, the springs sag and increase this space. New rubber bushings and stops will decrease this height. Note that the new strut upper bolt may be taller than the old bolt, so this may also raise the height of the upper mount. In any case, the upper mount is designed to hold the strut from falling out and some play is normal.

    Test drive the car and double check all bolts, then get an alignment!