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Replacing the Hood Springs on a 993

by Bill Noble

This article is copyright W Noble, Oct 2002.  Permission is hereby granted to display and  print this article for personal non-commercial use only.  For permission to reproduce in quantity, or to use for commercial purposes, please contact the author at william_b_noble@IEEE.org .

Symptom

You open the rear of your car to add oil, and while your are pouring the oil in the rear deck lid closes on your head, or better still, pushes the oil container away from the little tube you are pouring oil into and spills it all over your engine. You go to open the front hood (for example, to take the car cover out) and you have to use a knife or other implement of destruction to lift it up.

If either of these apply to you, you need to replace the gas springs that lift the front and back hoods.

Rear Hood Springs

Let’s do the rear’s first – for two reasons: they wear out quicker (no doubt due to engine heat), and they are (believe it or not) a little easier to change.

First, a word of caution – the convertible (cabriolet) uses shorter springs than the other models – be sure you get the right parts.  There are some “heavy duty” gas springs with a lifetime warranty available, I have not tried these, and I would suggest caution – if the spring is too strong you may have unpleasant surprises.  The heavy duty gas springs are not available for the cabriolet (to my knowledge).

The original parts lasted me 4 years.  If you don’t drive very much, they may last longer.

Right Rear

The right rear is the easiest – so do it first.  Remove the air cleaner cover and the air cleaner element.  Have an assistant hold the hood mostly open.  Remove the clip and pin from the back (away from the firewall) end of the gas spring, and then remove the clip and pin holding the other end (the end near the firewall) – be very careful not to drop any parts, if you do, you will never see them again.  Install the new gas spring by doing the opposite – e.g. install the firewall end of the gas spring by pushing the pin through the spring and placing the clip back in place (being careful not to drop anything).  Then, attach the end that connects to the deck lid.  Note that the case of the spring is attached to the lid, and the piston rod is attached to the firewall.

Left Rear

The left rear is the same procedure as the right rear, except that there is nothing you can move out of the way, you just have to reach into the engine compartment and do it.  I found that reaching below the various obstructing parts worked for getting to the firewall end, and reaching above the parts allowed access to the deck lid end.  As with the right side, the body is attached to the deck lid and the piston is attached to the firewall.

Front gas springs

The front gas springs are larger, and access to the lower end of either spring is actually impossible, so you need some special tools.  Pictured below are the two special tools I’d recommend.  The top one is what I call a “grabber” – you will need this when you drop a part.  The parts are recoverable with a grabber (as opposed to the rear gas springs where any dropped parts are just plain gone) because they will fall into the enclosed body area.  And if you don’t recover them, they will probably rattle and drive you crazy.

The second tool is a flashlight with the bulb on the end of a flexible cable – the access is so restricted you can’t use a regular flashlight, get the beam where you need it, and still be able to use a tool.  If you have a really bright shop light, it might work, but I was working outside (the sun is a pretty bright shop light) and I still couldn’t see anything without a flashlight, and I couldn’t work with a regular flashlight.

Now Now that you have located the special tools, you also need a fairly long small bladed screwdriver.  3/16 seems about right, ¼ inch is too big, (that’s about 5 mm for you metric folks).  With this, we can start.

Practice Releasing the Clip

The lower end of each gas spring rides on a ball joint.  It is held onto the ball joint by a retaining clip that is released by sliding the 5mm screwdriver under it, as shown in this picture.  I strongly suggest you practice this 3 or 4 times with your new spring before you try and take out the old ones.  Just hold the screwdriver parallel to the gas spring piston rod and slide the blade under the clip (and if needed, twist a little).  Don’t go to far or the clip will spring off and then you will need to use the grabber to retrieve it, and you’ll need the flashlight to find it (ask me how I know this).

OK, ready?  Not yet.  We have one more step before you start:

 

Preparing the Clips

You will not be able to get the ball socket over the little ball if you don’t prepare the clip so it is open.  I do this by sliding the clip ever so slightly “forward” – e.g. away from the body of the gas spring.  See the picture below.  The clip in the picture is slid too far, but this is so you can see what you are supposed to do. Place your 5 mm screw driver under the clip and lift up on the handle so that you leverage the clip forward up onto ledge that forms the front of the ball socket – this will hold the clip open enough, and when you place the ball socket over the ball, it will snap back in place (if not, you can use a bent wire coat hanger to pull it up (toward the gas spring body) to make it snap into place.

Prepare the clips on both gas springs if you are changing both sides.

Now we are ready to change the gas springs.

Left side

The left side is the easiest.  Have an assistant hold the hood open.  Remove the plastic cover that is over the fresh air blowers – to do this, lift the rubber seal straight up and off of the sheet metal, and then pull the whole assembly (gently) forward.  Put it safely out of the way. 

Now, remove the small metal clip on top of the cover for the pollen filter.  Move the wires that are under the clip out of the way. Unscrew the pollen filter cover retaining nut (an aluminum knurled affair) and unclip the retaining clip on the far left side and remove the cover.  (Note – if you have a really long screwdriver, you may not need to do this step).

Now, push the pin that holds the gas spring to the hood towards the inside of the car, and remove the clip.  Then remove the pin.  Have your assistant move the hood up/down until there is no pressure on the pin so you can get it out easily.

Take your flexible flashlight and illuminate the ball joint – it is (of course) on the bottom end of the gas spring.

Then, release the clip on the ball socket (like you practiced in “Practice Releasing the Clip”).  Holding both the screwdriver and the old spring, apply force towards the centerline of the car and the ball socket will pop free.  Remove the old gas spring.

To install the new spring, first check that the clip is still in the “prepared” position.  Push the ball socket over the ball joint and verify that the clip snapped into the groove.  If it didn’t, use a bent piece of wire to coax it upward.  If it is in its groove you will not be able to pull the ball socket off of the ball joint (at least, not without a rather extreme amount of force).

Attach the upper end of the gas spring (having your assistant raise the hood so you can get the top of the spring into it’s slot, and then lower the hood until the holes for the pin line up).  Insert the pin and attach the pin’s retaining clip.  You may elect to put a little grease on the pin – the factory seems not to have done this, and so the pin does show wear.

After the spring is properly connected, replace the pollen filter cover – be careful to line up the various groves – when you get it right it will slide smoothly into place.  Place the wires back where they came from and replace the metal clip that holds them in place.

Right Side

The right side is replaced using the same procedure, with the following additional steps:

  1. There is a wiring harness that goes over the top of the pollen filter cover.  There is a plug on the side of the pollen filter cover.  Unplug the harness at this plug.  Slide the part of the harness that was attached to the cover up and towards the center of the car to release it from the cover.
  2. There is a plastic sleeve that prevents the gas spring from chaffing against the wires that are near it.  This sleeve is in the way and can be pulled upwards towards the gas spring body so you can see and release the clip that holds the ball socket.
  3. Don’t forget to put the plastic sleeve back on the new gas spring before you install it.

Addendum

This is an excellent suggestion from someone who read the above procedure.  Thanks Marc for the great idea

> Bill,
>
> I finally got around to changing my rear deck lid shocks on my 993.  
> So I read your DIY article and I decided to tackle the job.  For the 
> right lid shock, once you remove the air box, the job is pretty 
> easy.  Just reaching back into the engine requires more feel and 
> directed light than anything.
>
> However, when you go to replace the left shock you said "the left 
> rear is the same procedure as the right rear, except that there is 
> nothing you can move out of the way, you just have to reach into the 
> engine compartment and do it."  Well, it took me 15 minutes to remove 
> the read blower motor and a couple of attached hoses and the left 
> shock was just as easy to replace as the right.  Did you try this 
> approach?  If not, it makes the job a whole lot easier.
>
> Just thought I'd share that with you in case you didn't know.
>
> Sincerely,
>
>
> Marc Gianzero

This page updated 07/14/2021