Monday, September 3, 2007

Step 12: Attaching Heavy-Duty Rear Shocks

Description: Replacing the old shock and strut springs with a heavy-duty variety.

Tools Needed: Strut Spring Compressor (If you're game - see caveat), Wratchet and torque wrenches. Two 10 inch plus adjustable wrenches. Rubber spacers (or homemade varieties). New heavy duty strut springs and shocks.

Estimated Time: 3 hours.

Caveats: Electro Automotive warns against doing the struts yourself, instructing you to bring them to someone with the right tools - skip past this part if you take their advice. I did it myself, so I'll go through how I did it, but accept no liability either. Also, make sure you jack the control arm up before removing the shock, as it is the only thing holding the control arm up.

Purpose of this step: Since the addition of the 20 lead acid batteries will add well over 1,000 pounds to the car, heavy duty shocks are needed to handle that extra weight. The same is true for the front shocks, which I will add later.

This is probably a good time to do this step, although the manual has it later on. It allows you more breathing room under the car. Here is a picture of the old shocks and strut springs still in the car:

The whole shock and strut unit can be removed in one piece. The first thing to do is jack up the car and remove the tire.
The reason for this is to give you access to the nut holding the spring in. You can then turn that nut while holding the bolt head on the other side. You need two good size adjustble wrenches (or the right size regular ones if you got 'em).
You can unscrew and remove the nut and washer, but do not remove the bolt UNTIL YOU'VE JACKED UP THE CONTROL ARM. Otherwise the control arm will just drop when the shock is not attached. I would also stray slightly from the instructions here and suggest loosening top bolt before removing the lower bolt if you are doing this by yourself, as you will need to remove the shock from below. The top screw is under the rubber bumper in the rear trunk:

Once you have the top screw and the bottom bolt out, you have the whole strut and shock in one piece.

You will then need some nuts, washers and rubber bushings from it for your new shocks, along with the top and bottom spring retainer. Here is where it gets a little tricky. You can't just remove them from the old shock, because the compressed strut spring would fly off, potentially causing serious harm to person or property. You can take it to an auto shop and let them pull off the parts needed and attach them to your new strut and shock and skip the next part, but I decided to give it a go.

I got a strut spring compressor from AutoZone. They sell for 40 bucks, but you can take one out for free with a deposit. I believe a coil spring compressor would also work.

This will compress the spring so you can safely remove the spring retainer and other needed parts (you need to compress both sides or the spring will bow). After removing the spring, you can loosen the compressor to remove it from the extended spring. I should note that the spring actually extended farther than the compressor, slightly, but I was able to remove it with a slight bit of manual compression on the spring.

Here you can see the difference between the old (black) strut spring and the new (cool blue) strut spring, which is shorter and has thicker coils.

They can be added to the new heavy duty shocks with the same compression technique and the screws and retainers from the old shocks. Because the shock is shorter, it didn't need much compression. (If I did it right) It should look something like this:

One problem is that the bottom two sides of the shock would seem to require rubber spacers before attaching them to the control arm. They were not supplied with the shocks, presumably because they assume you would use the ones from the old shocks, but those aren't compatible.

I ended up trolling the local auto parts stores. There is no standard rubber spacer. At Napa I found something I figured I could fashion into a spacer by cutting off the ends and carving it a bit to fit.

Here's what I came up with in the end. I think it works alright. I guess sometimes you have to improvise.
Finally, I put in the new strut, screwing the bottom bolt and nut and then the top nut (they give you a new top nut for some reason). Here it is in the car:

It is the same procedure on the other side. I should note that these are not adjusted with the precision needed. Once I get the car running, I will need to go to the shop and have them balance them precisely, although I should at least be able to drive on them to get to the shop.


Richard Krog said...

I have just completed these same steps for my 914 conversion. I was lucky in that I had a second set of the bell-shaped retainer that sit on the top of the coils, so I didn't have to mess with any coil-compressors. Compared to the nightmare of replacing the front suspension, the rear was a cake walk.

I'm not sure what you mean by having the rear suspension balanced . I don't see anything that is adjustable in the rear suspension like you have with the front torsion bars. I just bolted them in and was done.

Thanks for posting the information about the rubber spacers. I simply bolted the bottom end of the shock assembly to the control arm, but now that I look at your solution, I'm thinking of doing the same.

Drop Suspension said...

These are excellent steps to follow for installing a suspension system. I really thought this is very helpful. I've had trouble doing it so by my own. Thanks!