rodneyr

Well, I was looking into changing the rear shocks since I need more dampening over bumps. I thought about putting on a new set of Bilstein Sport shocks would do the trick. Car is just a street weekend car when the weather is nice, and don't need high performance.

In theory, the installation should be really easy in only a few steps - remove the bolt on tower mount, support the trailing arm and remove bolt from bottom of shock - put in new shock and repeat for the other side.

Do you need someone to hold the shock from turning when loosing the bolt on the tower mount? I am guessing I would need a long wrench to be able to get leverage to loosen the bolt on the tower.

Can I just replace the rear shocks without causing balance or other issues with the front suspension or would I need to change anything else?

Finally, I can see the tower on the left side, but can't see it on the right. Do I have to remove the air box or just dig my way around the insulation on the right side in the rear? (see picture)

Any guidance would be appreciated.

porsche0nut

For access, I would take the few minutes to remove the heater blower and associated ducting on the left side and the airbox (and ac compressor if you have it on still) on the right side. Access will still be fun since they're way back there!

As for dynamics, anytime you stiffen the rear relative to the front you will reduce understeer and increase oversteer, all else being equal. As for the relationship between front and rear for rebound, I'm sure someone else with more knowledge will chime in! My thinking is that the softer front will help weight transfer to the front of the car on turn in... But may also make the front end more twitchy over bumps as it will take longer to settle than the rear with softer shocks up front?

Amber Gramps

Shock rods have a variety of tips that range from flat sides on the exterior to allen head key holes.

I will typically use a socket or allen key on the rod itself and a speed wrench (ratcheting box end) on the nut. If you have access to air tools you can usually hit the nut with a deep impact socket and blast it right off.

Bilstein Sports are the way to go. I did the HD's and they were useless. Switched to Sports, then re-valved Sports, then coil-over Sports, then...well, you get the idea. Heck, I've got a pair of HD's with 5,000 miles on them sitting here collecting dust. Not worth the effort to install. Go directly to Sports.

Installing the bolt into the bananas is the tricky part. It is imperative that you align everything up correctly or you will strip out the threads in the bananas. Put the car on jack stands so you can use your jack to adjust the height and angle of your bananas.

rodneyr

So, I am guessing there is no way around not having to take off the air box and more on the right (passenger side)?

I did try to access the left side tower with a wrench and that is not bad - I did not really try to take it off, but at least I know I can reach it.

Amber Gramps

You do not have to take off the entire airbox, just remove the filter cover.

Warehouse33.net

I think the favorite on the 911's is Bilstein HD struts in front & Sport shocks in back. Like amber lamps said you should just be able to remove the cover.

-Jason

theiceman

i have Bilstein sports all round and love them .

911 Rod

I found they were too much shock for my stock bars and mine are thicker than yours.

PelicanParts.com

This tech article on the 911 shock replacement should help answer all your DIY questions.

-Luccia

rodneyr

Well, I completed the rear shock install. Lets say the first time is a royal pain learning to get to everything.

The right side is the most complex because of the lack of room to move around. You can't even see the bolt (top of shock) without moving the hoses away.

I did have a lift and that helped a lot to support the control arm and take weight off the shock and for adjustments to height of car to line everything up.

Step 1 - Remove the Air box & Filter -- no tools required. This is when I realized there are 4 clips (2 in the back) and undoing the rear ones can be a little tricky. Reaching the bottom back clip to put the box back on is difficult. If your arms/hands are too big I don't see how you will be able to get far enough to put the clip on.
Step 2 - You need to use a socket or something to stop the rod (top of shock) from spinning before you try to loosen/tighten the nut. For Bilstein Sport you need an allen 5mm on a socket wrench. I went around the left/back side of the air box which was difficult. On old shock had to use a vice-grip for top of rod. No regular socket would fit.
Step 3 - 17mm speed wrench in right hand while holding socket wrench in left hand. Without speed wrench you are in for a long workout. I had a helper. We would switch off from the speed wrench (right) & allen socket (left). Your left arm is elbow deep in the car and is uncomfortable. Also, it takes a lot of turns on the speed wrench and is difficult to keep it in the right place because of the hoses in the way and angle of the tower.

Look at the picture and you will see several hoses in the way and will not be able to see the bolt on the top of the shock.

Once you finally get the nut off the rest is pretty straight forward and putting in the replacement is basically the same process. The left side is easier because you have more room on top and the sides. We were even able to use a power tool to get the nut off, but not to put it back on because of the spinning rod.

For only a top and bottom bolt the process is difficult and would be very difficult for 1 person.

Spyerx

Having just gone through this, it is a pain in the butt. I used vice grips to grab the top of the Boge oem damper. I used a long 5mm allen and turned it to brace against firewall to tighten. I used zip ties to pull the hoses up out of the way, removing the bracket attached to the air box. Gave a lot more room.

Fronts are easier, just messy.

ron mcatee

An impact wrench is the only way to IMHO. Make sure the threads go on correctly, spin the nut on.

rodneyr

Spyerx - Zip ties are a really good idea. I wish thought of that. You really need to force the hoses to get them out of the way. I probably had the OEM Boge shocks and had to use a vice grip because a regular socket is not designed to fit. The shocks were so dirty I could not even tell the brand. One of these days I will clean them just to see what I have. Of course, they were dead and have no idea how that did not get picked up in the PPI. On a smooth road there was not an issue, but on an uneven surface it was like going to a dentist.

Ron - we had an impact wrench and I don't see how you can use one and keep the shock rod from spinning. Like Spyerx said you need to hold the top of the shock so not to sure how to do both at the same time. Plus not much room at all on the right side for impact wrench. That said I was able to use an impact wrench on the left side to get most of the nut off on the shock I was pulling out. I did not work to tighten because the rod just spun.

This is definitely an exercise of patience and will.

On a positive note, the new shocks improved the dampening of the car and it does not "bounce" in the rear over bumps -- it is a little stiff, but OK. Maybe sometime in the future I will look at the front suspension, but it is good enough for now.

theiceman

ill have you know mine is pretty thick too ...

oh wait ..