Strut removal/replacement procedure question

I expect to begin this procedure in a few days. In Adrian Streather's 996 "Essential Companion" book, he refers to the Jim Williams method, where the top strut mount is left in place. But apparently the Factory Manual method involves removing the top strut mount. I am talking about the front struts here. Those of you who have done this, which method did you use? Also, is there a good DIY procedure somewhere? I couldn't find one on Renntech.org Thanks.

If you are going to leave the strut mount in the car, you have to use a spring compressor in the wheel well, which sucks and is dangerous. I took the whole thing out of the car. If you are truly a boss, you can unbolt the strut mount with the strut still assembled (so just undue all of the wires and brake lines and then the 3 nuts at the top) and then step on the control arm and push down on the strut to pass the whole strut under the wheel well and outboard to get it out of the car. Then you can take the whole assembly wherever you feel like to use a spring compressor. It worked for me.

You are going to need spring compressors whether you take the whole strut out of leave the top in. With a C4 there is a bearing at the top which should be cleaned and lubed so I recommend taking the whole strut out to do this. The challenge with a C4 is that the half shafts prevent the hub from dropping down far enough for the top of the strut to clear the fender. The manual says to remove the axle nut that holds the shaft to the wheel carrier and then press out the splined shaft. Two challenges with this, the torque spec on the nut is something like 350 ft lbs and the shaft is hard to get out of the wheel carrier. Here is how I did mine. I used a ball joint separator to separate the ball joints on the lower control arm and then slid the shafts out of the differential. They slide right out. Off course you have to remove the brake caliper and maybe the rotor too. Once this is done you can get the wheel carrier with the shaft attached low enough for the top of the strut to clear the fender. It is really a two man job, particularly putting the strut back in as you half to hold the strut up while the three nuts at the top are started onto the stud. The half shafts will slid back into the differential as part of this reinstall process. Did I say that it is also very helpful to remove the plastic shield under the front of the car so you can see the differential. And once you have the shafts into the differential you will need to tap them gently into the differential until they are fully seated with the journal of the half shaft into the seal in the differential. Probably ging to need to do an alignment after all this. This all sounds more complicated than it is. I am guessing that the first one took an hour or more, the second maybe 1/2 an hour.

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Wow...I sure hope it is not as complicated as it sounds! I appreciate the tip about the C4 half shafts issue. When the shaft is pulled out of the differential, does a bunch of oil come out? I mean, do I first need to drain the oil out of the front casing? BTW, I noticed in the "Essential Companion" that when installing a PSS9 kit on a C4 with PSM, the steering position sensor has to be re-calibrated using the Porsche System Tester. I am not installing a PSS9 kit, just replacing the struts with newer ones, but I suppose the issue with the steering position sensor would still apply? Well, I suppose if I have to take to to the dealer for a wheel alignment, they can do this as well. Thanks for the helpful advice, Doug.

The level of the fluid in the differential is such that it really does not drain when the shafts are out. But if you don't get them all the way back in you will be spraying fluid all over and will need to refill the differential. This is what happened to me. I had everything back together and was driving the car when I noticed some fluid dripping. And the Differential fluid is not easy to find, have to by it in bulk. My indy id the refill and the alignment and he was able to re-calibrate the steering angle sensor. I think the latest version of Durametric can also do this.

This was much easier for me on a C2!!! Wow.

Darn those half shafts

There's a good DIY on Renntech. I followed it and had no issues (C2). I too pulled the struts out fully assembled.

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OK, thanks. I had looked earlier on Renntech, but must have missed it. I will look for it again. I've changed struts on lots of cars, but never a 996. I always like to read the manual (if I have one) before starting a job I haven't done before.

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Dharn55: I wanted to double check this - there is nothing holding the half shaft into the differential other than the "inbound" pressure of the control arm on the botton of strut? So once the control arm and tie rod end are broken the half shaft will just slide out? Checking since this seems too good to be true! I tried removing the 32mm nut on the halfshaft and had no luck - my airtool would not move it at all - with a three foot pipe on a breaker bar all i did was bend the breaker bar - heat and chemicals did no good - so your technique is my last hope...

C2 is very easy, take the whole strut out. I put in all new Upper strut mounts, front & rear.

The torque on the axle nut at the wheel carrier is 300-400 ft. Lbs. as I remember. I don't have my manual handy to look it up. I just know that I could not get mine off. On my car the half shafts just pulled out of the center differential, not sire if that is supposed to be the case, but in all the discussions on doing this no one else has stated differently. Be careful to protect the splines on the differential and not get dirt and debris on the, use a plastic bag to wrap them. And when you reinsert them use a wood drift to tap them back in so that the shafts seat the seals. If not you will start loosing differential fluid.

My thanks to Dharn55 for his valuable information and this site for hosting in performing this job. I have just finished a complete front end rebuild on my 2002 C4S. I replaced the struts, upper strut mounts and bearings, tie rod ends, control arms and diagonal arms. If I had not known that it was possible to pull the half shafts out of the front differential this job would have been a LOT more difficult than it already was. My Pcar has about 87K miles and I knew it needed new struts as a minimum but my thought was if I was going in doing this work I might as well spend a few extra bucks and give it a major re-do as the labor involved , while not overly difficult , is very time consuming. The scariest part of this is pulling the axles out of the diff and reinstalling....hard to believe but the axles don't have any mechanical locking "thing" to keep them in. Just be sure that they seat back into the diff seals which is very easy to see from under the car. This is not as difficult as it seems, it just takes some time and patience.

I just put in a new set of coilovers in my C2. If you have a C2, there is no need for ball joint separators, or to loosen up control arm to lower the hub more. Use spring compressors and compress the $&@$ out of them and they will come out. In the rear you don't even have to remove the callipers. There's a couple of good write ups on both renntech and here. Make sure you put a thick layer of tape on the fenders where the struts will be coming out just so you dont scratch the paint.