Cardan shaft w/o a lift

iamtheari · 09-23-2013, 07:09 PM

How much space do you need to work underneath the 955 Cayenne Turbo to replace the cardan shaft? I can probably get a lot of clearance on jack stands but I'm wondering if that will leave me banging my elbows and forehead on things a lot. This job has been done in the past on my car, according to the PO, but some rumbling when accelerating hard through 45mph (and occasionally at other times/speeds/circumstances) tells me that it's time to do it again.

mtnrat · 09-23-2013, 10:20 PM

I put mine at the highest setting and then drive up on some ramps made with 3- 2x6". Lots of room.

mark4ton · 09-23-2013, 10:59 PM

did mine in standard height, jacked the back up enough to get the rear wheels off the ground. easy breezy.

iamtheari · 09-24-2013, 06:51 AM

It seems to me that having the rear wheels off the ground would be helpful, allowing you to turn them and thereby rotate the shaft to get at all the bolts. Or is there enough space to get a wrench at each of them without rotating the shaft itself?

mark4ton · 09-24-2013, 06:03 PM

exactly the reason I got the wheels up. make sure its in neutral and chocked.

Mike80911 · Mike80911's Garage

I just did mine with jack stands. I used a 4x4 on top of the jack to get some extra space. Really very easy to do when laying on your back. An impact gun is really a big help. Mine went twice in a couple of years so I used the "lifetime replacement bearing" this time. You only need to drop the front of the shaft to replace the dampner. The whole jib took about an hour.

iamtheari · 09-27-2013, 08:44 AM

Thanks everyone. Is there a relatively quick and easy way to verify that the cardan shaft is my problem? I will be changing the oil in the near future and would like to verify that this needs to be done before splurging on the parts.

Mike80911 · Mike80911's Garage

When you slide under the car you can see the bearing try to move the shaft back and forth there should be very little movement in the shaft. Make sure the shaft is cold when you do this or it will hurt a lot.

iamtheari · 09-27-2013, 02:28 PM

Back and forth as in longitudinal to the shaft, forward and backward with respect to the car? Or side-to-side? I'm assuming very little movement means it's good and noticeable movement means it's time to replace.

Given the shuddering between 35mph and 45mph when accelerating anything more than soccer mom pace, I think I'm going to find a shaft in need of replacement. But I really appreciate the help confirming that before I tear it apart.

Mike80911 · Mike80911's Garage

Side to side meaning right to left and up and down should have very little movement. You should not be able to move it front to back at all.

Marko911/944 · Marko911/944's Garage

I replaced mine on Friday with a complete unit exchanged from Coloradodriveshaft.com (recommended on another forum). At first I thought I would just replace the center bearing myself, but upon further inspection of the 2 drive shafts I had, a professional rebuilt replacement was needed. Just jack up the rear as far as possible, have the 18mm socket and 18mm open end, a small prybar and the triple square socket for the diff end and you are good to go. There is great info avail at the above web site, especially about doing this without dropping the exhaust.

iamtheari · 09-28-2013, 09:25 PM

Thanks for the information, even if your pictures seem like a passive-aggressive implication that "without removing the exhaust" means "with removing the entire drivetrain."

iamtheari · 09-28-2013, 11:41 PM

Good tip on ColoradoDriveShaft.com as they look like a good source for the shaft. Are any other parts needed beyond what they supply?

Marko911/944 · Marko911/944's Garage

I've been told that Porsche recommends replacing the hardware at both ends of the drive shaft, but I just used a bit of threadlock on each bolt. As a side note: The best mechanic I know once told me that a can of silicone based spray lubricant can be a good friend. Everytime you are under your vehicle spray all the rubber bellows on cv joints and drive shaft bearings to extend their life. Since I started doing this on my small fleet I've never had a failure (my 2 955's had failure when I bought them). On my project yesterday- rear subframe details and brakes. I can't wait to test drive my low $ ride!

iamtheari · 11-03-2013, 06:09 PM

I just attempted the job...and failed. I got the six bolts off the rear, the six bolts off the front, and the bearing support removed. What I couldn't do, though, was remove the actual shaft from either end. I was able to pry the protective cover of the rear loose but the actual flange didn't move a millimeter no matter what I tried. I also tried to pry the front off the transfer case, but it seems like the flex disc, transfer case flange, and drive shaft flange have welded themselves together.

Any tips I can try the next time I attempt to install my shiny new driveshaft? Thanks.

Marko911/944 · Marko911/944's Garage

Mine was stuck too. Both ends of the shaft are slightly flanged (take a look at your new one and you'll see how much you need to move it) and can broken loose with a few 'solid' taps from a hammer. I held my driveshaft up with wire to keep it from falling to the ground.

iamtheari · 11-04-2013, 08:25 AM

Thanks for the response. It seems almost impossible to get a hammer in there to tap anything but the shaft ahead of the rear joint. I did get a wood block against the rear joint and pounded it as hard as I could underneath the car but nothing moved. I also got out a chisel and put it against the joint where it should be able to split (after prying the protective cover out of the way), but had no luck there, either. I've heard of people using an air chisel and I'm getting tempted by that option.

Where exactly did you tap the rear?