I am writing this DIY as I couldn’t find anywhere that described how to DIY a front left axle replacement on a 2005 Porsche Cayenne Turbo, and the minimum quote I got was over $1000. This DIY will be more or less the same for both sides.
The reasons I am replacing my axle is that one of the CV boots was split when I bought the car, causing the whole corner to be coated in grease, and during some steering maneuvers I could hear grinding and moaning noises from the front left side.
I am happy to modify this DIY with feedback or other advice. This work is done at your own risk, I take no responsibility for you skinning your knuckles, damaging your car or anything else by using these instructions!
Total time taken to remove and reinstall the axle was about 3 hours and 2 beers, including taking pics and notes. The axle was a new GKN Loebro one that I got my local Porsche dealer to price match at $211
8mm (for undertrays)
10mm deep socket
32mm 12 point
Size 12 triple square socket (drive shaft removal)
T30 (?) to lock ball joints when loosening/tightening
T50 torx socket (to remove rotor)
Short and long handled ratchets
Large range Torque wrench
19mm box wrench / ring spanner
Ball joint splitters
Flat head screwdriver
Lots of shop towel / rags to clean up spillages
Consumables and parts
GKN Loebro complete new front axle 955-349-038-13 or 138-01187827 $211
(Autozone and Napa were offering remanufactured ones for $59 after core charge, but maybe these are lower quality.)
Caliper bolts (these are ‘use once, torque to yield’ type) N-906-854-03 $4.64 each
Axle nut (should be replaced if not with new axle already) W0133-1999019
Rotor retaining screw N-910-282-02-M1002
Apply parking brake firmly with the car on level ground.
Put the air suspension (if fitted to your car) into 'Service Mode' by pushing the Ride Height control forward for about 5-10 seconds. You should get a message about 'Regulation Switched off'.
Remove the center cap from the front wheel and using a long breaker bar, loosen the axle nut and front wheel lug nuts. Then jack up the car and put it securely on axle stands. Remove the front wheel. (I also put the wheel under the car in case the jack stands slip or break.)
For me to access the lower steering knuckle ball joint, I had to remove the brake caliper, rotor and dust shield (I intended to do this anyway, as there was so much grease in my left front brakes). You may not need to do this step if you use the alternate ball joint tool.
This is a straightforward job using 21mm socket, 13mm socket and a T50 torx. You may need to tap the rotor off with a mallet. I used a bungee to hang the caliper out of the way from the upper control arm. Make sure you spread open the pads a little in the caliper (without damaging them) to make it easier to reinstall later. If your brake pads are coated in grease like mine were, it’s safest to replace both left and right side pads with new pads.
Loosen the 3 ball joint nuts on the lower control arm, upper control arm and tie rod end until they overhang the end of the ball joint thread. (This is to reduce chance of pressure from the ball joint splitters damaging the ball joint thread.) Use the ball joint splitter to break the ***** joints taper grip on the hub upright. Now remove all 3 nuts - you may find that the ball joints spin when you try to remove the nuts. There is a torx fitting in the bottom of the ball joint bolt so you can prevent the spinning while you undo the nut with a box wrench. (Look up from beneath the ball joint.)
You may prefer to use this kind of tool, available cheaply from Harbor Freight.
Remove the long bolt that holds the middle of lower control arm to the mounting bracket in order to give enough wiggle room and clearance to pull the upright off the lower ball joint. You will now be able to pull the upright off the end of the axle.
Caution - As the hub upright has a number of brake hoses, electrical lines etc clipped to it, you need to either remove them or be very careful not to damage them when you hang the removed upright from the upper control arm.
Undo the 6x size 12 triple square bolts holding the inner end of the axle to the front diff. (I did not need to rotate the axle in order to remove all the bolts.) You can now slide the axle out and down through the rear gap between the lower control arm and mounting bracket. This will require a bit of jiggling the lower control arm around to create a gap but is not too tricky.
Clean up all of the area from grease and brake dust. Pay special attention to getting all the grease off the brake caliper, rotor and pads using lots of brake cleaner and degreaser. Check the condition of the brakes and pads. Now is a good time to replace them if needed. As a rule of thumb, if you drag your fingernail across the rotor and it catches, or there is a large lip at the edge, you should replace the rotor. You can get them resurfaced if they will be more than 32mm thick after the work.
If the pads are less than 3mm or greasy from a split CV boot, you should replace them.
Install the new axle back through the rear gap, make sure you put it in the right way around! (They are very different at each end, the splined shaft is the outer end.)
Feed the spline into the upright, then locate the inner end to position in the differential flange. Rotate the shaft to line up the holes, then put the 6 triple square bolts back in. Torque to 80 ft lb ? (I was unable to find the factory specs)
Left side faces the hub, right side to the diff
Reconnect the hub to the 3 ball joints and tighten the nuts. Torque to 65 ft/lb ? (I was unable to find the factory specs)
Replace the long bolt through the lower control arm and apply a little blue Loctite. Torque to 65 ft/lb ? (I was unable to find the factory specs)
Refit the dust shield to the hub, then the brake rotor. Do not get any grease on the on the freshly cleaned rotor. Torque the new rotor retaining bolt to ?? ft/lb. Optionally you can put anti-seize compound on the surface of the hub where it bolts to the wheel to prevent wheel from sticking to the rotor when next removed.
Bolt the caliper back onto the hub using new caliper bolts (*do not reuse old ones*). Torque the caliper bolts to 200 ft/lbs.
Refit the new axle nut until it doesn’t turn freely by hand ratchet.
Refit the wheel and lower the car to the ground.
Tighten the nut securing axle shaft to wheel hub, M24 X 1.5 and torque to 340 ft/lb.
Refit the wheel center cap.
Torque the wheel lug nuts to 118 ft/lb.
Tighten the nut securing axle shaft to wheel hub, M24 X 1.5 to Torques 340 ft/lb. If you don't have a torque wrench that goes this high, use a 24 inch breaker bar and put your whole weight on it. Assuming you are around 170lb, you just applied 340 ft/lb to the bolt ;-)
Refit the wheel center cap.
Torque the wheel lug nuts to 118 ft/lb.