flickroll

First I hope this thread does not migrate to a debate of centerlock vs 5 lug wheels....

Have a question to those that do centerlock wheel removal and replacement by themselves. I recently removed and replaced a centerlock wheel on my GTS. The procedure is straightforward and the process went very smoothly. I modified an Irwin bar type wood clamp to apply the brakes during the work, so that was pretty easy. However when applying torque to the wheel nut the steering wheel turns. Eventually I had to get my wife to hold the steering wheel straight while I was torquing the nut. I would like to be able to do the entire job without assistance. So the question is, is there a practical way to hold the steering wheel, or does that issue mean that I will always need a helper? Thanks

Dennis C

I have my wife hold the wheel too.

Porsche_nuts

Really kind of hard to do it by yourself without the wheel turning. The only thing I can think of to do is to not lift the front end all the way - leave the front wheel touching the ground enough so that it will not move as you torque the center nut. Once the nut is broken, lift the car and finish the removal process. Give that a shot and see if it works. Unfortunately, you won't be able to use this method when putting the wheel back on and re-torquing it.

Gordon Shumway

Does the steering wheel move with the car on the ground? You surely don't have to apply the final torque with the car on jackstands, do you? I've never torqued a wheel at 400+ ft/lbs, but I've never fully torqued a wheel in the air with regular lugs.

Porsche_nuts

You are supposed to torque it with the wheels off the ground.

Gordon Shumway

Is that just center locks, and any idea what the rationale is? I mean really, how much is that wheel moving when you apply the final 100-150 ft/lbs of torque?

flickroll

It is because of the conical shape of the nut locking system: the shape of the portion of the wheel nut that makes contact with the wheel itself is conical. The nut has a male ‘cone’ and the wheel is female conical. So if there is any load on the wheel when tightening the nut the wheel won’t be perfectly aligned when the nut is tightened. The instructions for tightening are very specific that the wheel must be off the ground. When removing the nut you can jack the car so the wheel is touching the ground just enough so it won’t spin when you use the breaker bar, just as Porsche-nuts said. But going back on the wheel MUST be off the ground. So when you apply 444 ft-lbs of torque to the wheel with the torque wrench, the wheels turn and it is difficult if not impossible to apply the correct torque.

Gordon Shumway

OK, I did not realize it was conical, and that makes sense. Not sure I entirely buy it when we are likely talking about a 1/4 turn or so for that final torque, but it does makes sense.

PTGFAR

Are you doing it with the opposite side tire on the ground?

flickroll

Yes, why? From the owners manual:

Preparing the vehicle

1. Select PDK selector lever position P.
2. Apply the parking brake.
3. Remove the driver’s key.
   Vehicles with Porsche Entry & Drive: Remove control unit.
4. Secure the vehicle to prevent it from rolling away, e.g. by means of wedges under the wheels on the opposite side.
5. Lift the vehicle only at the specified jacking points.

Please see chapter "Raising the vehicle using a jack, floor jack or lifting platform".

Raise the vehicle until the wheel lifts off the ground.

Ensure that the vehicle is not standing on the wheel to be secured during fitting.

flickroll

Actually rereading the owners manual gave me an idea on my solo centerlock question. Chocks the length of which are the same or greater than the tire width, and with the proper angle cut on the chocks and positioned tightly fore and aft against the opposite wheel, might prevent the wheels from moving left or right. Might give that a try next time. Worst case is it won’t work and I’ll have to get my wife again and then take her to dinner.

evilfij

Ratchet strap or rope on the wheel maybe?

PTGFAR

I was thinking the wheel on the ground would prevent the wheel from turning during tightening. I also wonder if there is a danger of the wheel on the ground causing the car to fall off the jack or jack stand when it tries to turn.

Porsche_nuts

Give it a shot.

I actually jammed a brick against the lifted wheel - on the same side - when tightening. Did not work - wheel moved. The brick was not the same width or greater than the tire width though.

flickroll

Oh, OK, I thought maybe you were going somewhere else with your question, sorry. I saw a thread on 6speed in which someone said if you don’t raise the opposite wheel as well there’s a danger the wheel you are working on could later fall off

I don’t think there any danger of the car coming off the jack. The car seems very stable even when using the torque wrench.