Hi everyone,

I'm in the process of installing Bilstein PSS10 coil overs on my 964 and I think I made a serious error and stripped out the female Allen key on the main bolt (piston rod?). I read the instructions that accompanied the suspension but a lot of it is in German. I noted the 34 ft.lbs of torque mentioned in the booklet for M12 (19mm nut) and attempted to torque it down using an Allen key attached to my torque wrench and the bit slipped prior to reaching 34 ft.lbs.

I noted afterwards (totally my mistake) that the manual states that you're not to torque down the nut until the shock is installed, but I have two questions... how would one access that nut to torque it once its installed, the space surrounding the rear shock mount is very tight? and would this have prevented the stripping, seems unlikely but I don't know. The ride height rings (springs plates) were left at the position they were shipped at, set at about halfway up the adjustable threads.

The nut on the main bolt (piston rod?) is currently threaded down exposing about 1/2" of threads above the nut and must be extremely close to 34 ft.lbs of torque.

Does anyone have a step by step instructions on how to install these as I don't feel like the accompanying documents are sufficient? I fear torquing down the remaining three shocks and I'm wondering about repairing the rod I've damaged. Any and all experience with these coil overs would be greatly appreciated...

I also wanted to include the torque chart to make sure I've read it correctly:

Thread: M8: 10 ft.lbs
Thread: M10: 19 ft.lbs
Thread: M12: 34 ft.lbs
Thread: M14: 54 ft.lbs

I looked up M10 and it equates to the 19mm piston rod nut that came with the Bilstein coil overs... but the instruction says "M10 thread" is that different than the nut?


Thanks

 

Confused? The shock you have damaged, you referring to the front or rear? Pictures would help.

 

Photo would be a good start.

 

Sorry, I'm just learning how these forums work, I've attempted to upload two images, one of the stripped piston rod and another of the shock as it sits.
The coilover is for the rear of the car.

Thanks again for helping me out with this, as I mentioned I believe the piston rod nut is darn close to 34 ft.lbs as it was really tight when the bit slipped and stripped the bolt.

 

Try some carbon paste on the allen key. Carbon paste has small particles embedded into the paste. Turn the nut not the allen key. Use a crow foot or a slotted socket. A picture below using it on the front shock.

 

Thanks, Spokes, I will try and find a slotted socket with a wide opening like the one you've shown above, what brand is it? The majority of what I see online only have a narrow opening which I suspect won't work as they won't allow you to hold the Allen key in place and turn the nut.

Would you be able to provide some clarity with regards to the installation:
1. Did you complete the final tightening of the upper nut after the car was on the ground (front and rear?)
2. Were you able to achieve the torque ratings as outlined below (34 for the rear and 83 for the front)?
3. Am I interrupting the chart below correctly?


Am I correct in my understanding a M12 thread being a 19mm nut and therefore requiring 34 ft.lbs of torque?

The issue I see is the nuts on the front coil overs are 22mm which I believe would be M16 with a torque of 83 ft.lbs which seems next to impossible to achieve?

Would someone be able to confirm my conversion from M to nut size is correct and if these are the torque numbers they used?
Thanks for your help Spokes.

Josh

 

This link is a great DIY guide. http://www.964uk.com/Documents/Bilst...ion.pdf#page16

IIRC the rear you set the torque prior to installing. Installation is reverse of removal.

I used the factory torque values. My bilsteins didn't come with a torque sheet. Also just set the collars in the same position as the old shocks. You will have to set the height from there by adjusting the collars against the measurement points.

The slotted socket is mainly used for O2 sensors. Just search "slotted socket" lots of variations.

 

Thanks again for responding and the link it certainly provides step by step instructions on the process.

My main concern is the torque specs, and if I'm interrupting them correctly, would someone be able to confirm my thoughts on the post above...

Where did you get the factory torque values?

I found this socket, but will it work? The slot is narrow, and I don't think it will allow you to turn the socket while holding the Allen key in place?

 

All the manuals can be downloaded from here http://early911nzdownloads.yolasite....op-manuals.php Volume 4 Chassis Manual has all details.

 

Excellent, thanks I'll download those.

Josh

 

I have done a few sets. What has worked for me is for the fronts, tighten them as much as you can then transfer them to the car and torque them like the pics shared earlier.

For the rears, you will need a big vise and ideally if you have a helper to secure the Allen key while your torque the top but works best.

I used a make shift holder for the Allen key using a socket and a steel tube to hold the Allen key in place. Pic attached.

Lastly, various options to torque the top nut, an offset box wrench socket, an o2 sensor socket (works for the front but), getting a cheapo spark plug socket and cutting a slot, or buying the specialized split socket from Hazet or Schwaben.

Lastly, I believe the front is a m14 and rear
is m12. You also have nylocs which serve as a locking mechanism so get them as tight as you can. 80+ ft lbs is too high. I have 43 ft lb and 59 ft lb rear and front respectively.

Here is a diy guide for a 993. Should give you an idea with pics.

https://drive.google.com/file/d/1TfJ...w?usp=drivesdk

 

Thanks samurai_k for taking the time to respond.
Were your previous installations with Bilstein products?

Rear Coil-overs:
The manuals Spokes provided mirror the torque numbers you stated 43 ft.lbs in the rear and 59 ft.lbs in the front. I guess my immediate concern is I don't think I'll be able to torque the rears to 43 ft.lbs, they're probably very close but I stripped out the allenkey while torquing them off the car. I may try and create a 19mm slotted socket and further tighten it down but what are my options if I can't? The Bilstein manual states 34 ft.lbs as opposed to the 43 ft.lbs in the Porsche manual... I'm probably very close to the 34 ft.lbs, should I just install them?

Front Coil-overs:
I was able to locate a 22mm Schwaben open-sided socket at a local shop (going to pick it up tomorrow) so I'm hoping that will resolve the front Coilover installation. I'm a little nervous about torquing these down, but I feel turning the nut vs the allenkey will hopefully prevent any issues.

Thanks again to everyone.

 

 

Thanks for the image Ralph, were you able to torque your front coils to 59 ft.lbs without issue using that?

 

The problem is the allen in the shaft, I got close.