Just a comment or two - the Servotronic rack and the non-Servotronic rack have different part numbers - meaning there is something different about them. There won't be any additional force on components on the suspension side of the steering rack (tie-rod ends for instance) - those forces remain the same. There will be more force going through the universal joints on the steering column. I think it's unknown what effect that might have on the longevity of those parts. It would be interesting to compare a PIG with a disabled Servotronic system to a PIG that came with a linear-force power steering system (aka - normal.) My WAG - the steering forces required will be less with the normal power steering than with the disabled Servotronic.

Does it make a difference? Who knows.. I see TomF has primarily 911 series Porsches of some type - which do have considerably heavier steering than a Cayenne. I've been learning to accept that with the Boxster too. I think it's partly what you're used to.

 

Great points Don. Heavier steering is certainly part and parcel to the earlier 911 experience, and that is what makes the steering feel such a pleasure at speed- you can actually feel connected to the road. My wife liked the 993 the best, probably because it was the lightest of the bunch and because the following cars were heavier and Cabs...

 

Our other Porsche is a 997 C4 Cab, and the steering is not really heavy with that car, although at slow speed in a parking lot it is a little more work than the Servo Cayenne.

 

I would say not just the U joint, but also the pinion attached to it inside the rack. This pinion engages teeth on the sliding rack, but it not designed to do more than sense where the driver wants the truck to go. It can, with force, move the rack side to side. Someone early in this post reported that slow or no speed turning forces were much heavier with the fuse pulled.

 

I run the servotronic in my CTT because all I care about is accuracy and force is secondary. I'm fine with the steering as is. You could have a valid point. Servotronic is simply a solenoid and valve on the rack to vary assist fluid pressure.

 

I sometimes get a slight wander on the highway at high speed in mine even though the alignment is perfect. I'm wondering if the Servotronic is overboosting subtle steering inputs that I am then consciously correcting for. I'm going to try this to see what it does. Tom, since we both have 09 Turbo Ss, what fuse # is it and in the left or right dash bank?

Thanks.

 

You asked the same question of me back in 2017 and somehow I never remembered to respond! I'll have to check later for you. It is definitely on the driver's side.

 

I also did a CHF202 hydro fluid flush yesterday to see if it would get rid of some small displacement high frequency flutter I would get in the steering wheel and front wheels while idling around the grocery store parking spaces. Especially when turning the wheel with the brakes on.

It did take away about 75% of that type of flutter (we have 127K miles). Still a very small amount left.

BONUS-high speed down the road stability is way better than before. Truck used to have some jitters, especially down two lane wavy and narrow blacktops. Harder to drive than the 997 in that area. Now, stable as a rock, feels like a new front end. Two fingers on the wheel (no oncoming) versus two hands in these wavy twisties.

I found this fuse layout for 2003-2010.

http://knigaproavto.ru/shemy/en/pors...x-diagram.html

 

Drivers side behind panel - fuse 48 (5 amp) which is two slots from last on bottom row - last fuse bottom row closest to driver seat is #50

All from memory of doing this a couple days ago so check the panel guide

HTHelps

G

 

So, I think I may be committed to this mod. I snapped the connector off the servotronic solenoid while dropping the front diff.

before I put this all back together, anyone know if this version of the mod is likely to throw codes?

 

FYI, your connector body looked destroyed but not the pins. I've put pins into new connector bodies several times when I've accidentally cracked them during removal. It's pretty easy so I don't think you're stuck here if you want to reconnect it.

 

Came across this thread because my ‘08 CTT in recent months developed a hesitation in steering at lower speeds (50-70 kph) and it’s extremely vague at highway speeds (130 kph+). I’ve had some suspension issues in the past year as well (level sensors, compressor) and somewhat irrationally blamed the PDCC. My mechanic said he thinks it needs lateral sensor calibration, which may be true, but I’m tempted to pull the fuse anyway given the descriptions of the effect.

However on a list of the fuses, I notice it’s fuse #49 — and that’s not just servotronic, but also the swaybars — so would that also disconnect the PDCC?

 

If you want to try it, just pull the plug off the servotronic solenoid.

Or send me yours and I’ll send you mine 😜

 

Interesting thought. I will have to check and see if the fuses are the same as I thought they were seperate.

Update- Thank you for posting this question- after examining the tandem pump, I suspect you may be correct... with the caveat that the PDCC system may be a "dumb" mechanical hydraulic system without any substantive electrical control... but I am not sure.

Anyone else want to chime in here? Where is Don when we need him?!

 

I think PDCC almost has to use the level sensors as a signal. How else might it know to apply torque when there is a difference (roll), not just when they (both) move up and down (bounce/jounce)? Also, when we apply a lift and use the adjustable sway bar links, it seems to automatically work okay without being precise about the length of the sway link.

you can also just unplug the servotronic wire from the servotronic device on the steering rack. The wire runs through the driver side wheel well, and can be traced to the rack. I managed to rip it off during a subframe drop, so I love this (irreversible for me) mod.