Steering rack upgrade from PR-1N2 to PR-1N4

[Jay-Jay]

I am not going to replace the steering pump, but the steering rack.
And I can't connect the G250 sensor's wiring to the new PR-1N4 steering rack (6R1 423 055 M), because it doesn't have the G250 sensor's housing at all.

[RUM4MO]

Ah, sorry I had kind of forgotten about that even although I knew why you were making this change!

[Jay-Jay]

Today I've finally replaced my steering rack with the PR-1N4 one.
These are a few pictures of the old PR-1N2 steering rack I removed and of the front subframe:



This is the PR-1N4 rack installed on the subframe:


As I already said in my first post, the steering ratio is shorter. Now I only need about 1 turn and a half to reach the limit stop of the steering rack from "0" position, but at the same time the steering angle on the front wheels is even wider than with PR-1N2 steering rack.
This is a short video that shows that:
http://youtube.com/shorts/wwqgol1zYKY?s ... lKaSqtTshO

While reinstalling everything together, I also correctly alligned the front subframe with the proper pins.
Now my car desperately needs a wheel allignment, since my steering wheel points to the left and I feel like the front left wheel is a bit turned on the left while I go straight.
BTW, the steering feels amazing. It's a bit heavier, but much more reactive and solid, especially at high speed.
Also some annoying vibrations I used to feel with the old steering rack at about 120-130km/h (most probably due to the wear inside the steering rack), now have completely gone and the steering feels very firm and precise (despite the front wheels still not properly alligned).
I'd definetely reccomend this upgrade to everybody who needs to replace the steering rack.

For those who snooped around on ETKA and noticed that the tie rods for PR-1N2 rack have different part numbers than those for PR-1N4 rack, I installed mines on the new rack without any compatibility issues. As a confirmation, if you read on MEYLE's online catalogue, they have recently unified all the tie rods part numbers under the same numbers indicated as compatible for both PR-1N2 and PR-1N4 racks.
Another curious fact: despite being 1lt (more precisely 0,9lt) the total quantity of steering oil, I only drained and refilled about 500ml.

[ciclo]

Good job! thanks for the advice and info.

What happened to the wiring that was supposed to go to G250? Did it make any sense for it to be factory installed on your 6R?

---
Fun story that is not a comic:
A long time ago, at a VW workshop, they removed the consoles attached to the carrier assembly - subframe - from one of my old cars to replace the cracked rubber bushings. This 'task', not stated in the repair manual, was done this way to change the rubber bushings more easily than with proper tools, because it is not necessary to remove the consoles or subframe to do this job.

When the parts were reinstalled, the mechanics did not align the subframe correctly and the wheels squealed in all corners no matter how much the steering wheel was turned or the speed of the vehicle. It was a real disaster because it was then very difficult to realign the subframe and the entire steering assembly.

[Jay-Jay]

Thank you, Ciclo!

I simply cutted and removed the G250 wiring and I left the connector plugged on the pump. Then I used a cutted rubber glove's finger tightened with a little plastic tie to seal the few cms of exposed cutted wiring and protect it from any oxydation and dirt.
Apparently the G250 sensor was there just for no reason, since my ABS Unit is factory coded to read the steering angle from G85 sensor.

Regarding the front subframe allignment, I've always been told that if not done properly, it is still possible to compensate with a wheel allignment on the steering rack.
In my case, I used the proper centering pins, as indicated on ElsaWin. When doing this job, the tie rods, the whishbones and the gearbox mount have to be disconnected, otherwise they apply a little tension to the subframe, not allowing an easy centering.
In my case, this job has never been done and I suspect my front subframe wasn't properly centered from factory or that it could have moved with time and usage of 13 years.
In the end, I think you need less or the same time to do a job correctly than incorrectly.

[amer6R]

Cool mod, I'd recommend to get the balking connector on the power steering pump

[Danypolo5]

I would take advantage of the post to ask if it is possible to mount the same rack (6r1423055p) on a 9n3 polo without esp (1.4 tdi sportline so sport chassis)

Interesting question. According to the diagrams for POLO 9N3 it is the same as for 6R, that is, if it has the G250 sensor connected (for 9N3 with ABS without ESP) it does not have the G85 sensor installed (for 9N3 with ESP).

We installed a G85 sensor in a 6R with an ABS brake unit - without ESP - and at least it worked for the static cornering lights data.
viewtopic.php?p=520550#p520550

So you can investigate yourself by installing the G85 sensor in your 9N3 and disconnecting the G250 sensor to find out to what extent it is possible to do what you want to do.

--- More info ---

6R (diagram that I posted in a recent thread).


My J500, 1.2 TSI (ESP).

The connector behind the drain tube is a simple connector/plug without wires. It corresponds to the wires that would go to the G250, but my 6R is with ESP (G85) so there are no wires there and not in the steering rack either.

9N3


T41 (6R... 9N3*)

in the meantime I'm proceeding like buddy jay but I need a few more pieces because I'm also doing a subframe swap; do you recommend combining the 2 models or is it better to create a specific post in the 9n3 section?

[iichel]

I'm okay with using this topic, the info is relevant to both 6R/6C and 9N/3 cars since the front axle is very similar. Just note you're doing it on a 9N3 in your post please. Looking forward to your contributions.

[Danypolo5]

so in the meantime I received the subframe from a 2015 Fabia, plus all new Meyle reinforced arms and heads



now I think I have also found the g85 to use derived from a 9n3; I'm waiting for the pin photos to see if it's in good condition (in the meantime can you confirm that it's right? I could also use one of the 6r but I've already modified my golf 7 steering wheel connector to fit on the 9n3)



if I get it I will start retrofit tests; while the search for the steering box 6r1423055p continues

[Jay-Jay]

Hi guys,
I revive this topic, since I have a weird problem.
It all started immediately after I replaced the steering rack.
The same night after the replacement, I took the car for a test on the roads I know well and right in the middle of taking a specific turn that I always use for testing the car, suddenly the ESP kicked-in very abruptly.
At first I didn't give it importance, since I had old tyres and I thought they were the cause.
But now, after having replaced tyres (with Michelin Pilot Sport 5), wishbone bushings and struts (with upper bearing and top mount), the problem persists on the same turn and other similars ones.
I am concerned it has to do with the steering rack replacement. If not a mechanical problem, maybe an electronical problem related to the lack of G250 sensor?
I completely checked all the suspension components. The front axle of the car doesn't show any noticable play. Everything is tight and solid.
To better explain the problem: the ESP kicks-in abruptly when I quickly take specific turns and I have to turn the steering equal to or more than 45°.
The ESP activates on the front caliper external to the direction of the turn. So, for example: if I turn right, it activates the front left caliper and viceversa.
And when it does, it is scary, because it makes an horrible sound and the car suddenly stops accelerating and it abruptly understeers.
While driving I had the impression the problem is more present when turning on the right than on the left, but I'm not 100% sure about this, since it just might be due to the kind of roads on which I've been able to test the car.
I did multiple times the basic settings for G85, G200 and G202 sensors, but the problem is still there.
Recently I replaced the entire rear beam axle with the stiffer GTI one and I installed installed rear axle poly bushes.
This modification increased the oversteering tendency of the car, but at the same time increased the problem explained above.
Now the ESP kick-in more frequently as soon as I quickly take a turn.
What do you think might be the cause of the problem?
Could it be that my ABS unit is coded to use G250 sensor when specific conditions are met?
Maybe I need to modify the ABS unit coding?
No errors are stored in any units.
I'm really stuck.
Any suggestion on how to investigate are much appreciated.

[iichel]

hey jay jay, do you have any error codes? is your alignment ok? did you align with steering angle @ zero?

[Jay-Jay]

Yes. Alignment done with steering at 0° and there are no error codes in Engine, ABS and Steering units.
After the latest works (struts and rear axle beam) I haven't done the alignment again, but at this point I am not sure if it might be an alignment issue, because even when I did it immediately after having replaced the steering rack, all the values where almost perfect but the ESP problem was still there...

Another detail that might help: with the car still, if I turn the steering all the way to the limit stop (left or right doesn't matter) and the road surface is not perfectly smooth (like the one of a garage) I feel a weird resistance almost at the end before reaching the limit stop.
With my hands on the steering it feels like one or both front tyres hit a bit against something inside the wheel arch and they need some more force to go to the end of the steering limit stop.
If I do the same on a perfectly smooth surface, there is absolutely no resistance till limit stop.
I never had this with the old PR-1N2 steering rack.
What do you think?

[iichel]

perhaps you can try to change the last digit of your 0x44 coding from 0 to 1

[Jay-Jay]

I already did that.
Now I am using the coding 11221, which is the same coding found from factory on Polo 6R GTI and R WRC and Audi A1 with PR-1N4 steering rack.
Apart from the problem explained above, the steering feels amazing: precise, solid, direct and reactive.
Yesterday night I tried to take the same problematic turns but with ASR disabled. There is a bit of wheels slipping, but the ESP kicks-in a lot less aggressively. Before, with PR-1N2 steering rack, I never had to disable ASR to take those turns.
I can't believe this has to do with the different steering ratio. There must be something else I am not considering...
When I did the steering rack replacement, I aligned the front subframe with the proper VW centering pins and then I removed one by one with the subframe's bolts. Those bolts were not new.
Could it be that they are a bit stretched and the front subframe is slightly moving while under stressfull conditions (like turns)?
Maybe I need to replaced them with new one and torque them as VW says?

[iichel]

I can hardly believe the bolts are the issue. Could you post a scan of your abs? I'll look into some more coding stuff