Any differences in xdrive power steering?

[Aaron]

Hello all! 2011 335xi automatic. I blew the motor and thus swapped over a known good N55. But the good motor was from a RWD car.

Upon first start and driving, the steering is really tight. PS is quiet and full, but the steering is definitely way too tight.

Does the AWD motor require a specific pump/pully? My Dad suggested because of the AWD it might, and I can't remember if I used the RWD pump or not.

Thanks all!

 

[Aaron]

Trying to cross-reference part numbers from realoem right now. Still need to check if one of the cars had active steering, but I don't believe either one did.

RealOEM is showing both xi and I have the same pump and pulley, but the pumps differ for active steering cars.

I've confirmed neither car had active steering, so they're both the same.

On a side note, I also did not use the right PS fluid. It calls for CHF11, I used auto parts store generic PS fluid. So I'll swap that over too.

 

[Aaron]

Ok, pulled apart the entire front end, isolated the problem to the steering rack. Even with the wheels disconnected from the steering the rack is still significantly more difficult to move than it should be.

I also changed the fluid, no difference.

I'm going to swap racks here in the next couple weeks. No idea what the problem is with it, it's only got 86k on it .

 

[doublespaces]

So you swapped only the pump and not the rack? Because there is a solenoid/restrictor that dictates how easily the fluid flows through there. On the M3 that solenoid has a plug you can connect to in order to adjust it.

If you have active steering it would be pretty obvious, there are a couple plugs that go onto it. A normal rack does not have any wires going to it.

 

[Aaron]

So you swapped only the pump and not the rack? Because there is a solenoid/restrictor that dictates how easily the fluid flows through there. On the M3 that solenoid has a plug you can connect to in order to adjust it.

Correct. I kept the AWD rack in the AWD car, but kept the RWD pump on the RWD engine when I swapped it in.

I have difficulty thinking that the rack is just out of adjustment. I mean, how would that even happen? Especially that it's so far that it's obvious the minute you touch the wheel that something is wrong.

In any case, how can I adjust this solenoid on a 335 rack? Does it still have a plug? I'd much rather adjust it then swap racks (Which is my next option).

No AS on either car.

 

[doublespaces]

No idea. I just know servotronic does some magic and it has to do with the valve thingy on the side. The pump might just be bad. If there was air, you'd get a shit ton of groaning most likely.

 

[Itsbrokeagain]

Did you check the telescoping rod/steering u-joints for range of motion? There was a bulletin out back in the day for stiff u-joints and would cause the steering wheel to be really hard to turn. Usually the dealer replaced the piece..

 

[Aaron]

Here's the thing I hate about forums.

Ok, pulled apart the entire front end, isolated the problem to the steering rack.