EPS Motor Worn gear shaft removal

Y

yg54sg

Active member
Hi all , I did the hydraulic steering conversion a while back , just putting the motor back in so sport mode works has anyone removed the worm gear axle from the motor as I see no way of removing it , would like to remove it in the proper way ideally , appears to be no clips in front of the bearing etc

Failing that I’ll do a clarkson and dremel the shaft off but would rather not :rofl:
 
Searching the forum looks like someone has done a tear down of the motor and you can separate the control unit from the motor itself thanks for this https://z4-forum.com/forum/viewtopic.php?t=103782

Not much point in adding back a 10kg motor when I can create a custom bracket to mount the motors ecu/control unit and connect everything back up this should get the sport button back in operation for the throttle response curve.

This would also make it reversible rather than cutting/ removing shaft should for any reason I or someone wants to refit the motor … god knows why as the steering feel especially on the motorway a million times better no twitchy so don’t think I’ll ever be going back.
 
I also have a duff motor on my work bench which I plan to re-install (for sport mode) when hydraulic conversion has been completed. I plan to take the rear motor cover off (3 torx bolts)and thump the shaft to see if I can drive the front bearing and armature out, it must come out this way since that is the only way it can have been assembled in the first place. Also I have read that someone has just ground the front of the shaft off, not easy since it is a hardend steel shaft. Also, if the EPS ECU has failed, you still have to deal with the warning light (MOT failure item)
 
Ah so removing the rear cover then pulling the rear bearing off that floats against the back cover then pushing the shaft out the front is the way to go? Good idea I might try that. With regards to the warning light for MOT if you cut a very small square piece of black matt electrical tape and place using the end of a screwdriver fishing it down and over the light you cannot see the light or the tape at all except in direct sunlight, this has worked for quite a few years , I think on the z4 we are lucky as the lights sit between the 2 binnacles so not noticable ideally though I will code out the light with NCS Expert. 10 years since ive used that though as the last time was coding the light control module to accept facelift rear lights and I remember it being a pain in the ass!
 
Must admit after seeing your thread I did go straight to my garage and try. Have to admit the rear cover off was no problem, hitting the shaft even with a heavy hammer I could not budge the bearing. My guess is that you would probably need a hydraulic press against the shaft to shift the front bearing, still worth a try.
 
That motor is just pure quality, feels very expensive when you spin it and no play on the shaft at all, would be a shame to Dremel the end of it would prob go through about 5 discs doing it. This is why I wonder since you can separate the motor from the motors ECU just putting the ECU back, if that makes the car happy and activates sport mode again plus a weight saving of about 10KG ... ive put on weight since covid so every little helps plus you loose a couple of HP from going hydraulic :rofl:
 
I've just taken the black control box off the motor, connected it and duct taped it for the time being. All you need to do is remove the black putty over the terminals and take it apart.
 
Question for thecremeeeg
When you removed the ECU module from the motor, what did you do with the dangly tube that is attached by the 4-lead printed circuit strip to the module circuit board, did you leave it attached or un-solder and removed it ?? My guess is that this is some form of temp. sensing device to monitor the temp, of the motor body and my not be necessary.
 
Not that it matters, but the four-wire flex cable mentioned is likely from an optical encoder on the back of the motor which enables the electronics to know the position of the rotor. With the motor disconnected, the feedback from the motor is of course moot :).
 
I guess it must have been something like that, i will leave attached and box in for protection of the component. Not sure what good it will do re-connecting the ECU assembly (without the motor) since the EPS motor/ECU had an intermittent failure each time I started the car. I was able to make it work by turning the engine off and then on a few times and it would clear the fault. I guess this intermittent failure (if I re-connect) will always be there making the Sport Mode also intermittent (again, not that I actually bother to use Sport Mode).
 
Hi portculisz4,

If you can take a high resolution photo of the circuit board if you take your EPS unit out I can at least see if something leaps out as being off, like a broken bond wire.
 
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