PDA

View Full Version : can i install a servotronic box into a non servotronic car?



tim s
02-10-2007, 08:36 AM
Please Help A.S.A.P.....i have it partially apart already


thanks
tim s.

tim s
02-12-2007, 04:44 PM
they say it will work as if it was a non-servotronic box.
thanks
tim s.

George M
02-12-2007, 06:06 PM
Please Help A.S.A.P.....i have it partially apart already


thanks
tim s.
If you do, you will need a 12V feed down to the box with resistance to tune the effort. The default effort with servotronic steering boxes without electric power is higher then a convential BMW recirc. box. Servotronic boxes come with a dedicated ballast box (variable resistor) that connects to the diff speed sensor that changes resistance relative to road speed. The ballast boxes were known to fail and what I ended up doing was running about 10 ohms or so with 12V down to the steering box stepper valve on the bottom of the servotronic box. It worked pretty well.
My advice however is if you can find a non-servotronic box, do so. My thought is servotronic equipped BMW's was an early and ill conceived design effort.
HTH,
George

Kalevera
02-12-2007, 06:10 PM
It's a plug and play system on US cars. Find a control unit, find a box, plug it in.

Would advise getting matched box/servotronic brain, as the control units are apparently car specific (which makes sense based on what George is saying)

I have an extra servo unit from a 740, and probably a few from 750s. They're different than the 540 units, from what I remember, but it should at least get the assist to work.

632 Regal
02-12-2007, 06:45 PM
WOW we have George back with actual confusing technical information!
George did you get another Bimmer? I know you were looking a few months ago.


If you do, you will need a 12V feed down to the box with resistance to tune the effort. The default effort with servotronic steering boxes without electric power is higher then a convential BMW recirc. box. Servotronic boxes come with a dedicated ballast box (variable resistor) that connects to the diff speed sensor that changes resistance relative to road speed. The ballast boxes were known to fail and what I ended up doing was running about 10 ohms or so with 12V down to the steering box stepper valve on the bottom of the servotronic box. It worked pretty well.
My advice however is if you can find a non-servotronic box, do so. My thought is servotronic equipped BMW's was an early and ill conceived design effort.
HTH,
George

tnt525i
02-12-2007, 06:50 PM
ok at the risk of sounding dumb,,, whats servotronic?, is it an electrically powered steering system? does it use the hydraulic system? cause i just changed the steering box in my car, and wasnt aware there was a servotronic version.
sorry to hijack your thread tim s

George M
02-12-2007, 07:19 PM
WOW we have George back with actual confusing technical information!
George did you get another Bimmer? I know you were looking a few months ago.
Hi Jeff,
I just stopped in to say hello. You still in Michigan? How do you like this weather...lol?
My life has turned a bit. Yes, I got back into a BMW almost a year ago or so.
Found a creme puff of a 330Ci owned by a little old lady with only 6400 miles.
I kid you not. No winters...virtually no rain. Car has never been outside for a single night...lol. Here it is below. But honestly, I have gotten more interested in motorcycles and modding them a bit. I enjoy the speed and feeling of freedom on a bike. The danger is at times something to be concerned about however...lol. But I don't think I will even stop riding because its too much fun and I love motorcycles. Here are my two toys.
I see in your profile that you bought an 850. Wow! Quite a car. Any pics?
Cheers,
George
http://i26.photobucket.com/albums/c122/biker7/330CiDrSdResize.jpg
http://i26.photobucket.com/albums/c122/biker7/VegasatSpeed.jpg
http://i26.photobucket.com/albums/c122/biker7/VegasRHFront.jpg

Kalevera
02-12-2007, 07:22 PM
Vehicle speed sensitive power steering assist, versus engine speed sensitive (there's a -tronic name for the latter, don't recall it at the moment).

Theory is that you need more assist when the car is moving slowly.

tim s
02-13-2007, 12:23 AM
connect anything to it the valve position is set where it will have the same assist as a non-servotronic box.
he said that when they fail it is possible to have the valve stuck in an open or closed position which would cause it to steer really easy or really hard.
but i should not feel any difference with it disconnected.
tim s.

George M
02-13-2007, 06:37 AM
connect anything to it the valve position is set where it will have the same assist as a non-servotronic box.
he said that when they fail it is possible to have the valve stuck in an open or closed position which would cause it to steer really easy or really hard.
but i should not feel any difference with it disconnected.
tim s.
You can believe them if you want but if you run a servotronic box disconnected you will see that you obtained false information....the effort will be much higher then a std. recirc. box. Also, the servo (-tronic) on the box rarely fail...not even close to the weak link. The remotely located variable resistance box's that control power to the steering box based upon road speed fail with high frequency however. If you get one and don't supply power to it, low speed parking manevers will be all but unmanageable due to high effort. I know because I had one.
HTH,
George