RT final drive on GS now ABS fault

[Dewayne Harkov]

I came across a brand new 2009 final drive for 2009 RT and put it in my 2009 GSA which had a final drive failure. The RT drive had ABS cable already installed. I'm unable to use GSA cable as diameter of unit where it goes into rear drive is a larger diameter. I was able to connect RT cable under seat by removing blue plastic guide on plug then connected perfectly. I now have brake failure light on with ABS flashing and turn signals don't cancel. Speedometer sometimes doesn't work immediately but always will work after short ride and turning off and restarting then stays on permanently. Is this just an ABS reset issue? I have tried disconnecting battery but no joy. I am planning on going to dealer for check/reset as I have no GS-911. TIA

Edited April 17, 2020 by Dewayne Harkov
added pictures

[dirtrider]

10 minutes ago, Dewayne Harkov said:

I came across a brand new 2009 final drive for 2009 RT and put it in my 2009 GSA which had a final drive failure. The RT drive had ABS cable already installed. I'm unable to use GSA cable as diameter of unit where it goes into rear drive is a larger diameter. I was able to connect RT cable under seat by removing blue plastic guide on plug then connected perfectly. I now have brake failure light on with ABS flashing and turn signals don't cancel. Speedometer sometimes doesn't work immediately but always will work after short ride and turning off and restarting then stays on permanently. Is this just an ABS reset issue? I have tried disconnecting battery but no joy. I am planning on going to dealer for check/reset as I have no GS-911. TIA

 

 

Afternoon Dewayne 

 

Something not right there. 

 

The 2009 1200RT & the 2009 1200GS use the same rear wheel speed sensor.

 

Did you have the speed sensor  adapter centering ring when you tried to install your GS sensor on the RT final drive?

 

Your problem does sound like an incompatible rear speed sensor signal. 

 

Are you SURE that your replacement drive is the later Gen2 drive & not the earlier Gen1 (I-ABS) final drive?

 

If for sure you have the correct final drive generation then makes sure that your rear speed sensor is installed correctly (all the way seated) & that you have the centering ring installed correctly, or don't have 2 centering rings installed (if that is even possible).

 

 

 

 

[Dewayne Harkov]

I added pictures of RT sensor and bore in rear drive. The sensor is apx .100 smaller in diameter than other sensor. I wasn't aware of the Gen 1 and Gen 2. I have a 2008 GSA also and ABS sensor is identical as my 2009. I checked clearance of ABS to sensor rotor and is .015" so within spec. I hope I'm not screwed.

[Dewayne Harkov]

Here's pictures of 2009 GSA drive

[Dewayne Harkov]

Part number on GSA drive is K6/1 7712569-02. Part number on RT drive is K6/2 7712569-02. Does the number after the K6 the Gen number? If so can the dealer code it properly? I love the higher gearing and I only paid $400 for a brand new drive which I bought as time was running out and was on a ride so couldn't research much. Thanks for your help!!

[dirtrider]

32 minutes ago, Dewayne Harkov said:

Here's pictures of 2009 GSA drive

Afternoon Dewayne 

 

Please explain what picture shows what (be specific).

[dirtrider]

25 minutes ago, Dewayne Harkov said:

Part number on GSA drive is K6/1 7712569-02. Part number on RT drive is K6/2 7712569-02. Does the number after the K6 the Gen number? If so can the dealer code it properly? I love the higher gearing and I only paid $400 for a brand new drive which I bought as time was running out and was on a ride so couldn't research much. Thanks for your help!!

Afternoon Dewayne 

 

I don't have that info handy, when I get home later I will try to check my books to see if I can shed any light on the differences. 

[dirtrider]

48 minutes ago, Dewayne Harkov said:

I added pictures of RT sensor and bore in rear drive. The sensor is apx .100 smaller in diameter than other sensor. I wasn't aware of the Gen 1 and Gen 2. I have a 2008 GSA also and ABS sensor is identical as my 2009. I checked clearance of ABS to sensor rotor and is .015" so within spec. I hope I'm not screwed.

Afternoon Dewayne 

 

Remove the sensor on each drive, then clean one tooth on the rotor, then paint mark that rotor tooth, then count the number of teeth on each rotor. 

 

I doubt BMW can re-calibrate for a tooth difference but if the tooth count is the same then it shouldn't need any re-calibration.

 

Wheel speed input is based on tire size not gear ratio so if the rotor tooth count is the same then your speedo should read the same as with the other drive. 

 

 

[dirtrider]

Afternoon Dewayne 

 

Are there any part numbers or casting numbers on your speed sensors, is so post them up here.  

 

Are the wheel sensor pig tail connectors the same color?????

[Dewayne Harkov]

The second set of pictures are of 2009 GSA final drive sensor and bore. You can see the difference in bore diameters. There are no parts numbers on cables. The RT has a white connector which means Gen 1 from what I've read. GSA is black. Mike from Beemer Boneyard said that the 2 generations don't play well together but he doesn't know if slot count is different.. I'm guessing slot count will be different which is why the faults occur and self cancel doesn't work which I believe works off slot count. I'll try to count slots to compare. Thanks for all your help. You are the MAN!!

[dirtrider]

11 minutes ago, Dewayne Harkov said:

The second set of pictures are of 2009 GSA final drive sensor and bore. You can see the difference in bore diameters. There are no parts numbers on cables. The RT has a white connector which means Gen 1 from what I've read. GSA is black. Mike from Beemer Boneyard said that the 2 generations don't play well together but he doesn't know if slot count is different.. I'm guessing slot count will be different which is why the faults occur and self cancel doesn't work which I believe works off slot count. I'll try to count slots to compare. Thanks for all your help. You are the MAN!!

Afternoon Dewayne

 

Yes, it sounds like you are trying to mix different generations.  

 

[Dewayne Harkov]

So I guess my choices are to put in stock unit or ride without ABS. I'm still riding it.  I sure like the higher gear ratio for freeways. Sixth gear is like overdrive which is what I want. I may have to look for GEN 2 RT final drive.

[dirtrider]

23 minutes ago, Dewayne Harkov said:

So I guess my choices are to put in stock unit or ride without ABS. I'm still riding it.  I sure like the higher gear ratio for freeways. Sixth gear is like overdrive which is what I want. I may have to look for GEN 2 RT final drive.

 

Afternoon Dewayne

 

The short answer is to put the put the stock final drive back in. 

 

The long answer is to count the speed generating segments  on both final drive spools, then (IF) the same, maybe try to machine the side cover to accept the later speed sensor.

 

Or, see if the Gen 2 side cover will fit the new Gen 1 drive (will take a gear tooth contact pattern re-setup, or at least duplicate your current backlash). Lot of work to get the wheel mounting flange & bearing off of the final drives though.

 

If the spool segment count is different then you are probably out of luck unless you can research, then make, a pulse-per-mile  electronic matcher box of some sort.

 

 

[Dewayne Harkov]

I haven't taken time to count slots in RT drive yet but have a feeling they're different since sensor is just mag pickup. May be a project or just resell it. Thanks  again