[jimmyhsiung]

Today I installed and changed a failing DIFF w/original ratio 3.07 with ASD into a ratio 3.27 DIFF. It is a great success and nice swap, but.... when test drive, the ASD triangle warning light is on.

My tire size is all the same and I did move the original ABS teeth into the donor main shaft in the new 3.27 DIFF. There should be not speed difference, front and rear, in this setup. I guess.

Should I install the teeth ring in the proper and correct position relevant to the front wheel speed sensors? and how??!!

Is there any experienced expert who can direct me the possible way to solve this problem....

Any guidance and suggestions will really appreciated.

 

[winmutt]

If there was a ratio difference I would expect that ASD would just fire all the time. So more likely that its not picking up a signal? FSM have any electrical tests.

Today I installed and changed a failing DIFF w/original ratio 3.04 with ASD into a ratio 3.27 DIFF. It is a great success and nice swap, but.... when test drive, the ASD triangle warning light is on.

My tire size is all the same and I did move the original ABS teeth into the donor main shaft in the new 3.27 DIFF. There should be not speed difference, front and rear, in this setup. I guess.

Should I install the teeth ring in the proper and correct position relevant to the front wheel speed sensors? and how??!!

Is there any experienced expert who can direct me the possible way to solve this problem....

Any guidance and suggestions will really appreciated.

 

[jimmyhsiung]

1. Not "SYN" Speed, Front and Rear, is always the trigger of the ASD function.
That is why I remove the original ABS teeth (L6 sensor reading teeth) into the donor DIFF.
Speed sensors, L6 (in the DIFF), L6/1, and L6/2 (Front Wheel, Left and Right, speed sensors) should be reading the same rotation signals.

2. I will do a flash light codes test later to see if there is still something wrong.

 

[Maxbumpo]

Why did you swap tone wheels????

Please note that I'm far from an expert in ASD / ABS. I am assuming that the ABS computers in the two cars are interchangeable, and that the tone wheels on the front axle are also interchangeable. This would mean that the only difference would be the rear differential ratio and tone wheels.

It seems to me that the differential tone wheel was designed to provide a certain frequency at a certain speed. The speed of rotation of the tone wheel will be different between the two differentials, regardless of which tone wheel you installed. The 3.27 diff will be turning faster at 60 mph than the 3.07 diff, right? Therefore the original 3.27 tone wheel should have fewer teeth in order to keep the frequency consistent.

The ABS computer is comparing those frequencies (both front wheels against the rear axle) to decide if the rear axle has wheel spin. When it detects wheel spin, it tells the ASD computer, which activates the hydraulics to lock up the rear differential.

Do you also have a fault code / dash light for the ABS? I guess if you don't then you did the correct thing. In that case, reset the ASD computer by grounding pin 5 of the diagnostic plug (near battery) for about ten seconds, with engine running. That will clear all the error codes and should make the light go out.