Welded diff + ABS ?

[tossaxe]

Hello,

I've aquired s13 open diff internals, got them welded and put in my s14 zenki sr20det. Now ofcourse my ABS light is on and not working too well.
Is there a way to still make the ABS work?
Or short some wires on the diff housing so that ABS would still work at least on the front?

[oni jake]

In short answer. No, you cannot make ABS work with a welded diff. The entire perimeters of the ABS program needs to be reworked to accommodate 2 wheels locked. No company or person, that I know of, can do that.

Disconnect fuse to ABS, pull the gauge cluster bulb, and work on taking all of that crap out.

[tossaxe]

What I needed to hear. Thanks

[jr_ss]

Originally Posted by oni jake

In short answer. No, you cannot make ABS work with a welded diff. The entire perimeters of the ABS program needs to be reworked to accommodate 2 wheels locked. No company or person, that I know of, can do that.

Disconnect fuse to ABS, pull the gauge cluster bulb, and work on taking all of that crap out.

S-chassis' only have one speed sensor for the rear, located on the snout of the differential, so he shouldn't have an issue with it...

[oni jake]

Originally Posted by jr_ss

S-chassis' only have one speed sensor for the rear, located on the snout of the differential, so he shouldn't have an issue with it...

Dude, post something worth a damn instead of getting your post count up. Contradicting what I said with no logical reasoning doesn't help anyone. If by your logic there isn't a problem with running a welded diff on a ABS S-Chassis, then post possible reasons why his ABS malfunctioning light is on.

S-Chassis have 3 wheel speed sensors. Two in the front, measuring directly off the hub, and one in the rear measured off of the differential. Through magic and math, the ABS computer adjusts hydraulic pressure to each individual caliper. This MAGIC and MATH part relies heavily on the preprogrammed information of chassis weight, dynamics, and a whole bunch of other stuff that requires years worth of education to understand. When you lock two tires, (make them work simultaneously), the dynamics of wheel braking change outside of the program. ABS turns off because the computer believes there is a malfunction in the system somewhere, effectively rendering the system useless.

If you want more information in regards to ABS on S-Chassis look at the FSM under BR, Braking System, starting on page 22.

[jr_ss]

Originally Posted by oni jake

Dude, post something worth a damn instead of getting your post count up. Contradicting what I said with no logical reasoning doesn't help anyone. If by your logic there isn't a problem with running a welded diff on a ABS S-Chassis, then post possible reasons why his ABS malfunctioning light is on.

I corrected you, because you stated that ABS system would see that there would be "two" wheels locked, however there is only one sensor for both rear wheels...

It is possible that the sensor in the diff he has is faulty, causing the light to come on. Perhaps a poor electrical connection....

There are very few reasons the ABS light can be on, it's either mechanical or electrical, my guess is on the electrical side.

However, before you try anything, you should pull the negative battery terminal to clear the codes. Disconnect it for atleast one minute and see if it clears.

Me, a post whore, good god you're an idiot...

[oni jake]

Originally Posted by jr_ss

I corrected you, because you stated that ABS system would see that there would be "two" wheels locked, however there is only one sensor for both rear wheels...

It is possible that the sensor in the diff he has is faulty, causing the light to come on. Perhaps a poor electrical connection....

There are very few reasons the ABS light can be on, it's either mechanical or electrical, my guess is on the electrical side.

However, before you try anything, you should pull the negative battery terminal to clear the codes. Disconnect it for atleast one minute and see if it clears.

Me, a post whore, good god you're an idiot...

I love this. You have been trailing recent posts nit-picking a selection of words and posting nothing useful to anyone.

This what you sound like, "HAI GUIZ! I read watched a 2 minute youtube video on ABS systems and pulled the diff out of my 240sx once, so I am now the all-knowing authority figure on Zilvia. I hand out bad advice and ride the coat tails of other people's posts all the time, and no one knows the difference so I carry on with it."

And serious thought: you honestly think, sitting back all fat like in your computer chair huffing about your response to this post, that the S-Chassis ABS system cannot tell the difference between a open and welded diff with 3 sensors measuring 4 wheels? A welded diff LOCKS the rotation of two wheels changing the circumstances of how a car reacts to braking; throwing the static perimeters the ABS computer needs to properly work out the window. So I said before, if you want to actually educate yourself and help others on Zilvia, try reading the ABS section in the FSM then come back posting about how wrong I am.

[Darren]

abs and welded diff are contradictory, do what jake suggested

[rwtf]

[godsmack]

ok i'm confused with this one. i don't know much about abs but what part of the diff is the sensor reading?

[jr_ss]

Originally Posted by godsmack

ok i'm confused with this one. i don't know much about abs but what part of the diff is the sensor reading?

The pinion gear has a ring on it inside the diff that the sensor reads as it spins. If it sees the rear wheels spinning a percentage faster than either one or both front wheels under braking conditions it activates the ABS. It is a very simple system, far less advanced than the newer abs systems out there.

[KiLLeR2001]

Man this oni jake fella sure is try-harding today. I'd love the explanation of how the rear ABS sensor can tell the difference between a 2way, 1.5way, welded and open.

[godsmack]

that is why i started to get confused. with one sensor in the the diff you can not possibly be able to tell the speed on both tires. i read up in the fsm on this matter now and jr ss is correct with what is being said. even if the diff is locked the sensor is only reading the input to the rear. so with that being said you can have abs with welded diff as long as you have the same gearing and properly working sensor.

[godsmack]

^if that rear tire locks so will the otherside so the abs will have a correct reading. both will lock because of having a welded diff. if one stops they both do. it doesn't compensate for which one locks up first it compensates for the rear showing a lock up and then adjusts the pressure going to the sensor in which this would be the rear in general which is one line with a T.