Ok, i made a post about this a while back. Installed a 3 channel diff from 00 SS in my 99 Z28, thought it was a Torsen, but just found out today the Torsen was my old 4-channel from my 99 Z28. The 00 SS is a 3-channel Auburn LSD.

I like gear lockers, but there is a lot of info saying that the Auburn is better than the Torsen. They both are 3.42 gears.

I want ABS in the Z28, as it will be my travel car, driving to heliports for the oilfield. Can I take something out of the SS to make the ABS work in the Z? The SS has a Traction control button but the 3 channel wont support TC, i think...

Could a tuner enable ABS with the 3 channel diff?

Both brake systems have 2 lines running from the ABS unit to the rear diff..

Thanks for the help...

Jay

 

clarify some terms first.
Auburn,Torsen are the differentials.
Rearend,complete,contains gears,axles and a differential.
3 channel ABS has a reluctor ring on the differential with the sensor on top of the rearend housing.
4 channel ABS & TC has a reluctor ring on each axle end and a sensor in/at each backing plate.

your post was a little confusing. So you put what(from what kind of channel car) into what(to what kind of channel car).

the SS traction control car needs a 4 channel rearend for even the ABS to function.

 

Put a 3 channel from a 00 ss into my 99 Z28. The SS 3 channel has 2 brake lines on the diff.. and looks like it had ASR.

I gave the car away yesterday, but the guy is going to swap out the ABS/EBCM with me tomorrow.

Hoping that helps, might take the throttle cable linkage.

All I want is ABS to work...

 

ABS ONLY will not work/function in a 4 channel system car. It is a common misconception that 3 channel ABS and 4 channel ABS electrical and hydraulic controls are the same,THEY'RE NOT. 3 channel ABS has one brake line running from the ABS module to the rear where it's split with a tee to feed both rear brakes. 4 channel ABS/TC has two brake lines running to the rear,each one feeding its' own rear brake caliper.
You can get your ABS(and TC) operational by installing the axles and backing plates from the 4 channel rear into/on the 3 channel rear.
An ABS 3 channel system,when ABS goes into activation,releases brake pressure until all reluctor rings(3) are in unison,then allows more braking(that's the pulsations of ABS)
An ABS/TC 4 channel system(4 reluctor rings) has 3 things it'll do. Releases brake pressure(ABS aspect),pulls back throttle(TC aspect),and supplies brake pressure from its' own pressurized reservoirsABS & TC aspect).

You've encountered a common problem when swapping complete rears.Yours is the easier to correct with the axles and backing plates.The other way(converting a 4 channel rear to use in a 3 channel car) is near impossible as rearend housing machining is required.

 

Well the doner car had a reluctor ring on the ring gear, none on the axles. It had ABS and TC.. Has the throttle assembly with the motor in it for TC, same as my 4 channel Z28. The SS also has 4 brake lines all the way back.

The guy i gave the SS to came by and we swapped ECBM's. If that don't work i'll just pull the light bulbs and pretend its 1989 and ABS wasn't around

I've heard that there was a 3 channel with ABS/TC and 4 brake lines like my doner car

 

Sounds to me like the doner car has had the original 4 channel replaced with a 3 channel from an LT1 car at some point. This is common since the LT1 3 channels are easier to find... also explains the Auburn diff.

You can convert your car to 3 channel but its a PITA. Getting the 3 channel EBCM and 3 channel rear is half the battle really though I suspect what you think is a 3 channel EBCM is actually still a 4 channel. Easy to tell by looking for the number of fitting exiting the back of the block... 1 is 3 channel and 2 is 4 channel. So get that straightened out first. If you need a 3 channel EBCM... PM me and I can set you up. Have an extra sitting in my garage from when I made this transition.

You will only be able to use 1 brake line to the rear so pick the line that has the female fitting at the rear axle. If the 3 channel rear is using 4 channel brake lines which it sounds, you can either convert those brake lines to 3 channel (PITA) or buy new 3 channel lines. If you are lucky and the 3 channel rear has the T-block bolted down right next to where the ABS sensor is located (top of center section) then you won't have to worry about getting 3 channel brake lines... though like I said I bet that silver car has the 4 channel plumbing on a 3 channel rear meaning brakes worked but no ABS or ASR. Might also explain why that SS rammed another car up the ***! If you have to buy new lines just make sure you get them for an LS1 car because LT1 lines use different sized fittings.

Anywho, once you get the rear brake lines figured out... you will also need to find an adapter that goes from the body line to the T-block line. Now you are dealing with 2 bubble flare fittings back there but the only adapter I could find went from a double flare down to a bubble flare so I had to rent a brake line tool that allowed me to convert that bubble to a double flare (on the body line)... very easy job. Just an FYI there. You might get lucky and find the right adapter though I couldnt and looked everywhere. Once that is complete, you will have rear brakes at least.

Next you need to get under the dash to unhook the traction control computer. Its mounted up above the steering column directly below the cluster if memory serves me... just unplug it. Nothing else required there but you do this to kill the ASR, low trac and ABS light.

Last bit of work is under the hood. On the wiring harness that plugs into the EBCM, find the green wire located at the #4 pinout and move it to #3. This will get the speed sensor signal working from the right front wheel. Then find yourself a 3 channel throttle and cruise cable and you should be in business.

I have 100% functioning brakes and ABS so this method works. If you follow the instructions and still get an ABS INOP light its because of a bad speed sensor or weak signal.

 

As was stated, just swap backing plates and sensors from a 4c car and the system will resume functioning

 

This would work as well, however, he stated he already sold the car. He needs to know other options are available which don't involve tying to locate and purchase another 4 channel rear with correct gear ratio. Took me over a year to locate a 3:42 rear within driving distance when mine was going out. I had to settle on a 3 channel and my old axles were pitted so I couldn't keep them.

 

If it was easy everyone would do it!