stevo92z28

iTrader: (22)

Hi. I have a 2000 T/A with a 3 channel rear (no t/c). The used rear I am swapping in is a 4 channel out of a 99 T/A M6 with t/c. I'm not hooking up traction control or anything like that. I just want to know if my ABS will work correctly by going off the speed sensors on the wheels (4 channel axle).

Thanks.
Steve

keliente

iTrader: (22)

No it won't.

stevo92z28

iTrader: (22)

Personal experiance? Why wont it work off the wheels instead of ring gear?

keliente

iTrader: (22)

Because if you have a three channel car you do not have any sensors for the wheels. If you want to make a 4 chan work in a 3 chan car, you need to put your reluctor wheel on the new diff, drill a hole for the abs sensor, and install the sensor.

stevo92z28

iTrader: (22)

The 4 ch rear i bought, has the sensors on the wheels. Either way i guess your getting at its not going to work without the sensor on the ring gear.

So from the sounds...i have a very big paper weight now.

RE AND CHERYL

iTrader: (31)

The reason it won't work is because the reluctor on the end of the axle has a different amount of teeth than the one used on the ring gear. The ABS computer counts the pulses from these teeth and determines wheel speed.

You can make it work, but it will take some work.

Re'

camaroguy26

iTrader: (21)

there's a sticky that explains everything about it and how to change it to a 3-channel if you're up to the task

stevo92z28

iTrader: (22)

Now what if we have access to the ABS module out of the 4-channel car? Could the modules be swapped so that the pulses from the sensors would be interpreted correctly? Or would this cause a problem since there would be no t/c?

stevo92z28

iTrader: (22)

Right, though stripping the down carrier, taking it to the machine shop to have it drilled, installing the reluctor wheel on the ring gear is all stuff i dont have time for, as well as the cost for it all to be done. Just not worth it in the long run, especially on a 10 bolt.

camaroguy26

iTrader: (21)

pretty much your best bet then is to delete your abs

keliente

iTrader: (22)

That's only half of the equation, you'd also need the wiring harness. The issue is that your car's wiring harness only goes to the center of the diff with one plug. A 4 channel car has a split wiring harness that has a connector at each end for the wheel sensors.

It is a LOT easier to put a 3 chan rear end into a 4 chan car than what you are dealing with. If I were you, personally I would just drill the carrier & add the reluctor & sensor as opposed to making the car itself 4 channel, that would be a pain in the ***. If you don't want to deal with it at all just give up on making ABS work and pull the warning light bulb out of the instrument cluster. Also SJM manufacturing has a ABS delete kit you may want to look into.

stevo92z28

iTrader: (22)

Well already done, this is my gf's car and she made the choice to keep the ABS so i put the 2.73 rear back in the car .

I did have the harness that plugs to the wheel sensors and the connector on the body.

Im willing to pull a reluctor & sensor from another rear at a junkyard or go to the dealership for them and drill the housing. Any idea how much a machine shop would charge? Is this a common thing? Because i may call up a machine shop tommaro but i wonder if they would know what im talking about.

Appreciate the help.

The car needed gear so bad...guess its gonna have to wait.

stevo92z28

iTrader: (22)

Theoretically we "could" swap to 4 channel though, just get the module, harness(already have) and then also 4 channels has 2 rear brake lines going all the way up to the front of the car into the module right? Because the brake lines were different on the 4 channel it didn't have the single T-split line like the 3 channel rear.

keliente

iTrader: (22)

I'm not sure how common it is, but I do know that more than a few people have adapted a 4 chan for their 3 chan car. Alamantia's thread has good details about the specifics of drilling/tapping:

https://ls1tech.com/forums/gears-axles/617761-converting-4-channel-3-w-pics.html

Theoretically you could make the car 4 channel, but I really do not think it would be worth the headache of changing EBCM, brake lines, wiring harness, etc. Then also what would you do about the TCS switch on the inside of the car? Your 3 chan car wouldn't have it and I don't think the body wiring harness has a provision for it if the car didn't come 4 chan...

MysticTealTA

iTrader: (1)

I thought I would pipe in since this is my car that Stevo is talking about. I've read Alamantia's thread/sticky several times. We have all the wiring, sensors, etc etc for the 4 channel rear, the ONLY thing we do not have is the EBCM, but could easily get it as all this is out of a friend's car. I don't give a hoot about TCS and have no intention of putting that in my car. Would the 4 channel EBCM be able to be hooked up without TCS and have ABS work? Otherwise I need to figure out if I'd rather a) have 3.42s put in my current 2 series rear or b) pick up a spare ABS sensor and reluctor ring and have the hole drilled and machined into the spare 4 channel rear.

keliente

iTrader: (22)

4 channel cars are ABS/TCS, and you can't exclusively use ABS. If the system is not 100% functional, you don't have either. So no, the 4 channel EBCM would not be able to be hooked up without TCS and have ABS work.

If you think about how the systems work, it will probably make more sense. Three channel = the car sees three signals. One at each front wheel, and one that measures both rear wheel speeds collectively, via the sensor on the pumpkin. Because it can compare the speed of the front wheels to each other and to the speed of the back wheels, you have ABS. Now with 4 channel you have a sensor at each wheel. So in addition to the aforementioned, you are comparing one rear wheel to the other - so it senses wheel slip in order to add traction control to the matter. So you can't seperate ABS from TCS in a 4 channel car. Either they both work or neither of them work.

It would be far easier to have your housing drilled to accommodate a sensor and have the ring gear's reluctor installed. You're looking at an hours labor at best from a machine shop (if you can't do it) and maybe an hour or two by a mechanic to get the reluctor on (won't even require resetting any rear end tolerances, just reassemble and disassemble).

If you try and make the car 4 channel then you're doing several installs besides the rear itself - including the EBCM (sort of a pain IMO) brake lines which are going to require rebleeding the whole system, adding in that wiring harness, and the question I posed before; which was is it even possible to add in the TCS switch to the inside of the car (to allow it to be disabled).

Just my .02. You could always sell this rear and get another one, 3 chan.

keliente

iTrader: (22)

Or heck, if you want to go with option a, go for 3.73s, which is what most folks with A4's go to.

stevo92z28

iTrader: (22)

3.42 is a lot better gear all around in my opinion. Its not a drag car. The car sees 100% street and a lot is highway 3.73 is too much for A4.

Thank you for answering the question though. That the 4 ch ABS will NOT work without T/C and since that is the case i wont even be attempting that.

What do you think the chance is of finding a 3.42 3 ch car? 01-02 all were 4 ch correct? That means itd have to be a 98-00 6 spd car without T/C...doesnt sound too common?

keliente

iTrader: (22)

Channel is not based on year. 3 and 4 channel were offered for all years 98-02. So basically you would just need a 6 speed 3 chan car, 98-02 to get the rear you want.

2 SSlow

iTrader: (26)

I put a 3 channel rear in my 4 channel car because it's the only rear end that was laying around when mine took a ****. All i did was take the abs harness off for the rear end assembly. The car doesn't drive or stop any different than it did before. I have driven in the rain, and on dry ground and can't tell the difference. They have only locked up 1 time in a hard stop, i lifted slightly and got back into the brakes and all was well. If you know how to drive, or if you're confidnet with your driving there will be no problems. There are still millions of cars on the road without abs...**** my dads base modle 2004 impala doesn't have abs. But you're talking to someone who deleted traction control too. lol