Low Trac Light from 60-65mph after rear end swap...
#101
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Smg thanks for the post. As you can see, my sensor gaps are exactly 15 thousandths off from each other (close to your 0.020"). And my gaps are both close two double the stock gap (0.040"). All I want is my abs to work since I paid the extra money for the 4ch setup. How do you fix something that has the same parts that worked before, you can't blame it on my reused rings/backing plates nor new sensors.
So I just checked the gaps for the reluctor rings, cleaned the sensors and made sure they were in all the way. I checked for any codes on my buddys hptuner scanner and no bad sensors. I will be buying hptuners soon so I can recalibrate tire height and gear change. Trying to eliminate all your suggestions, thanks!
This is what they measure:
-Distance from back of the wheel stud to the ring is:
driver side: 0.035"
passenger side: 0.040"
-Distance from the sensor to the ring is:
driver side: 0.080"
passenger side: 0.065"
Looks like the gaps are way out of spec unless your got your measurements backwards?
here are pics of what I was measuring, these pics are of the driver side.
This is what they measure:
-Distance from back of the wheel stud to the ring is:
driver side: 0.035"
passenger side: 0.040"
-Distance from the sensor to the ring is:
driver side: 0.080"
passenger side: 0.065"
Looks like the gaps are way out of spec unless your got your measurements backwards?
here are pics of what I was measuring, these pics are of the driver side.
#102
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i dont recall the measured airgaps i had. I clearly remember they were 20 thou apart though. i think they were at 40 thou on the rr and 60 on the left. this goes back two year though. This shouldnt be a problem you have to live with. you just have to determine the problem and verify the measurments. the gap between the wheel stud and the reluctor ring didnt seem to effect mine either as an FYI. I have the 4 chn set up and used my original speed sensors and wiring on my 12 bolt with no issues to date.
let me know if there is anything else i can do to help.
let me know if there is anything else i can do to help.
#103
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From my experiences when I worked for GM most of the issues like people are describing here are caused by faulty connections, corrosion within the harnesses, or problems with the EBCM.
If the reluctor rings are not in contact with wheel studs, running true, the sensor gap is correct and covering the reluctor ring properly, there is no reason for the system to have any issues with producing the correct voltage. Air gap between the sensor and reluctor ring is crucial.
Keep in mind the wheel speed sensor is just an electro-magnet... they can become weak over time.
If the reluctor rings are not in contact with wheel studs, running true, the sensor gap is correct and covering the reluctor ring properly, there is no reason for the system to have any issues with producing the correct voltage. Air gap between the sensor and reluctor ring is crucial.
Keep in mind the wheel speed sensor is just an electro-magnet... they can become weak over time.
#104
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By truing up my reluctors I was able to get mine to work up to 65mph where previously it would only work to about 20mph. Just this weekend I went to town with a pry bar and dial gauge and got the runout down to 0.003". Ill let you know how it works when I get the trans installed...
BUT, as I was screwing around this weekend I realized my axles had about 0.005" slop in and out (along axle length) that i needed to account for. This got me thinking that the sensors must not care much about the space to the flange...how could they with a sloppy *** c-clip setup?
BUT, as I was screwing around this weekend I realized my axles had about 0.005" slop in and out (along axle length) that i needed to account for. This got me thinking that the sensors must not care much about the space to the flange...how could they with a sloppy *** c-clip setup?
#105
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Good point. In/out isn't important but rather forward/backward is. With my 12 bolt the sensors had to be ground down to fit as they were hitting the reluctor (too far in). I added some ingenious homemade spacers to them the other day. Yesterday I went for a short drive but the lights haven't gone off yet....I got my fingers crossed but my hopes down. I have not checked the trueness of the reluctor yet but will after I've exhausted other options.
#107
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I tried re-spacing mine and took a quick drive but it didn't reset itself. If in another drive it doesn't reset and return back to working I'm doing abs delete. Not gonna waste anymore time with this crap.
#108
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I know this is an old thread, but it is the only one I can find stating similar issues to what I have been facing.
Last year I installed a Strange S60 in my 2002 Camaro with ABS and TCS (4 channel). I had the same issues as the OP, but my low trac and ABS lights would come on around 85-90. If I hit the brakes at this speed or faster, the brake pedal would pulse like the wheels were locked up and hardly scrub off any speed, kinda sketchy. If I was going anything less than 85 everything worked like normal. This seems like a common issue when installing an aftermarket 4 channel rear end.
A few days ago I measured the air gap between the reluctor wheel and sensor. The drivers rear was about .080", and the passenger rear was around .060", which leads me to believe the housing was fabricated slightly off. To correct the gaps to around .040", which I am 99% sure is the factory spec, I had to grind on both the brake backing plate (where the sensor mounts), as well as the sensor itself in order to rotate the sensor closer to the reluctor wheel. After getting the sensor air gap set to .040", I put everything together and went for a test drive. I got no lights, and no ABS activation. I took the car to the top of 4th (roughly 120mph), and everything was good!
Hopefully this helps anyone having the same issue with an aftermarket rear end.
Last year I installed a Strange S60 in my 2002 Camaro with ABS and TCS (4 channel). I had the same issues as the OP, but my low trac and ABS lights would come on around 85-90. If I hit the brakes at this speed or faster, the brake pedal would pulse like the wheels were locked up and hardly scrub off any speed, kinda sketchy. If I was going anything less than 85 everything worked like normal. This seems like a common issue when installing an aftermarket 4 channel rear end.
A few days ago I measured the air gap between the reluctor wheel and sensor. The drivers rear was about .080", and the passenger rear was around .060", which leads me to believe the housing was fabricated slightly off. To correct the gaps to around .040", which I am 99% sure is the factory spec, I had to grind on both the brake backing plate (where the sensor mounts), as well as the sensor itself in order to rotate the sensor closer to the reluctor wheel. After getting the sensor air gap set to .040", I put everything together and went for a test drive. I got no lights, and no ABS activation. I took the car to the top of 4th (roughly 120mph), and everything was good!
Hopefully this helps anyone having the same issue with an aftermarket rear end.
#109
I am having the same issue with my MWC 9". The air gap is not something that MWC changed though. They are set by the backing plate (same ones I was using on the 10-bolt) and the sensor location in that backing plate (cam move around ever so slightly with the way the mount is designed). I am 90% sure that mine is caused by the reluctor ring not being true. I assembled my axles myself and that was a problem from the start. The factory 10-bolt alxe, where the reluctor rings get pressed on have a lip. So you achieve the same axle flange to reluctor ring gap on every axle. The issue with the MWC setup is the strange axles have the reluctor adapter and they dont have any lip that the reluctor rings get pressed up against. This leads to a few issues:
1. The reluctor is easy to be pressed on a little crooked and not run true.
2. The reluctor can be a little further or closer to the sensor depending on how far it gets pressed on (should be much of an issue though as C-clip type have some in/out movement that never caused issues)
1. The reluctor is easy to be pressed on a little crooked and not run true.
2. The reluctor can be a little further or closer to the sensor depending on how far it gets pressed on (should be much of an issue though as C-clip type have some in/out movement that never caused issues)
#110
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I am having the same issue with my MWC 9". The air gap is not something that MWC changed though. They are set by the backing plate (same ones I was using on the 10-bolt) and the sensor location in that backing plate (cam move around ever so slightly with the way the mount is designed). I am 90% sure that mine is caused by the reluctor ring not being true. I assembled my axles myself and that was a problem from the start. The factory 10-bolt alxe, where the reluctor rings get pressed on have a lip. So you achieve the same axle flange to reluctor ring gap on every axle. The issue with the MWC setup is the strange axles have the reluctor adapter and they dont have any lip that the reluctor rings get pressed up against. This leads to a few issues:
1. The reluctor is easy to be pressed on a little crooked and not run true.
2. The reluctor can be a little further or closer to the sensor depending on how far it gets pressed on (should be much of an issue though as C-clip type have some in/out movement that never caused issues)
1. The reluctor is easy to be pressed on a little crooked and not run true.
2. The reluctor can be a little further or closer to the sensor depending on how far it gets pressed on (should be much of an issue though as C-clip type have some in/out movement that never caused issues)
#111
I will have to check the air gaps as well. I wish I would have measured before I disassembled the 10-bolt for both the air gap measurement and the depth of the sensor over the ring. If yours is working with the 0.040" gap then that sounds like a good measurement to try and achieve.
If I am understanding you and a few of the other comments above, you believe that the axle housing end flange (where the backing plate bolts to) may be slightly off when MWC fabbed the rear? And that is causing the air gap measurements to be off both from factory specs and off between both sides?
Because even is that mounting plate is off center from the axle tube the bearings are forced into that and the backing plate is bolted to the same part. How could that cause the reluctor ring gap to be off?
If I am understanding you and a few of the other comments above, you believe that the axle housing end flange (where the backing plate bolts to) may be slightly off when MWC fabbed the rear? And that is causing the air gap measurements to be off both from factory specs and off between both sides?
Because even is that mounting plate is off center from the axle tube the bearings are forced into that and the backing plate is bolted to the same part. How could that cause the reluctor ring gap to be off?
#112
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If I am understanding you and a few of the other comments above, you believe that the axle housing end flange (where the backing plate bolts to) may be slightly off when MWC fabbed the rear? And that is causing the air gap measurements to be off both from factory specs and off between both sides?
Because even is that mounting plate is off center from the axle tube the bearings are forced into that and the backing plate is bolted to the same part. How could that cause the reluctor ring gap to be off?
Because even is that mounting plate is off center from the axle tube the bearings are forced into that and the backing plate is bolted to the same part. How could that cause the reluctor ring gap to be off?
#115
I have mentioned before in other post that everything 4ch that is being used is the exact same stuff that came off the vehicle as before as the 4ch combination is independent of the housing. Only thing that may not be factory is the reluctor ring if you purchase an aftermarket version but the ones we use currently look identical to factory minus color but a customer can use their factory ones. As for using the adapter for the 4ch ring, the adapter itself will firmly hold the ring in place but it has to be assembled in a certain direction and there is a stopping point on the axles themselves but not a positive stop and takes a little work to get it straight. Well unless you have done as many as I have it gets to be second nature.
Now for the housing being crooked. The housing could be a U and it would still not effect how the 4ch reads, it just needs the ring to spin and a sensor to read it. Not that this could happen for obvious reasons but you could mount the housing end ontop of the axle tube and it still just needs to read the reluctor wheel from the backing plate. As long as the backing plate is mounted to the housing end it should work. A wobbly ring can effect how it reads and this is where we get back to making sure it is 100% true when spinning. Another issue is you need to shave the sensor with aftermarket housing ends to fit and this step is often not done or not done well enough. This is do to the bigger housing ends to fit a bigger bearing. If you force it in the pick up portion will be at an angle and you need to make sure it is parallel with the ring.
We know 4ch can work because so many have a functional system after they purchase an aftermarket rear end. When we assemble the housing here all we see is the factory backing plates. We do not have the running moving vehicle to make adjustments if needed and can only give suggestions over the phone. At the end of the day these are aftermarket parts and even though we try to make it as simple as possible there are times tweaking may have to take place. These last few post shows that once installed and some tweaking on the installers end can solve these issues if they do come up.
#116
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i ordered my rear assembled and u guys took car of grinding down the sensors for me so i assume they are parallel......please post here where i need to "adjust" to make this work. i still need to measure my distances to see what they are at, now that i know to look for .040 or so
#117
If someone sends in their sensors which isn't very often as we ask for no extra parts with the brake backing plates/tin shields for less risk of losing parts during assembly as we have to completely dissemble the backing plates for assembly but if they do we will shave the portion down so it fits in the housing without forcing it in place hoping it stays attached for the delivery instead of putting it in a box that may get lost during transit which is another reason we ask for no extra parts on the backing plates. From there we no longer see what happens until the customer plugs it in and this is where fine tuning may have to take place to insure the ring is spinning true and the sensor gaps may need adjusting. Hundreds of customers walk away with a plug and play working system from the start others may have to make tweaks. At the end of the day it is still all the factory components used off the factory 10-bolt and as long as the sensor is above the ring that is all the axles and housing need to supply is the mounting point.
Different size tires, spool, non spooled differential locking up like a spool, powder coated backing plates, ground down backing plates during cleaning, bad sensors, deteriorating wiring, pulling wiring out of the plug during disassembly, not pushing the plug in completely on reassembly, bent backing plates, not using the tin shield, and so many other things to consider that may cause unforeseen issues. The final step is to make sure the wheel spins true and adjust the gap on the sensor until the system reads properly.
Different size tires, spool, non spooled differential locking up like a spool, powder coated backing plates, ground down backing plates during cleaning, bad sensors, deteriorating wiring, pulling wiring out of the plug during disassembly, not pushing the plug in completely on reassembly, bent backing plates, not using the tin shield, and so many other things to consider that may cause unforeseen issues. The final step is to make sure the wheel spins true and adjust the gap on the sensor until the system reads properly.
#118
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As an update from me I never adjusted mine any further, gave up and deleted abs. Never really liked it anyway. Glad to see some of you guys getting the issues resolved though.
#119
It is and has always been part of our rear end discussion when going over everything with the customer when discussing their order that 4ch may have quirks to operate properly and need tweaking once everything is installed. We have a master sheet we go off of for rear end orders full of questions to be asked and certain things to be explained and once we get to 3ch or 4ch we explain that it is not a guarantee to work and what you are paying for is the reluctor wheel adapter and the axles to be turned down to accept it from Strange. All though we have never had an issue with 3ch to date but I assume because it is a simpler system and only has to read one ring off the rear end and not two plus it is centrally located not out on the end of each axle.
#120
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Its definitely a finicky system IMO. Of course OEM stuff was never designed to be cutting edge, only just good enough to get through the warranty period.