Wheel sensor or something else? [Solved? Not Really]

fozzi58 said:

OK so here is a weird one. My truck was recently lowered again, about 1" and mechanic was able to pick up about -1.5 camber with the Belltech coil overs. I also went down from 24" wheels on 305/35 to 22" on 295/35. On hard left turns at 40mph or higher, it feels like the ABS is kicking on for the right caliper. It feels like the suspension is "wobbling" during the turn but if you pull over and yank on the wheel etc, everything is solid.

I passed tech inspection Sunday when I raced but didn't think much about it but I did notice my left hand turns almost felt like they were a bit slow on the course. It wasn;t as noticable on the couse cause its a rough parking lot and you are accelerating and slowing down to get around the cones.

While changing the geometry of the suspension obviously changes the handling characteristics, I don't think that wobble is suspension related and I think the ABS may be kicking on, during those sharper left turns. It seems to only happen on left turns where it feels like the truck gets a slight "yank" to the right thru the turn. I did a couple of hard rights on exit ramps and I don't get the same sensation thru the steering wheel or body roll.

I have not programmed the new tire size in yet but the last time I switched to the race wheels for longer than the track event, it only messed up my cruise control not working (and the obvious mismatched speedometer). I'm thinking wheel sensor. My mechanic says possibly the wheel bearing if not the wheel sensor.

Side bar - I was going to pull the ABS fuses on my ride home from work today and see if I get that same reaction on a hard fast left. However, I am a bit skittish about pulling the ABS fuses only cause I don't know if the brakes will actually work. Not something I want to try on a public road? Maybe I should go find an empty parking lot? I'm old enough to have driven cars that don't have ABS so its not a frightening aspect to me - I am just worried that if the ABS is disabled, my foot will end up on the floor and only the e-brake to stop.

SO I guess 3 questions remain. Will the truck stop if I pull the ABS fuses (ABS system, ABS pump fuse). Do you think this issue is a dirty\bad wheel sensor or should I be going for a hub bearing?

I have another AutoX event Saturday but more importantly my first road race track event on the 12th which is what I really want to be prepared for. Suggestion welcomed. Thanks in advance....

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Marky Dissod said:

If ABS stops working for whatever reason, your brakes will work like your dad's did.

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fozzi58 said:

UPDATE 2

Replaced wheel bearings - didn't do anything.

Pulled ABS fuse - couldn't drive the truck cause puling the ABS fuse (fuse #35) disabled driver assisted steering - WTF? Its almost like having manual steering, not quite as bad, but it doesn't turn like I need it to. It would be a lot of hand over hand on a high speed turn.

Disconnected one of the wheel sensors on the spindle. Threw expected codes, disabled ABD, park assist, TC, but also said Driver assisted steering was reduced. hmmm. Took her out for some spirited driving.

Gawd DAMN! This beast can make turns! I had a rough day doing AutoX on Sunday and now I know why - the ABS must have been kicking on like crazy and I didn't notice it on the dash even though I felt it in the turns. I'm not even exaggerating when I say my Burb will kick my TA's ass on a turn. I haven't even played with the compression and rebound yet on the coil-overs but its like driving a train. The turns can just keep getting sharper and faster...and it wants more. OK enough bragging.....

Anyways - I've been doing a deep dive on the interwebs for the last 3 hours and looks looks like Vette's and Camaro's are facing somewhat similar issues. Basically the ABS's algorithm is sensing "ICE" so it starts applying braking etc. I am quite sure that the stabilitrack algorithm in the SUVs don't have any "track mode" settings hidden inside.

So basically I am going to be forced to run with an ABS sensor disconnected in order to drive aggressively. The super grippy Eagle F1s, with the lowered stance, stiff suspension and ridiculously capable cornering ability are too much for the factory Stabilitrack to handle. I will have to reach out to HP Tuners to see if some of this can be tunes out thru torque management or some other method. The only other option is to put a manual switch between the gyroscope and the computer and manually disconnect it.

If anyone else is crazy enough to turn their SUV into a track machine, I'll leave whatever findings here in this thread. Maybe I can save someone from wasting a $1000 on wheel bearing they don't need.

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Doubeleive said:

yep nannies suck. I would experiment with pulling other fuses instead in the meantime, maybe traction control.

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Marky Dissod said:

If ABS stops working for whatever reason, your brakes will work like your dad's did.

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Doubeleive said:

ya, but that sucks, if it does it intermittently it can do more harm than good

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Marky Dissod said:

You may be right about that. I remember when ABS used to wait until the tire stopped spinning, as in, it let the tire lockup before unlocking it.
End result was that large skids became smaller skids, instead of not being skids.
ABS still does the above, but it has also become far better at not quite locking up in the first place,
which actually helps prevent skids and gives the Stability Control one less thing to do.

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Doubeleive said:

to me it becomes a hindrance when it is not working properly, like when you are braking and expecting a certain result and that does not happen,
it just has a spasm and fails to perform as expected, then you are forced to take other corrective action.
On a track all alone that may simply result in running over a cone or barrier or getting your timing messed up,
but on the road that's a potential accident waiting to happen.

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