[ram190]

Had 265/75 BF ATs put on yesterday, noticed at about 35 mph and above when I turn the "slip" light comes on and the ABS starts to tweek? Any input?

 

[S_e_X-Terra]

thats pretty strange. Never heard of anyone having that problem. Make sure that all four tires are the same size. For some reason that is the only thing that I can think of that might have happened.

 

[ram190]

They said that the air presure sensor needed to be re-set, but I don't think that would have anything to do with it-- struck me as very odd. All tires are 265/75. Never had the problem with the OEMs.

 

[S_e_X-Terra]

no way its the TPMS (tire pressure monitoring system) that is a totally separat electrical system than the ABLS (automatic braking limited slip). You might have a electrical problem, or you might even have a problem with your rear diff.

I think that someone else like lloydswartz who has had rear diff problems might be of some better help to you.

 

[JtaoJ]

Even going to larger tires the problem you describe does not happen. Check the lines at the wheels to make sure they didn't bugger something, and then it sounds like warranty time if nothing is visable. You don't want the issue to cause some unsafe braking, etc.

 

[Muzikman]

How sharp is the bend? My guess, you are going too fast for the corner.

The BFG AT's have a stiffer sidewall than stock. This prevents tire roll, there for instead of rolling over on the sidewall like the stock tires would do, they are probably skipping on the road surface.

It's not the ABS going crazy, it's the VDC.

Oh, and check the air pressure, make sure it's not up in the 40's or higher. An over inflated tire can also do what I described above.

 

[willgr1]

i get the same thing, but it's if i take a bend on the highway too fast or i'm in wet conditions.

 

[Mark]

I havent had any issues. If i drive over a curb, or some wet road and try to go to fast too soon, i get the "slip" showing up. But never the VDC.

 

[Muzikman]

The slip light is the VDC in most cases. The only other time the "Slip" light comes on is with the ABLS, and unless you are drag racing, that probably won't be kicking in on the street.

 

[d-rap]

Even when I turn the VDC off manually, I get the ABLS kicking in occasionally when I take turns hard on a windy road. Driving under load increases this tendency, of course. This has happened to me sometimes both before and after I lifted my X and went with a wider track. If you take turns fast, even though they may be well within the capability of the X, you will get a "Slip" indicator and ABS flutter.

I really agree with Muzikman about the stiffer sidewalls and tire pressure being factors here. Overinflated tires especially will be less tractive and forgiving, and will slip more easily.

 

[Muzikman]

I am shocked the ABLS would kick on going around a bend. That would counter act the diff and want to pull the vehicle straight. That could be kinda scary.

 

[d-rap]

It's markedly worse since my lift--my half-shafts are 2.5" longer than stock. Maybe the computer needs to be reset. But as I posted, I've always had it kick in occasionally as I'm accelerating through a turn with the VDC off. It feels like its braking the outside rear wheel as if to counteract oversteer. I wish I could override it manually. If I back off the throttle, of course it subsides. And I'm not talking crazy fast either, just typical mountain driving. Dealer says it's normal. Anyone else know what I'm talking about?

Could it be that the ABLS/VDC is designed to synch up with the diff somehow? Perhaps not though, since presumably the diff makes "decisions" on the basis of wheel rpms without computer intervention. Or maybe the ABLS braking becomes input for the diff, which it can handle? Thoughts?

 

[Muzikman]

ABLS uses the ABS sensors to detect wheel spin. If it sees one wheel spinning much faster than the other, it grabs the faster spinning wheel to slow it down to transfer power to the slower spinning wheel.

The only input the diff has on this is doing it's thing as an open diff, allowing one wheel to spin faster than the other when you go into a turn. The outside wheel needs to turn faster than the inside wheel.

Now, sure, it sounds like the ABLS is doing it job, but in the wrong case. my guess, if this is happening, the computer needs recalibrate. My guess though, there is nothing they can do for aftermarket suspension / tires, just like they can do nothing about the speedometer for oversized tires.

Your wider track would change this effect, so I can see it happening more now, but I have no idea why it was doing it before.

 

[d-rap]

Thanks, Jason, that's helpful as always.

BTW, I missed this site! I've been busy and distracted with work and working on my Jeep.

 

[ram190]

Thanks for all the input. They are 10 ply ATs, and it just happens that it is the first morning that it did freeze. So, I'm thinking that maybe the tires were slipping a little, but I couldn't feel it, and the VDC was kickin' in. I've driven the same with the rugged trails and no effect on the VDC? All tires are at 35 psi with Nitrogen. Again, all the info has been great.


Update: Drove home today from work with no problems, even tried to make it happen again. Must have been the fine layer of frozen precip on the road.

 

[lifeinthesouth]

It's markedly worse since my lift--my half-shafts are 2.5" longer than stock. Maybe the computer needs to be reset. But as I posted, I've always had it kick in occasionally as I'm accelerating through a turn with the VDC off. It feels like its braking the outside rear wheel as if to counteract oversteer. I wish I could override it manually. If I back off the throttle, of course it subsides. And I'm not talking crazy fast either, just typical mountain driving. Dealer says it's normal. Anyone else know what I'm talking about?

Could it be that the ABLS/VDC is designed to synch up with the diff somehow? Perhaps not though, since presumably the diff makes "decisions" on the basis of wheel rpms without computer intervention. Or maybe the ABLS braking becomes input for the diff, which it can handle? Thoughts?

Dave, I have the exact same thing so you're not alone... I jsut back off the gas.
No front sway bar (no sway bars at all for that matter) probably doesn't help.

 

[d-rap]

Thanks for the second. Good point on the deleted sway bars.