SOLVED! Slow speed ABS activation... :-(

[budwich]

The truck developed this issue in early december but I left it as other things were "scheduled" plus the weather isn't always nice. Anyway, I started to look at this as the low speed abs is annoying and maybe it ain't good for the system (ABS) in the long term.

Read some threads on similar issues to get some ideas. Did some electrical tests (impedance and ac voltage). The resistances were around 1K, one slightly less and one slightly more. Spinning the wheel by hand gave me some voltage ... not a lot as trying to speed the wheels (with tire / rim off) doesn't really get much "spin". But It did generate some voltage from each. I listened to the hub while spin the rotor (brakes removed so no contact / rubbing). The spins wire quiet / smooth and didn't detect any roughness. I could not cause any "reflects" when with the tires on and trying angular "twist". I did notice that the driver's side seemed to be harder to spin (without wheel) compare to the passenger side.

I posted this thread when I did the hubs back when.

watch out... its a drone... not that kind of a drone..

My truck (2008 4.2 TB) has developed a drone. It becomes noticeable at about 40mph and up. It is coming from the front end. Its not dependent on engine rpm and shifting between D and 3rd causes no difference as does removing the gas. There is no detectable difference in cornering in terms...

gmtnation.com

As you will have read, the passenger side hub was done twice as the replacement hub only lasted about 1 year (no name brand). I had kept one of the old hubs and used that as a replacement of the replacement. Everything has been fine since until this past few months.

I don't have a tech2 to read anything in terms of abs data. I have to still connect and do a cargage? ... app that can read codes for some of the non-engine units.

I am thinking that the initial replacement on the driver's side is now a problem due to its "stiffness" in the "spin test".... or is there some other component that could have contributed to the "binding" during the spin test and I am just gambling that one of the hubs is bad?

Thanks for any comments / ideas.

This should probably be moved to the technical section as opposed to the engine / drive train... sorry.

 

[Mooseman]

Since we're practically neighbours, you could come over and I can use either my Tech 2 or my new scan tool. We just need to see which wheel is dropping out at low speed.

The ABS light isn't coming on? It doesn't disable itself when it detects low speed activation from the same wheel? I did get that on my 2006 Saab once and it turned off the ABS and gave a code. Either way, it's likely a hub.

 

[budwich]

Since we're practically neighbours, you could come over and I can use either my Tech 2 or my new scan tool. We just need to see which wheel is dropping out at low speed.

The ABS light isn't coming on? It doesn't disable itself when it detects low speed activation from the same wheel? I did get that on my 2006 Saab once and it turned off the ABS and gave a code. Either way, it's likely a hub.

Hey Mooseman...
I could probably take you up on that "offer". I will continue in a conversation with "logistics".
There is no abs light... just the action. There is also an occasional "stablizer traction control" action that happens, usually on backing up and then shifting to move forward with a turn.... but I haven't figure out when or how that happens because it doesn't happen all the time.

Anyway, I would like to pinpoint the probable hub problem as I don't want to have to do both (again) if I don't have to.

 

[Mooseman]

The Stabilitrak could be a reaction to the bad ABS wheel signal it's getting. We'll look into it this weekend.

 

[mrrsm]

Do ALL GMT360 Vehicles sport the StabilTrack System?

GM's Official On Topic Video:

More Information...

Chevy Trailblazer Service Stabilitrak (11 Causes + Fixes!)

In this post, I will try to provide a comprehensive overview of why Stabilitrak failed, resulting in the Service Stabilitrak warning light appearing on your Chevy Trailblazer dashboard.

motorhungry.com

 

[TJBaker57]

Do ALL GMT360 Vehicles sport the StabilTrack System?

My 2002 Trailblazer LT does NOT have Stabilitrak. Perhaps it is not possible when the vehicle does not have 4 independent wheel speed sensors?

 

[budwich]

4 independent wheel sensors ??? maybe 2 plus driveshaft...

 

[TollKeeper]

4 independent wheel sensors ??? maybe 2 plus driveshaft...

2002-2004 had 3 sensors, 2 front, and a driveshaft.
2005-2009 had 4 sensors, 2 front, 2 rear.

This is why a replacement axle from a 2005-2009 will work on a 2002-2004, but no the other way around.

 

[Mooseman]

Pretty sure Stabilitrak started in 05 along with the 4 sensors. 06+ for sure.

 

[budwich]

Maybe I am looking in the wrong place.... wasn't thinking that there was sensors on the back. Maybe when I did work on the rear upper control arms in the fall, I might have disturbed things. More crawling around to check things. :-( lucky the upcoming snow will only stay for a few days

 

[budwich]

With the help of Mooseman's scanner, we were able to quickly see that the left front sensor was slow to pickup "speed" and quick to drop "speed". The other three were OK. I guess I am heading for a hub replacement... hopefully, finding one that will last a couple of years and not cost an arm of leg. This "bad one" was an ebay "pair buy" for $100. The right side only lasted about 1 year while this got about few more. Thinking of chancing "a-premium" as a crap shoot at this point, as reading various comments every where, it appears to be a crap shoot on every make depending.

 

[Mooseman]

We talked about Mevojunk so you know my feelings about them. SKF seems to have taken a nosedive in quality. I had a really bad experience with Raybestos years ago. Timken has never let me down however it's not the same story for everybody.

Seems we can't buy anything quality. This thread also talks about different brands:

Power Stop/Kinetic wheel bearing hubs?

I'm usually a big Timken fan for hubs but money is tight right now and I have at least one going bad with the usual noise and the other possibly bent. Was looking at cheap alternatives and found these on Amazon...

gmtnation.com

 

[Mike534x]

I couldn't ever recommend SFK again as far as hubs go, mine lasted roughly 20k (installed during COVID) before the actual internal bearings were failing. We'll see how long the SFK blower motor lasts that I installed last summer.

When I bought the Envoy in early 2017, I had Moog hubs installed upfront. Those lasted 8 months, and the Timkens after got me into about early 2020 before I installed SFK (based on them being highly reputable) and for the price they were inbetween the Moog/Timkens. Fast forward to October, one side is beginning to fail, and soon after the other (both bearings were making noise). Bought a Moog that was on sale, and a Timken. Got about a month and half in before the Moog hub had an issue with the speed sensor losing signal, and triggering the low-speed ABS. Sent it off to be warrantied, and snagged another Timken.

After looking over the prices, the Timken's aren't that much more expensive and its just worth it to spend the extra few bucks to get what is essentially the OE varient. I still use Moog for balljoints/end links, but their hubs are absolutely trash. Its perfect if you're in a bind, and need to get back on the road "today" situation but long term wise, don't expect them to last as long as you would like.

 

[mrrsm]

Concur... So much so... that in light of our rapidly changing world in which Printing Technology allows The Nefarious to use High Quality Printing *Fakery* (...if you look closely ...there is a "U" somewhere inside of that Word) that I decided to pull out my Timken Spare Hub to perform this Un-Boxing and create a decent Photo-Play of a Genuine Timken GM-GMC Truck Wheel Hub.

These images are meant to memorialize what the "Real Deal" Timken Hubs and what its Shipping Box should look like when you can compare all of these Earmarks (and OEM Label Water-Marks) vs. whatever is being sold on either Amazon or eBay arriving at your doorstep.

This one is for the GM-GMC Full Size Trucks (GMT800). The Cardboard Boxing for this Orange & Black colored container (my very FAVORITE Halloween Color Combo) is VERY Strongly Made... so if the Hub arrives in anything that is *Flimsy Packing & Shipping* that feels like what reconstituted Human Skin might be...Then start to get Suspicious of the Pedigree of whatever that Box holds inside...as THESE Hubs are supposed to be "Made In The USA":

 

[budwich]

The crap shoot is on with a-premium... I hope that doesn't mean "a-premium sucker". anyway, hopefully it will arrive sooner than later as it is an ONT seller. I need to toughen up my knuckles again...

 

[Mooseman]

Do you have a link?

 

[budwich]

Do you have a link?

https://www.ebay.ca/itm/31405288194...=0&customid=link&campid=&toolid=20001&mkevt=1 ... fingers crossed and bandaided

 

[TollKeeper]

I have had good luck with Detroit Axle Hubs... But nothing else from them. They are cheap, and offer a 10yr warranty.

 

[budwich]

The hub showed up today (canada post). It looks like "steel"... not sure I would know the difference in a "glance".

Anyway, I will probably get to it on the weekend.... I can hardly wait...

ADDED: Just did a quick table top test.... impedance is about 1.1k ohm while a brief hand "twist" easily provided 100mv of voltage. It seems to spin smooth, hard to tell if its easier or harder than the one currently on the vehicle.

 

[budwich]

Well, the weather allowed me to move my truck up in the "to do" list. My previous install and use of anti seize on the bolts made for an easy disassembly. New hub in, and ABS is now fine. Consider this solved.

Big thanks to Mooseman for the scanner sensor speed data that helped pin point the issue. I hope to pull the sensor on the old hub to see what's up there. The hub seems to turn "reasonably" well so perhaps its only a rust issue as Mooseman had mentioned about the rust under the sensor body causing it to slightly lift from the seating.

 

[budwich]

I got at the sensor on the old hub. attached is a picture of the shims and the sensor body. As Mooseman suggested, it is quite possible that rust ingression on the shims caused the body of the sensor to lift enough to cause a problem with its "detect distance". The shims are quite thin, maybe a couple thousands in thickness. In the picture, you can see one of the outer shims is fairly rusted across its interior face. Also not helping is the fact that the sensor is only held in place with one screw so it is possible that rust "blooming" can "lever" the sensor end away from the body of the hub. At "thousands" in the "equations", it probably doesn't take much.

I will probably clean things up a bit and put the hub in my "spares shelf" (otherwise known as my whole garage... ).

 

[Mike534x]

Its definitely a bad design, I would've much preferred seeing a double screw setup holding the shims down. After putting mine in (after following what Eric O does), giving the sensor area a nice spray of Fluidfilm to hopefully slowdown/prevent it from rusting out too much in the future.

 

[budwich]

The "teeth" on the hub "spinner" were nice and shiny, like new. The sensor itself was clean. I guess they set the shim spacing up at the factory when setting the bearings in place but it got to be really really close. Maybe, with even a little bearing "wobble" is enough to completely drop the voltage in my case, internal "rub" somewhere in the final moments.