'97 AWD death wobble (front)

[CDW6212R]

Hi Hacra,

All I am saying is that you should try is removing the 2 old ABS Sensors, clean them off and put them back on. At this stage/point, I am not saying you should go out and buy new sensors. With regards to your old ABS sensors - the "faces" of these sensors get contaminated with a coating of fine ground metal dust. The metal dust contamination will cause the ABS system to not work correctly. That's why it's worth a try to remove and clean them, as more than likely they have never been cleaned.

REAR ABS SENSOR: The rear ABS sensor is 1 BIG sensor located on top/passenger side of the rear differential. 1 bolt holds it down. After you remove the 1 bolt, you remove the ABS Sensor by twisting it right/left while at the same time pulling it upwards.

The front ABS sensors on 2WD's are external and need cleaning occasionally. The front 4WD/AWD sensors are internal, bathed in grease, they never need removal.

 

[Mbrooks420]

You might be able to remove the sensors on s rust free CA vehicle, but if the vehicle is driven where they salt it is very unlikely you’ll get them out of the factory hubs.

 

[fast_dave]

Just saying -

What I have experienced, the 3 ABS Sensors are essentially electro-magnets, and thus cling to any fine metal particles that are present due to worn metal components.

I clean all 3 of them regularly as a part of my bi-yearly preventive maintenance, and they are always dirty.

Additionally, I perform bi-yearly brake fluid flush with Valvoline DOT 3/4, and keep my caliper pins well greased with synthetic brake grease.

I firmly believe that due to these preventative maintenance measures, my 20 year old ABS system works perfectly; my stops are straight and short.

 

[Mbrooks420]

My ABS works great, an my wheel bearings are factory, and sensors have likely never been removed. As long as the Hall effect can pick up the solid metal “teeth” of the tone ring it doesn’t matter if they are dirty.

 

[CDW6212R]

I did take my original ABS sensor out of the first left hub I changed, thinking it had to be removed to get the hub off. The sensor was covered and filled with transparent green grease, factory with 98k miles.

I learned on the next one to just unplug the sensor at the frame connector, and unbolt the 8mm hold down bracket on the spindle. That sensor was like new, just covered in grease. I kept it as a spare for a few years, after about the 3rd hub I realized they all come with the hub, and aren't going to fail unless the hub does first. I threw away that spare front ABS sensor in about 2005 when I rebuilt the entire suspension. The 4WD/AWD hubs are great to know the sensors are a non issue.

The 2WD sensors are more fragile, I have had to replace three on my Crown Vics, when the hub bearings went. On those if the bearings wear enough, the rotor will contact and bend/eat the sensor, the ABS light comes on then.

 

[J_C]

The front ABS sensors on 2WD's are external and need cleaning occasionally. The front 4WD/AWD sensors are internal, bathed in grease, they never need removal.

Untrue! A month ago I had my front left sensor go bad on my '98 4WD. "Maybe" it just needed cleaned off, but since it broke apart trying to remove it (carefully too!) it didn't matter, a new sensor was needed.

Forscan app plus an OBDII dongle can read the ABS sensor data to see if one, and which one, is having a problem.

Maybe my hub is going out, I made a topic asking about that, but so far it makes no noise, has no play, spins normally, and replacing the ABS sensor resolved my issue which was ABS activation around 5MPH slowing to a stop. Granted I've only put 100 miles or so on it since that repair but it was activating every 5th stop or so which has completely gone away.

The hub-sensor interface is a bad design with the only o-ring down 2/3rds of the way on the sensor shaft and no gasket at the top so water can get down in there and rust away the hole. I put some silicone grease on the new one to slow that down if not stop the rust.

Anyone who deals with rust on their vehicle in general, there is a high chance that trying to remove the sensor will break it. I would not pull them to clean them until you have Forscan app data about which one it is, otherwise I would have replacement sensors handy so you're not messing around with taking it all apart again to put a new sensor in, or leaving it disassembled waiting on one through the mail (local auto parts store prices are outrageous for those sensors considering what they are)... they only cost $10/ea ($20 for a 2 pack) on Amazon.

EDIT: I'm a little off on the Amazon price, I got a 2 pack for $20 as an Amazon Warehouse Deal, normally they're closer to $16 for 1 and $30 for 2. Example (currently has a 6% coupon discount) is what I used: https://www.amazon.com/gp/product/B01I28TSCW

 

[Hacra]

While i am waiting for my new tires to arrive few good points have been made, i think i will give @J_C OBD2 scanner suggestion a go and further plummet into financial suicide as i ordered OBD2 dongles from ebay (some 5$ each), one was with bluetooth and one with usb cable so i can connect it to computer (laptop), which i will hopefully later use to make horrid mess of the oem cpu as i change few things...

 

[CDW6212R]

Untrue! A month ago I had my front left sensor go bad on my '98 4WD. "Maybe" it just needed cleaned off, but since it broke apart trying to remove it (carefully too!) it didn't matter, a new sensor was needed.

Forscan app plus an OBDII dongle can read the ABS sensor data to see if one, and which one, is having a problem.

Maybe my hub is going out, I made a topic asking about that, but so far it makes no noise, has no play, spins normally, and replacing the ABS sensor resolved my issue which was ABS activation around 5MPH slowing to a stop. Granted I've only put 100 miles or so on it since that repair but it was activating every 5th stop or so which has completely gone away.

The hub-sensor interface is a bad design with the only o-ring down 2/3rds of the way on the sensor shaft and no gasket at the top so water can get down in there and rust away the hole. I put some silicone grease on the new one to slow that down if not stop the rust.

Anyone who deals with rust on their vehicle in general, there is a high chance that trying to remove the sensor will break it. I would not pull them to clean them until you have Forscan app data about which one it is, otherwise I would have replacement sensors handy so you're not messing around with taking it all apart again to put a new sensor in, or leaving it disassembled waiting on one through the mail (local auto parts store prices are outrageous for those sensors considering what they are)... they only cost $10/ea ($20 for a 2 pack) on Amazon.

The Forscan idea is very good and that should be a common tool for us all very soon.

I did remove the one front ABS sensor that one time without damaging it, but I remember how fragile it was, and could easily see them breaking often if removed. I appreciated them being easier to unplug and leave in with a hub, since doing my sisters newer Jeep and breaking both of those front ABS sensors. On those, they are also fragile, but worse they are pinched in by the brake dust plate, and unplugging the wires seemed much harder. In hindsight I'd also figure out how to unplug those, they had small plastic tips which are very easy to break removing from the hub.

 

[Hacra]

Okay. Update: New tires are installed and drive feel is WAY better and it would SEEM most of the wobble is gone, hard to say still since we just had snow storm and the roads aren't exactly straight with all the snow, but it would seem the car doesn't pull to right anymore and it feels weird to let go of wheel and thing actually goes straight.

As i went to tire shop i asked the worked if they see anything special with the old tires and they certainly did, one tire at least had bulge in it and as they removed the tires he said the tires nearly crumbled from the rims...



If you click the image bigger you can see the bulge on top.

 

[shucker1]

Glad you got it fixed.

Classic Slipped belt symptoms is what you described in one of your first posts.

Anytime you see that steering wheel wobble on it's own from side to side and low speed I would look at tires first.

 

[CDW6212R]

Okay. Update: New tires are installed and drive feel is WAY better and it would SEEM most of the wobble is gone, hard to say still since we just had snow storm and the roads aren't exactly straight with all the snow, but it would seem the car doesn't pull to right anymore and it feels weird to let go of wheel and thing actually goes straight.

As i went to tire shop i asked the worked if they see anything special with the old tires and they certainly did, one tire at least had bulge in it and as they removed the tires he said the tires nearly crumbled from the rims...



If you click the image bigger you can see the bulge on top.

Great, that should do it.

What tires are those? They look a lot like the kind I got last Winter to replace my old set.

 

[Hacra]

Those tires in picture, i cannot remember. But the new ones are 235/75R15 Farroad Saferic.

Cheapest chinese tires i could find

262,72€ set with delivery from Estonia to Finland.

Edit: They seem to grip better than the 11 year olds, which is good enough for me.

Edit2: I will still go through replacing the other wheel hub and diagnosing the ABS sensors as soon as the OBD dongles arrive (ebay orders take forever).

 

[Mbrooks420]

Damn those tires looked beat. Look almost like an Altimax.