Axle ping/click and ABS light, 1996 850

eleaf · Post by **eleaf** » 23 Jun 2018, 14:53

Aloha,
I had the driver's side cv axle replaced. About a month later the ABS light came one (about every 8th start it doesn't come on, but usually comes on after driving a bit). I am also noticing what I believe to be 'axle ping', I hear a single click noise from the wheel whenever I let the clutch out going forward, and then a single click again if I go in reverse. It also makes the click if I accelerate and then let go of the gas (one click on acceleration and one click on decel). I can hear it whenever letting out the clutch shifting into gears 1-2 especially but not at higher speeds. I assume it is the axle has slop within the hub, but I couldn't find an anti-ping bolt for this model as it uses a large axle nut not a bolt. The axle bolt didn't 'look' loose.

I'm wondering if the axle ping noise and ABS are related at all and if I should be concerned about that axle noise??

Thanks!
1996 Volvo 850 GLT 5-speed manual

Ethan

Post by **abscate** » 23 Jun 2018, 16:11

You can read the codes and get info on the fault, but a loose axle nut or bolt will cause an ABS error.

Post by **theWIFES_S70** » 23 Jun 2018, 16:21

Hey Ethan,
I would keep an eye on the noise coming from the CV axle. If you replaced it, it might'be been replaced with an inferior part. (There has been documentation on here about "new" axles that were worse than the 20yr old parts they replaced...) Do you know what brand axle it was? I've had luck with Napa and Autozone axles.

The CV axle noise is perhaps the easiest noise to diagnose of any suspension noise on the P80: the tried and true creeeak-click-click-click. If it clicks during a right turn (it's the left axle) and vice versa. You can drive 1000s of miles with a click on a turn. It's the click when you're on the straightaway that's the one to be really worried about, that's when you're on borrowed time.

Before pulling the axle and replacing, I'd double-check that your mechanic tightened all control arm nuts and the ball joint nut, too. I'd also check the sway end link bolts, too. This car really needs to have all of those bolts torqued to spec I'm going to guess it's of those bolts. (Let's hope!)

As for the ABS light. Sometimes you can pull and stress the ABS wire when doing front-end work, e.g., replacing an axle... Make sure you don't have a small tear. Couldn't hurt to remove it and clean with electric parts cleaner before reinstalling.

Also, have you replaced or had your ABS module updated? If not, it could just be that your car has decided to "bless" you with a double-whammy... Our P80s are giving vehicles...

MDK · Post by **MDK** » 23 Jun 2018, 17:30

As far as your axle is concerned... the speed sensor is fitted directly above the front axles...may have a bad connection or the mechanic didn't clean the sensor. If the old boot was torn it may have thrown grease in there. A single 12 mm bolt holds it in place. Secondly, as far as the axle nut goes, it's a 36mm socket. Simply pop off the hub cap or center cap and make sure it's tight. You should be able to do this with out removing the wheel. MDK

eleaf · Post by **eleaf** » 23 Jun 2018, 18:59

Re: axle noise. I climbed under the car with the wheels turned on flat ground. I pulled on the control arms, end links etc and didn't find any movement, maybe just a tiny bit on the right sway end link (barely perceptible). I carefully pushed on the wheel to rock the car back and forth and I noticed a very slight noise, which I could 'feel' - it was coming from where the axle connects into the transmission and I could feel it with my hand on the axle arm. Felt like there is a slight slop where it connects to the transmission when rocking back and forth, but I read in another forum post this is normal? The axles are not volvo brand, one was from ipd and the other was ordered from an indy volvo mechanic both were replaced within past year or so. This happens on both right and left axles. I couldn't feel any movement where the axle connects to the wheel hub, only on the inner transmission side. I don't believe this is the noise I've been noticing. Pushing the car back and forth wasn't enough to reproduce the louder click.

The louder click/clunk noise I am referring to I can only reproduce whenever there is a larger shift in torque (releasing the clutch in a gear or going back and forth from forward to reverse). It is not the clickity clacking noise like a failing cv joint when turning, it's a single click when the direction of acceleration or torque changes slightly.

Otherwise, I am beginning to wonder if it could be a loose motor mount, the transmission torque mount, or subframe bushings? Best way to check for that kind of movement?

Front abs electrical lines appeared okay from what I could see with the wheel on.

Thanks guys.

Post by **scot850** » 24 Jun 2018, 02:06

Check the motor mounts like you suggested. Check the top torque mount bush for tears (the one fom the back middle of the engine bay to the firewall) also the lower torque mount bushes (middle front under car/engine) and particularly the smaller rear mount. Finally the engine mount under the crank pulley to sub-frame on RHS of engine. The rubber section separates fro, the lower metal pad.

Neil.

Post by **erikv11** » 24 Jun 2018, 09:58

This could definitely be a bad control arm bushing, where the control arm mounts to the subframe. What is the age/mileage on that part?

eleaf · Post by **eleaf** » 24 Jun 2018, 13:21

erikv11 wrote: ↑24 Jun 2018, 09:58 This could definitely be a bad control arm bushing, where the control arm mounts to the subframe. What is the age/mileage on that part?

The drivers side control arm was replaced about 10 months ago with a lemforder one due to a bad ball joint, so not too many miles on that one. Right hand hasn't been replaced for as long as I know, though the mechanic couldn't find any looseness in the suspension when they redid the cv a few months ago. Though maybe grabbing it doesn't generate enough leverage to notice movement compared to when engine torque is applied.

Post by **erikv11** » 24 Jun 2018, 14:00

Hopefully the mechanic knows to pre-load the control arm bushings before tightening the bolts to the subframe, as he likely dropped the control arm to do the axle job.

If it is a bad control arm bushing it will give the same click when you brake - any time the weight shifts forward or backward. So far you have only mentioned the click/ping under transmission load change, if does it with braking too I would (unfortunately) keep the control arm (and the engine mount(s)) as a possibility. If not under braking, seems you have zeroed in on the axle.

eleaf · Post by **eleaf** » 24 Jun 2018, 14:13

I attached photos of the mounts and such I could easily access. Looks like there is a tear in the top motor mount bushing (not torn all the way through though). On the transmission torque mount, it was harder to tell how the bushings are, the little one was covered in oil from a flame trap leak that was fixed. Also posted a pic of the lower hydraulic motor mount just behind the radiator.

It does make the noise if I accelerate in 2nd gear (one click) and then release the accelerator and after a second (another click). I'm actually not sure if it does it when braking though, will double check that...