Volvo diagnostic tool I use:
Car model and year:
2005 Volvo
XC70
Car issue:
Got strange wheels slipping today when pulled
hard from the stop. No blinking traction icon. A loud clank coming from rear
end when I slowly turn with steering wheel at utmost position, sounds like ABS
or, perhaps, it is ABS. Roads in MA are currently covered by usual crap left
after snow has finally melted.
This is what I saw in a test drive with
DiCE/VIDA attached to the car:
In neutral:
In drive, pulling from the stop, not very
hard:
In R, backing up the hill:
I see nothing criminal. Oil pressure sensor
shows linear reaction to AWD demand, does not look like stuck sensor, which
jumps from idle pressure to purge valve release pressure.
Also there's inactive DEM-0006, which has
happened at 204900 km, car has now 2062000 km (128113 mi). According to my
notes, at the time of this error registered the car had other electrical
gremlins, including no starts.
Pulled the DEM plugs, blown with compressed
air. Plugs were clean, no signs of oxidation.
Other info on the car: when I bought it in
November 2012, it had 80k miles on the clock, dealer serviced. I did stage 0
and, among other things, replaced AOC filter and oil. Both were clean, apparently
recently changed. Angle gear had signs of removal, I bet collar sleeve was
replaced. AWD was working in this winter, car plowed really well. 2 or 3 weeks
ago I called it a season and swapped winter tires Generals Alitmax Arctic
(licensed Gislaved Nordfrost) with all-season BFGoodrich Advantage T/A, which
still had 3 mm (1/8") of thread left before tires call for a replacement.
Of course I felt immediately how crappy is the traction on these tires after
Generals/Gislaved (Swedes know how to make winter tires). On a rainy day car
was banging at the rear in the every turn in a flooded multilevel garage, but
that is exactly what I also have heard from the Audi with Torsen AWD in front
of me (ABS was engaging).
So what do you guys think I'm looking at? Unsatisfactory
worn out tires, which easily loose traction and make ABS upset, or is it the
first sign of Haldex heading to Valhalla? I could not replicate torque steer
and front wheels spinning on a hard pull, which are easily achievable on wife's
FWD V70 with same model BFGoodrich tires.
I solve some problem as following shows:
it was Haldex pump. Replaced, and the rear
axle does not feel like living its own life now.
Oil screen on my pump was not that bad... Oil
had some clutch material dispersed in it, but still was green, uniform and of
about right viscosity.
The job is tough, but not that bad. Probably
it is 10x times easier on Gen 4 Haldex, where driveshaft flange does not cover
the pump, so no need to drop exhaust and driveshaft for the replacement.
I bought 3 pullers in order to remove the
flange on AOC side. The one which worked was actually Craftsman steering wheel
puller found at Sears. Two jaw-type pullers didn't work at all.
The dealer managed to damage the main seal
when oil was changed (before I bought the car - I know that work was done, and
done by the dealer), so it was very slowly dripping through the flange. Lowest
bolt was noticeably wet after sitting through the night.
It seems the main reason of failed AOC
function was low oil level - didn't check it in two years since the last
oil+filter replacement, and not before starting the job, but when I finally got
the pump out I've collected way less oil than 0.5 liter I put back at the end.
Anyway, after spending slightly over than a day under the car to get to that
seal and the pump and the filter, I didn't want to do it one more time when
10-yo pump will finish its brushes or if it is in fact broken.
Though that could be an advise for other XC70
owners: check oil level if AWD started to misbehave, plus you see traces of oil
on the flange or anywhere on Haldex unit. At least, if it turns out that the
seal replacement didn't fix the leak, I'll be just topping up AOC with oil once
a year or so
