VolvoDeger First of all don’t be mislead as the haldex pump only operates when front wheels slip, so no need to undo plugs at module. It is most likely the auto causing this judder that comes in at times also it can happen at cruising 60-80 kph. Is your awd system working correctly? but confident it being auto.
Its been bugging me for ages. I have asked the auto transmission guys (Hutt Automatics) over and over again and they keep telling me there's nothing wrong with the transmission. "It's drive line" they keep telling me. The judder is always around 1400rpm but is there all the way up to 2000rpm - just more noticeable around the 1500rpm mark - and especially noticeable in 2nd or 3rd gear when I go up my street.
When the car was on axle stands, all 4 wheels were spinning. When I tried increasing the revs, I got up to about 1400rpm and then a red warning light came on and the engine seemed to automatically drop to about 1000rpm. I assume this is normal?
A few months back I had the diff bearings replaced. When the mechanic put the car back together, the back wheels were engaging (scrubbing rather than slipping) when I was reversing the car out of the garage or going around tight roundabouts. I took the car back.. $600 later they'd replaced a filter in the Haldex and couldn't actually explain why it was doing what it was doing but it seemed to "put itself right".
So.. is AWD working correctly? I have absolutely no idea. That's why I'd like to try and remove it from the equation completely.
The problem with this car is that I've had so many things wrong with it since I bought it. The auto transmission had a new valve housing which got rid of an awful gear change judder that I had between changing from 2nd to 3rd but the judder I have now is constantly there in all gears. At higher speeds it feels like a wheel balance problem - but its most violent at slower speed - 30kmph/1400rpm going up hill in 2nd gear.
Common sense would suggest to me that if they car used to change violently between 2nd and 3rd gear.. then maybe something became worn or damaged with this behaviour - something linking the transmission to the engine. But.. I'm no mechanic.
It doesn't help that there's only 1 set of automatic transmission "experts" in Wellington either. Honestly, I wish I knew somewhere local that had a clue what they were doing. Even the Volvo dealers use Hutt Automatics so that doesn't help.