Jacking

[XJSDriver]

Can anyone confirm what wheels are locked when automatic gearbox in park?

I need to sort out my rear parking brake shoes (no surprise there!) and am interested in what happens when you jack up one wheel, especially when your parking brake is useless. I have put wheel chocks on the other 3 wheels but am interested to know if the car could move without them as my car is on a sloping drive.

On older land rovers and the like which use a transmission brake, I understand that if you jack up one wheel the transmission can then rotate allowing the car to move with disastrous consequences if you are on a slope!

In the case of my Xc90 with a useless parking brake, are all wheels locked if the haldex is working, but if you jack up any wheel, that axle pair can then move due to the differential, but being a 4x4 the other axle with both wheels on the ground remains locked and so the car cannot move, if that makes sense?

[SwissXC90]

You should always chock when jacking on a hill, even if the transmission in P locks the drive train.
Chock all wheels on the ground and you will have no problem.

[okedave]

I live on a slope too. I started to jack up my front drivers side, but the moment the wheel left the ground the car moved and forced the jack over gouging a little hole in the road surface. So yeah I would definitely use something physical to stop it moving. Ive now bought a set of ramps which are perfect so long as you dont want to take a wheel off, lol.

On a side note its also made me wonder what would happen if I get a puncture and need to change the tyre, I no longer have confidence that the car will stay in place when I jack it up :-(

[oragex]

I would be afraid to jack in on a light slope. As for the parking brake, I never pull it when jacking because it may force on the shoes - I did so once the and the shoes made a weird noise. These are known to delaminate now and then.

[aland]

The XC is effectively FWD until the Haldex engages the rears.
With the ignition off, the Haldex is not engaged, hence one of the AWD tests is to see if you can spin the propshaft - the rear will always spin when not engaged, and the front will only spin if the splines are damaged.

If you are jacking the rear, and the fronts remain on the ground, it won't move.
I'd suggest chocks on each front and only jack as much as needed at the back to lift the wheel and get an axle stand under.

Based on my recent park-brake fun with my XC, your shoes are probably fine, but fit the manual adjusters available from Volvo or ebay and adjust through a bolt-hole until just binding, then back off.
You'll need to slacken off the cable in the passenger (yes passenger!) footwell first. Afterwards I needed to adjust a little to take the slack up.

In my case both the rear plates were in a bad way and one of the shoe retaining lugs had rusted away, I needed to replace both plates. My car's previous owner lived by the sea, and I suspect towed a boat and backed it down a slipway into the sea - I have more rust under the rear-end than average

[Tannaton]

Its all been said but to summarise:

- Even though the car has AWD you cannot use it to "lock" the rear wheels stationary.

- In Park (P) the transmission is locked and consequently whilst both front wheels remain firmly on the ground, they will be locked, via the transmission through the differential. If one wheel is raised or loses traction, the car could move.

Hence I would suggest you jack the car via the tow bar bracket or middle of the rear subframe so both rears are lifted simultaneously and all the weight is evenly on both fronts. Then the usual chocks and axle stands, and take car not to have feet or arms under the car.

When checking over your parking brake, as has been said the adjusters are a very good addition, but remember also to use genuine Volvo shoes and check both inner surfaces on the drum part of the discs for corrosion. Where there has been corrosion which has been removed by applying the brakes - this leaves a rust coating which is hard than steel and has less friction, in these cases its usually new discs needed.

(Note - I expect some people will have views on jacking the rear of the car by the tow bar or middle of the subframe but I've been doing that (carefully, with wooden blocks) on XC90's for years with no ill effects so have no hesitation in suggesting it).

[XJSDriver]

Thanks all for you help - I have just received the adjusters so plan to fit this w/e and will be using the chocks! I did remove one of the drums last w/e and as [aland] suspects the park brake shoes are fine, lots of dust though and some corrosion but I will try the adjusters and will plan a complete refurb later in the year if this works.

[okedave] - I too am now concerned about jacking if tyre flat so will purchase some spare chocks and keep them in the back off the car; even if this fix works and I end up with a brilliant hand brake I will never trust it with my life!

Watch this space!

[XJSDriver]

Fitted the adjusters this w/e - discovered the left hand side disc was corroded inside so sanded with a dremel, will do for now and will plan for new discs later in the year when I had some more wear out of the pads.

The good news is that the adjusters have worked a treat - taken up the slack in the cable so now locks wheels at 4 or 5 clicks. Still not the easiest parking brake in the world to use but does the job and holds easily on a steep hill
Cannot recommend these enough.

[Tannaton]

Originally Posted by XJSDriver

Fitted the adjusters this w/e - discovered the left hand side disc was corroded inside so sanded with a dremel, will do for now and will plan for new discs later in the year when I had some more wear out of the pads.

The good news is that the adjusters have worked a treat - taken up the slack in the cable so now locks wheels at 4 or 5 clicks. Still not the easiest parking brake in the world to use but does the job and holds easily on a steep hill
Cannot recommend these enough.

The disc will probably be fine now you have dremel'd it - I know it's not good practice for brakes but it only has to lock the wheel - not slow the car down progressively...

[aland]

Originally Posted by XJSDriver

The good news is that the adjusters have worked a treat - taken up the slack in the cable so now locks wheels at 4 or 5 clicks.

That is my experience also on both my XC90 and V70 - park brake MUCH better since fitting those, and quick to fit.