2000 V70R - Now it begins -Rear AWD sub-frame replacement

[scot850]

Well, it is spring, and so I could no longer put it off. The rear AWD sub-frame on this car has to come out. All I can say so far, is in typical Volvo design philosophy, if you can find something to bolt to something else, then go for it, and make any easy job twice as difficult. This 'R' is proving to be an even bigger PITA than the 98 V70XC due to unique levels of stupidity. Unique rear caliper mounts that need a special shorty 7mm socket to get in to loosen the 2 slider bolts as it is positioned too close to the rear coil springs for example.

2 of the rear prop-shaft bolts had been damaged by PO or possibly when the prop-shaft was replaced a few years ago. Also the 'R' prop-shaft is counter-sunk into the flange at the front of the viscous coupling unit and had to be persuaded out with a cold chisel and 2 lb hammer. I plan to weigh the prop-bolts as Volvo claim they are all specially weighted to see if it is true!

Next I had planned to remove the VC unit, but discovered that one of the 4 VC unit housing to rear diff bolts is totally in-accessible on this car. Larger muffler and a different shape of fuel tank to the XC. I had planned to leave the tank in place, but it now looks like I have little choice but remove it as there is no way to support the 2 halves of the tank as per Volvo instructions, as the VC housing can't then drop down with the rest of the sub-frame. I may get away with carefully supporting both halves of the tank independently.

Hoped also to leave the muffler system again in place, but had to remove it to allow the sub-frame to be remove as Volvo have attached the muffler mounts (twin outlets on this 'R') on both sides to the frame and made their mounting brackets in-accessible without removing it first.

Last hitch for today is the 2 ABS sensors are totally seized into the rear hubs and I had to cut the cables to remove the frame.

As Matthew once said to me, " Volvos - the reason for why we love to hate!'

Tomorrow, I hope to get the other half of the muffler off and figure out the best way to support the fuel tank to allow the sub-frame to be dropped.

Any suggestions on how to support the rear of the car to allow the front axle stays to be unbolted as Volvo designers in their wisdom bolted the mounting under the rear jacking supports?

Oh, roll on tomorrow.......!

Neil.

[sanfelice]

yyyyyyyyyikes. I hope that I don't have to do that to my VR anytime soon (my VC was replaced by the original owner in something like 2005).

Do you have lots of salt on the roads where you are? We do here, and this is why I try to wash the undercarriage as much as possible during winter months.

[scot850]

Yes we get a lot of salt on the roads, but the real killer is the 'de-icer' they have been using for the last 4-5 years. That is liquid rust and very aggressive. To date I seem to be the only person that has highlighted the issue, so maybe it is unique local conditions, or a lot of owners not looking closely at their cars. I washed my car regularly, but it didn't help. My advice would be to keep an eye on the sub-frame at the rear of the rear wheel arch. If the metal on the inner arch starts to rust, clean it off ASAP and re-paint. This may help to delay any issues.

Neil.

[scot850]

Quick update from 2nd visit to the challenge.

Removed rear anti-sway bar. Was totally unable to remove the LH rear muffler and pipe as rusted together. If I can manage to remove the axle without disturbing it then I will leave alone.

Removes the LH rear brake assembly, but left both calipers attached to the flexi-pipes for now and tied up using wire over the rear jacking mounts to support.

Decided to try and work on loosening the rear sub-frame bolts. I was having nightmares about this, and this is the case where you wish you were wrong. I have an electric torque hammer and used that to easily remove the 2 hub nuts. This can apply up to 350 ft/lb torque. This couldn't even move the front and rear of the 3 bolts on the LH side. The dumb idiots at Volvo have fitted steel bolts through the aluminum frame without using a steel sleeve or washer under the bolt head. The bolts have completely reacted with the frame and welded themselves to each other. All I achieved was to shear the front bolt about 0.5" from the head using a 3ft breaker bar. I've decided if I can't remove the bolts, I will grind the heads off the bolts, and then hammer the frame off the remaining 'studs'. I'm hoping that with a little luck, the remaining stud will when not being stuck to the frame may be able to be turned out with a large pipe wrench. The remaining one that has sheared, I'll have to grind flat and then try to drill and re-tap the thread.

Tomorrow, I also will have another go at removing the VC housing. I'll try to remove the bolt that supports the front of the housing and see if it will allow the housing to rotate enough to allow access to the one in-accessible bolt holding the housing to the diff. If time allows I will also make wooden supports for the 2 halves of the fuel tank and then ready for trying to drop the rear frame if I can get it loose. I'll update once I have made more progress.

Oh, and out of curiosity, I decided to test the belief that Volvo used different bolt lengths (and therefore weights of the bolts) for the prop-shaft to balance it. In my case, they all measured 48.1mm in length (including the head), and all 6 weighed in at 20gms each. Doesn't mean it isn't true, but in the case of my car and the rear prop-shaft bolts, the myth is a bust!!

Neil.

[Blockpartie]

Are the propshaft bolts colour coded?
When yes, your propshaft has been replaced and the service solution was used upon install.
If not someone messed with it before.

You will have loads more fun with the "steel bolts in aluminium"-issue, especially with fuel system components.
Also don't damage your brake components, absolutely nothing is available anymore. Not even discs.

[scot850]

Thanks for the support! Actually, as to the there are no brake parts available, I recently bought a set of genuine Volvo rear brake rotors from a dealer and also the parking brake cables, and all the parking brake hardware and parking brake shoes. I next need to try to find the rubber sleeves for the rear caliper sliders as they are worn.

As you rightly say, the prop-shaft was replaces at some point (I have the service history) and all the bolts will be the shortest (the length I gave was for the overall length, thread length will be nearer 40mm which is the shortest option listed). As an engineer, I still have difficulty believing the different bolt lengths and weights would make any noticeable difference to balance on such a small diameter. The balance weights on the VC similarly.

Neil.

[misha]

...As Matthew once said to me, " Volvos - the reason for why we love to hate!'...

Hm.....i guess that you never worked on big Citroens with hydropneumatic suspension. :mrgreen:

That is real art. :mrgreen:

Working on Volvos is nothing in comparison with them. :wink:

[Blockpartie]

Thanks for the support! Actually, as to the there are no brake parts available, I recently bought a set of genuine Volvo rear brake rotors from a dealer and also the parking brake cables, and all the parking brake hardware and parking brake shoes. I next need to try to find the rubber sleeves for the rear caliper sliders as they are worn.

Notice how I wrote "brakes" not "handbrake"...

Which rotors? (parts number please)
The '00 R AWD vented discs are no longer available. Everything you can get is NOS from a dealer, Volvo has none left in their warehouses.
Calipers haven't been available for the '00 R AWD for some time, only the guides/mounts. For the pre '00 AWD brake you can get calipers but not the mounts. Which is a problem as Volvo has advised dealers to downgrade the '00 specific brake should it require repair. Sadly the sliders wear out, bind and wreck the mount.

Handbrake parts are no problem with the exception of the clip securing the handbrake cable. That is sold out nearly everywhere. (There is an Ebay listing claiming to have it - price is 3x list price)
I bet that your clip is rusted to pieces.

Replacement prop shafts were different from production line prop shafts. Think of the bolts like wheel weights, just a few gramms can make the difference between a smooth ride at highway speeds or some shuddering.


Misha:
You clearly have never worked on an early AWD Volvo.

[scot850]

Thanks guys for inputs.

Yup, rear rotors are vented. Bought from Tasca who brought them in from Volvo warehouse. Local dealer also showed them as available, eEuroparts also listed OE as available. There is also a couple of aftermarket options also.

2000 V70R rear vented rotor

2000 V70R rear rotor part number

2000 V70R rear brake pads

The only parts I want to replace are the slider pins and the rubber bushes they sit in. Calipers as you say will be an issue when they need to be replaced. Hopefully a rebuild kit would suffice.

As to the cable clip for the parking brake, mine are rusty, but useable. Also, when in PnP if there are any AWD P80's I always try to pull the clips if useable. It is a real pain that Volvo don't make another batch of such a simple part, that could effectively right off a car. Or even an FCP or IPD or someone like that.

I did once work on early Citroen maybe 30+ years ago when I helped out in a local garage in Scotland where I grew up. They were a pain (ever try to change the spark plugs on a GS motor?!). Other cars that were challenging were early Minis with hydrolastic suspension, Reliant Scimitar heater pipes that can only be felt not seen to replace. All brand have their challenges in areas. Volvo P80/850 AWD manage to be a pain in every area. The Volvo rule of design, 'For every 3 bolts you use, make sure 1 is totally in-accessible without having to dismantle half a car'. Rule 2: ' If you can find a bolt that is easy to access, mount another bracket on it or item that requires half a car to dismantle first'.

I am procrastinating again, so off for a quick lunch and then attack the car with a vengeance again!

Neil.

[scot850]

After over 2 hours, all I managed to achieve was to remove the VC unit. With the benefit of hind-site and not taking the Volvo instructions too literally, I suggest the following is the way to remove it:

1) Leave the Prop-shaft connected, but the bolts loosened, and undo the VC to diff bolts first. Again one was kindly left rounded. Took nearly 1 hour to get the 6 bolts out! Life would be easier with a hoist!
Remove the prop-shaft to VC flange bolts. M ark all the positions of the bolts in case they are different and ensure you have a fixed point of reference on both flanges. I used a punch to mark both

2) Remove the front bushing bolt for the VC casing allowing the casing to drop down at the front. Then using a short 3/8" drive 14mm socket and lots of extensions and a wobbly extension by the socket, align the ratchet and extensions so they just clear the back of the front VC flange. Undo and remove the 2 top bolts.

3) Support the VC casing, and loosen the 2 lower casing to diff bolts but don't remove. You may need use a piece of wood and a hammer to break the joint. I used a trolley jack to lift the unit slightly and then it separated. Remove the lower 2 bolts and it is out!

Tomorrow I will try again to loosen the RH sub-frame bolts.

Question: If anyone has removed a AWD rear sub-frame, is it possible to do so without dropping the fuel tank or does it all have to come out?

Thanks for reading.

Neil.