Right rear under car clanging noise Topic is solved

[jonesg]

You can drop the exh and let it rest on a milk crate, don't damage the flex pipe, it doesn't flex too much.

[leapdragon]

@jonesg, that's an important tip, thanks for that.

@Pete, after doing some more research, I'm going to have to get it up and get under it again tomorrow and see if I can figure out which end (or middle) has the problem.

Angle today was slightly bad to get to the shaft middle with my hand. I was grabbing it near the haldex and rotating either way but what I didn't like was the sounds I was hearing as I did it from somewhere farther up the shaft. I would expect no noise, but there was some muffled pinging noise, like ball bearings were grabbing somewhere and then letting go and it was ringing up and down the shaft.

Did check all the drive shafts on the wheels, everything quiet and tight, all the boots still sealed. Re: diff, my impression is that everything is pretty clean under there, but I'll look more closely tomorrow. Wheel bearings were last checked when I rotated tires just a couple weeks ago and were good then, so hopefully they're still good.

From what I gather YouTubing tonight, there's the carrier bearing in the middle of the drive shaft, a U-joint near it, and then a CV joint at the head. It sounds a bit fiddly to rebuild all of these vs. just dropping in a whole different shaft if I can find one. I don't want to pay the $1200+ for OEM but maybe there's a low mileage one somewhere in town in good shape...

[- Pete -]

If your carrier bearing is still intact, I’d suggest just replacing the CV joints, but only if they are bad. The rear one (which sits inside the flange just before the Haldex/AOC unit, which sits just in front of the rear final drive), doesn’t usually go bad, the front one goes bad more frequently due to the heat from the downpipe cooking the rubber boot & it then cracking & releasing all the lube.

My suggestion is to continue looking for the sole cause, if there is just one, vs doing the parts-shotgun approach. The CV joints can be had through a company called “Colorado Driveshaft”. They use high high quality CV parts made in Poland and I believe Turkey. This is one job you want to use the highest quality parts for. Volvo CV’s are ungodly expensive, the Colorado Driveshaft are easily of equal quality, at far less coin.

If your carrier bearing is bad you can also buy an entire rebuilt driveshaft from them as welll. I did this recently for one of my AWD P2’s & came in around $600, once I got my core charge refunded. Do NOT buy an inexpensive aftermarket driveshaft. You will most certainly regret it.

As far as driveshaft removal goes, it’s not a quick job, but is very straight forward. If you have a decent selection of tools and some physical ability (and patience) it’s far from intimidating.

If you end up needing to remove the driveshaft, I would also suggest you purchase the special AOC oil and a new, updated filter. The only way you are able to replace this is to first remove the driveshaft and flange on the front of the AOC. If yours has never been done, it is surely due. The service interval calls for 20-30k AOC oil changes, but Volvo tells customers otherwise. Basically once your DEM pump fails, then change out everything at once. Just silly.

[darylrobert]

My driveshaft pings sometimes between gear shifts as i replaced the rear universal (volvo say not to do this) it has some fore and aft play. (gluing the universal would fix this?maybe)..its possible to unbolt and remove drive shaft but the exhaust needed to be lowered or exhaust brackets removed if my memory serves me. People say not to let the exhaust hang but i let the middle section hang a number of times (not the full length of exhaust) and no damage was done. Once unbolted it appeared to be stuck so a tap with a hammer and some brute force and swear words is needed to wrestle it free.

[leapdragon]

Hi all, update:

Got a low mileage prop shaft locally from a salvage yard and put it in today. Noise is gone.

Well, at first there was a new noise. Turns out that over the same 200k miles that caused my center support bearing to sag to almost nothing, the shielding had also sagged something like 2cm and as a result the U-joint in the replacement shaft was rubbing on it.

Some artful bending and all was well.

Having never done this before, wasn't quite sure what to expect, but apart from one thing, the job is relatively easy.

0. Put the rear wheels on ramps and right front wheel on a jack stand (i.e. off the ground), block the left front wheel
1. Undo the two bolts in the middle of the exhaust line and split it
2. Remove the plates under the exhaust line, undo the bolts holding the center support bearing to middle plate
3. Undo the exhaust line hangers, drag the main part of the exhaust line away
4. Loosen the first three hex bolts on both ends of the prop shaft
5. Put car in neutral climb underneath, and rotate passenger side wheel to reveal next 3 bolts
6. Put the car back in park to engage the pawl (so that you can apply force w/o rotating)
7. Loosen the next three hex bolts from both ends and remove them
8. Car back in neutral, rotate again to reveal first three bolts
9. Remove the rest of the hex bolts from both ends
10. Fight like hell for a couple hours to get the prop shaft to pop free of the Haldex flange
11. All the same stuff in reverse order

For anyone planning on doing this, I strongly recommend having the following on hand:

- Some spray rust penetrator (that exhaust ain't comping apart otherwise)
- 11mm extraction socket (that exhaust ain't coming apart otherwise)
- 9mm allen socket (my 2007 wasn't 6mm like some apparently are)
- 10+ inch ratchet extension and U-joint
- 10mm nut wrench

I don't know if I'd have survived this doing it with a standard 9mm allen wrench in the "L" shape. At the very least it would have been a huge pain.

Also of note, getting the prop shaft to come loose from the Haldex flange is not so amazingly fun. There are threaded holes on the back but there's not a lot of clearance. In the end I found that the one thing I could get in there were the two bolts that normally hold the center support bearing to the center shield. They were a little bit too short, so I ended up sticking ~1cm long x 5mm diameter brass pins in the holes to give some added reach. Even then, the amount of force I had to apply from the rear to those bolts to get it to finally pop free was really something. There are two holes on opposite sides of the rear of the flange that are offset 180 degrees from each other and apparently to enable you to pop it free, but I had to use both and pull like hell on each side, rotating between pulls, before it finally popped out after a couple hours of fighting it.

In any case... noise gone. Hopefully this prop shaft goes another 200k.

[leapdragon]

@Pete thanks for the tip on servicing the works. Didn't do it today due to time but I'm going to rip it all apart again and take care of that in a couple weeks. I presume the prop shaft won't have locked itself as badly into the flange by then so it should be pretty quick, getting everything apart is really ~30 mins apart from that task.

[- Pete -]

Nice work! There are several areas on these (AWD, especially) P2’s that will make you feel like more (and sometimes less ) of a man. That rear driveshaft CV joint is definitely one of them the first time you go after it. I applaud you for going in blind and coming out triumphant!
Yes - the non-threaded holes are key in this exercise, as you figured out. Also, I like your technique of keeping one front wheel off the ground & using “park” to tighten the Allen screws. I’ve always done this on a lift & therefore needed to use a counter hold or just shoot them in with an impact. I really and usually hate and avoid using an impact on Allen screws, but the factory screws really do hold up quite well.

I always put a little low temp/strength thread locker on those 6/12 screws. If the front ones back out, the little boomerang washers swing around & cut through your power steering high psi line (no bueno).

One other thing I do is coat the flange and head of the CV with grease for ease of future removal.

So correct me if I’m wrong, but it sounds like your original driveshaft may not be entirely bad then. If the carrier bearing support/shield had just sagged & was the reason the driveshaft was contacting the exhaust, I’d certainly keep the original around for a spare.
You never know…