I experienced this after offroading not too long ago.
It turned out to be the exhaust bracket being pushed up causing the exhaust to grind against the drive shaft.
The result: Loud high pitch metallic grinding noise from underneath the XC.

Here's the official TBS:
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Issued for R vehicles but goes for all P2X AWD models. Dated Januari 2004.

Description,

There have been reports about the FACT that S60R and V70R vehicles can be damaged at the under side of the vehicle when driving over speed bumps. This is caused by a bracket (P/N 30647428) (See attachment) which is mounted under the vehicle. The bracket is only used for production purpose to keep the exhaust system in place and serves no other function.

Because of the lower ride height of the R vehicles the bracket can touch the ground in extreme situations. When the bracket touches the ground it can bend (See attachment image) and subsequently damage the exhaust system and the drive shaft (cardan).

Product changes,

Investigating if product can be changed in production.

Part return,

No

Technical report,

No

Service,

Volvo advises to remove the bracket when present on R vehicles during service. This to prevent future damage.

Remark,



These brackets are present under all P2X AWD vehicles. If there is a concern for problems the bracket can be removed without consequences.
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And here&#39;s my bracket