Growling sound while driving 2006 xc70 Topic is solved

Rvolvos · Post by **Rvolvos** » 03 Oct 2021, 16:13

Trying to find the source of the growling sound while driving.
Removed the front brakes from the car to better diagnose the front wheel bearings. Car in neutral , while rotating the driveshaft by hand It felt gritty.
After disassembling the rh spindle the wheel bearing felt good. Removed the driveshaft and checked the carrier bearing, it felt great.
Disassembled the lh wheel spindle, bearing felt great.
When I rotate the driver side driveshaft by hand the differential makes a loud rattling sound and it does not feel smooth. Is this normal?

Also it looks like the front bearing of the awd driveshaft is worn. It moves up and down and clicks loud. Could this be the source too?
Thanks

Post by **Blacklab467** » 03 Oct 2021, 20:05

Sounds like the angle gear is coming apart!

Rvolvos · Post by **Rvolvos** » 03 Oct 2021, 20:18

Crossed my mind, but the awd driveshaft was not spinning while rotating the driver side axle.

Post by **Blacklab467** » 03 Oct 2021, 21:23

Jack the car up, put the key in #2 position and put the car in drive. If you can spin the propshaft independent of the front wheels, the angle gear or output shaft/ collar sleeve is done. If theres play in the output shaft bearing or fluid leakage in the angle gear, its probably done or needs major overhaul consisting of mainly bearing change.

Post by **RickHaleParker** » 03 Oct 2021, 23:10

Is the brake pad retaining spring intact?

A broken spring was the source of a grinding noise on my C70. Let the brake pads ride on the rotor.

See #3.

Rvolvos · Post by **Rvolvos** » 04 Oct 2021, 10:57

Thanks much for the input.
@Blacklab467 I have tested the AWD system on 4 jacks last week with the engine running. It worked great with traction control on and off.
@ RickHaleParker, yes the springs where in place, verified when removing the brake calipers.

I will remove/ disconnect the drive shaft at the angle gear to better pinpoint whether the angle gear or front bearing of the driveshaft is the culprit.

motormikeyman · Post by **motormikeyman** » 05 Oct 2021, 14:15

You can check the wheel bearings by driving the car and turning the steering wheel side to side. If the growl is louder when swerving right, then it is the left wheel bearing, etc. My wheel bearings "felt good" too until I completely removed them and even then they did not feel too bad. Different story when the weight of the car is on them.

ans713 · Post by **ans713** » 05 Oct 2021, 15:09

This is my first posting on this forum. I am "no" car expert so I have been doing lots of reading on this forum and watching U tube videos.

When I read your posting, I was reminded of a U Tube video I was watching when I did a search on "CV Axels".

The video was on "South Main Auto Repair LLB" "Clicking CV Axel Joint, What makes it Click".

The front end of the car was making lots of noise while driving at low speeds. Reminded me of what you were describing.

I did not know anything about "CV Axels" and did not understand why people were making a fuss over them until I saw the video.

A very messy job if one had to repack the grease. Sure glad I was just watching and not doing.

Rvolvos · Post by **Rvolvos** » 26 Nov 2021, 21:46

Can anyone recommend a good drill bit for drilling out a Downpipe bolt?

Tried the Bosch drill bits with 8% cobalt, they work for about 10 seconds.
Spend 1.5 hours and have made a 5mm deep hole.

Update on the progress; I replaced the front cv joint of the prop shaft with a Pro Sweden part, it was loosing grease after the first test ride to work and had the same amount of radial play after the short use. Ordered a Dorman replacement part and it arrived with a broken cork gasket.

Quality did not look great either.
Started to disassemble the prop shaft for the 2nd time and one of the Down pipe bolt was completely seized after 3 weeks of hardly driving the car. I managed to get 10mm out by moving it back and forth but broke of in the end. It’s the one bolt on top fully threaded through the flange. It I can drill it out I should be able to replace it with a bolt and nut.

Post by **Blacklab467** » 26 Nov 2021, 22:42

You should'nt need to drop the downpipes to remove the propshaft or the angle gear. It's easier to remove the exhaust pipe and muffler rubber hangers and slide to exhaust to the left (driver's) side to access the propshaft and carrier bearing.
BTW; check your heat shields along the length of the exhaust, I've come across 3 cars now that have produced a hard to find growling noise that turned out to be a heat shield rubbing against the propshaft, one guy changed his wheel bearings and CV axles trying to eliminate the noise.