While pulling over a mtn pass this evening, during a snow storm at temps at 36F, our xc70 started to clunk and make a grinding sound. Shifted into neutral and adjusted fan speed and temp but nothing changed the sound. Coasted for 2 miles down hill and it went away. Ran great after that. Turned around 3 hrs later and went back over the pass and same thing happened as we crested the pass again. Not a high mtn pass as the pull is from 1500ft to 3300ft.

Any ideas on what is up?> Sounded like a u-joint clunking and a flywheel grinding?

Thanks,

 

Hi, welcome to the forum.

This was caused by the Graham Mtn. Gremlins. They have been causing these problems since Pioneer days. Their pranks are usually harmless and can be totally eliminated by installing a Cow catcher to the front of your vehicle.

But, it also could have been caused bythe drive shaft going to your rear wheels.Giving that it wasn't a permanent problem it is hard to tell exactly.

Check this recent thread out, it sounds simular: https://volvoforums.com/m_82618/tm.htm




.