2000 s70 n/a manual grinding noise

Veilleuxpbd · Post by **Veilleuxpbd** » 05 Oct 2015, 22:34

Hi all! I noticed that I hear a slight grinding noise that correlates with my rpms, but only when the car is in gear (M56 transmission) and independant of wheels turning. The noise kinda sounds like you were pulling a rake on pavement about once a second every 2ks the engine is turning, and is more noticable when accelerating hard, climbing a hill or when the engine is cold.
Is it a load-dependant part of the engine that is lacking oil (synthetic, changed 1500kms ago btw), the transmisson that is damaged (original transmission, original owner always did the services in time with a volvo dealer (which is why he sold it to me; too costly to maintain he said)) or something else?

Post by **Ozark Lee** » 06 Oct 2015, 08:46

The in gear but independent of the wheels turning part leads me to believe that it would likely be the throwout bearing on the clutch.

The throwout bearing is a relatively cheap part but the labor to get to it is pretty intense since the transmission needs to come out. Since it is so labor intensive the proper way to deal with it is to replace the entire clutch assembly which is the clutch, pressure plate, and throwout bearing. While the transmission is out it is also SOP to replace the rear main seal on the engine since it is right there. The rear main seal is another one of those relatively cheap parts that is labor intensive to get to if it fails and all of the labor has been done to service the clutch.

Use the Sachs clutch kit only but shop around. I have found the kits for a bit less money at a local auto parts store than I would have paid through the parts suppliers on the internet.

...Lee

Veilleuxpbd · Post by **Veilleuxpbd** » 06 Oct 2015, 09:56

What would be telltale signs that it is effectively the case?
Also I found that it only happens when I accelerate just quick enough to be pushed back in my seat, and possibly the engine towards the fire wall. Could parts rub together? My engine mounts seem to be good.

Post by **Ozark Lee** » 06 Oct 2015, 16:59

It is difficult to diagnose with certainty via the web, without driving the car. Noises like that are kind of an experience thing, something that is more certainly diagnosed by someone who has had a similar problem before. One other possibility is the bearing on the input shaft to the transmission. There might be some evidence of a failing bearing if you change the lube in the transmission. The gear lube, as is discussed in another active thread by coincidence, tends to stay very clean and clear even after hundreds of thousands of miles. If your lube is discolored and has flecks of metal that would indicate an internal problem in the transmission.

The bad news there is that Volvo doesn't supply repair parts for the manual transmission. I think there are a few aftermarket vendors but you will need to did deep to find them. I think that Getrag was the OEM supplier for Volvo but I am not 100% certain of that. If it is just a bearing, and the shaft is OK, then bearings can be sourced by size but again it takes some digging to find the proper substitute.

...Lee