AWD Transmission: Transmission Whine

[rayyan171]

I don't know why, but I have the feeling that it's something the transmission simply does.

The 2004/2005 ones with the 5-speed Aisin Warner gearboxes seem to have this whine from 30-50mph, which seems to quiten down at higher speeds than that.

If you have ever taken a ride on a bus, a bus makes some sort of loud whine when going through the gears, up to 30-40mph. Other cars do this, one example being the BMW M3 which would whine at high speeds. As 30-50/60mph is high speeds for this large SUV, I have the feeling that maybe it's something the car just has. It is a large car with lots of sound deadening, so maybe its a safety system volvo implemented, for you to have a sense of speed? It hasn't seem to have got better or worse in our XC90 either...

[rsymes2k]

Originally Posted by NCS XC90

Hi, had similar, 30mph to 50mph whine. Ended up changing both rear wheel bearings. It was the passenger side bearing that was gone. There was no way of detecting it until I had it off the car and then you could feel the roughness. I really thought it was the final drive gear, it was exactly that sound but much easier in the end.
Neil

Did your whine disappear with the car in neutral / not under load?

[kevthedev]

Originally Posted by timh30

Hi,

Does anyone else suffer a slight transmission whine on the xc90 ?

On my wife's car it only occurs around 30-50mph (or at least it can only be heard at those speeds), the pitch increases with road speed not engine rpm, and only occurs under load (i.e. when coasting there is no noise).

As it is road speed related, I assume it can only be occurring from the gearbox output shaft onwards. I did replace the spline shaft a little while back from the gearbox to bevel gear, and didn't notice any problems with that (i.e. no observable play and rotated freely).

Hi,i to have a whine on a 2004 xc 90 described like yours to the letter,I have changed the transfer box because a Volvo specialist told me that was the problem,Changed nearside drive shaft,all four wheel hubs/bearings and its still the same no change at all,i now think it can only be transmission related.

[PVSPete]

Years on from the original post, my 2005 XC90 has the same annoying whine between 30 and 50mph which disappears when coasting. Did anyone ever get their whine sorted?

[RoyMacDonald]

In my case it was a wheel bearing.

[Christian]

I have a similar low level, medium pitched whine that feels while driving as if its transmission/bevel related. I have a very low miles (for age) 2007 which I bought with 53k two years ago, one female owner, and changed the trans fluid on purchase (which came out very clean).

In investigating the issue, I found this, particularly about the 3.2 version (which I have, 2007 with 72,500 miles).

My top engine torque mount does have just a little bit of play, so I'm going to troubleshoot it conclusively this week.

https://automotivetechinfo.com/2018/...loping-issues/

Engine torque rod mount causing rattle and grinding sound from transmission area (XC90 2006- WITH SI6 3.2L SIX CYLINDER ENGINES)
SI6 3.2L engine
SI6 3.2L engine
Volvo-SI6-3.2L-engine-shake-torque-rod-listen-for-rattle
When you are checking out a Volvo equipped with the SI6 3.2L engine, make sure you check the upper engine torque rod mount by grabbing it from the bottom and shaking it. If it rattles, replace it. These mounts can cause very strange noises while driving at low speeds, sometimes the noise sounds like a grinding transmission or angle gear.
You may get one of these later XC90s in your shop equipped with the SI6 3.2L short six cylinder engine, with a customer complaint of an intermittent grinding or rattling noise coming from the engine area under light loads. The symptom usually happens more when the car is cold and can sound like there are rocks being ground up in the transmission or bevel gear.

It is difficult to replicate the noise if the car is on the rack with no load on the tires, so you will have to drive it until you observe the symptom.

This sound is usually intermittent and can sound like the drivetrain is ready for the scrap pile, but before you break the bad news to the customer, you should remove the upper engine torque mount and test drive the car again.

The torque mount is on the right side of the engine and is bolted to the right strut tower and the top of the engine block. Like most torque mounts this one has two rubber bushings to isolate engine vibrations from the body.

The bushing that is bolted to the engine is covered by a large cast aluminum cover so it’s difficult to see the condition of the bushings without removing the entire torque rod from the engine.

If the torque rod is worn out, it will rattle around when you grab it from the bottom to check for play. When you remove the torque mount you will usually see the front bushing is cracked and shrunken.

Several shops have mistakenly replaced transmissions and bevel gears to “fix” the noise that can be caused by this torque rod mount when it is worn out. So don’t jump to conclusions when you hear a grinding or rattle noise coming from the drivetrain on one of these Volvo XC90s that is equipped with the 3.2L SI 6 engine.

[piervanz]

Originally Posted by Christian

I have a similar low level, medium pitched whine that feels while driving as if its transmission/bevel related. I have a very low miles (for age) 2007 which I bought with 53k two years ago, one female owner, and changed the trans fluid on purchase (which came out very clean).

In investigating the issue, I found this, particularly about the 3.2 version (which I have, 2007 with 72,500 miles).

My top engine torque mount does have just a little bit of play, so I'm going to troubleshoot it conclusively this week.

https://automotivetechinfo.com/2018/...loping-issues/

Engine torque rod mount causing rattle and grinding sound from transmission area (XC90 2006- WITH SI6 3.2L SIX CYLINDER ENGINES)
SI6 3.2L engine
SI6 3.2L engine
Volvo-SI6-3.2L-engine-shake-torque-rod-listen-for-rattle
When you are checking out a Volvo equipped with the SI6 3.2L engine, make sure you check the upper engine torque rod mount by grabbing it from the bottom and shaking it. If it rattles, replace it. These mounts can cause very strange noises while driving at low speeds, sometimes the noise sounds like a grinding transmission or angle gear.
You may get one of these later XC90s in your shop equipped with the SI6 3.2L short six cylinder engine, with a customer complaint of an intermittent grinding or rattling noise coming from the engine area under light loads. The symptom usually happens more when the car is cold and can sound like there are rocks being ground up in the transmission or bevel gear.

It is difficult to replicate the noise if the car is on the rack with no load on the tires, so you will have to drive it until you observe the symptom.

This sound is usually intermittent and can sound like the drivetrain is ready for the scrap pile, but before you break the bad news to the customer, you should remove the upper engine torque mount and test drive the car again.

The torque mount is on the right side of the engine and is bolted to the right strut tower and the top of the engine block. Like most torque mounts this one has two rubber bushings to isolate engine vibrations from the body.

The bushing that is bolted to the engine is covered by a large cast aluminum cover so it’s difficult to see the condition of the bushings without removing the entire torque rod from the engine.

If the torque rod is worn out, it will rattle around when you grab it from the bottom to check for play. When you remove the torque mount you will usually see the front bushing is cracked and shrunken.

Several shops have mistakenly replaced transmissions and bevel gears to “fix” the noise that can be caused by this torque rod mount when it is worn out. So don’t jump to conclusions when you hear a grinding or rattle noise coming from the drivetrain on one of these Volvo XC90s that is equipped with the 3.2L SI 6 engine.

This is an old thread, but wanted to comment on it anyways.

Bought myself a nice "new-to-me" XC90 3.2 at auction with a diagnosed issue with the gearbox.
Although the car was making some worn bearing like noises under load and at low speeds (even when stationary and in Drive), the car drove just fine otherwise.
Have had the car up on a ramp and even diagnosed this sound (with a stethoscope) coming from the gearbox. Sound was most noticeable on the left side front drive shaft.
All very strange, because transmission fluid was absolutely fine and the gearbox actually seemed recently rebuild due to signs of fresh non OEM rtv sealant. So something didn't add up.

But boy o boy did I finally stumble upon this message after spending many night ons google.

Fixed the upper engine mount yesterday in less than 10 minutes and it indeed was very worn. Installed new OEM mount and hallelujah, no more "bearing" noises from the engine..

Still don't really understand how an engine mount can cause these types of noises, but I won't complain as this fix has most likely saved me up to €2000,- making this great deal of a car an even better one.

Thank you all for your contributions.

Cheers,
one happy Volvo owner :-)