About to buy an 850, but there's a strange noise...

Jonesy · Post by **Jonesy** » 13 Oct 2007, 19:04

I am new to the forum, I live in Australia, and I am looking to buy an 850 (possibly 2) as they are great cars. I found one yesterday, a '93 with high miles, but it is utterly immaculate inside and out, and is rediculously cheap. It is owned by an ex mechanic, and has a full service history. It does have one problem though, a noise from the drivetrain (I think) a kind of low pitched sound beneath the engine sound. It is almost like a low moaning sound, quite loud. The transmission shifts perfectly, and the sound is not there when the engine is revved in neutral. I really can't figure it out, and the elderly owner is so hard of hearing that he can't really hear it.

Hope someone can shed some light for me, I finally have moved to a house with a garage so I look forward to being able to doing my own maintenance, I really enjoy looking after my own car repairs, I hope I can become a useful forum member.

Post by **Ozark Lee** » 13 Oct 2007, 20:23

My gut guess is that the car has an issue with a front hub. At what speed does it start to get noisy?

...Lee

Jonesy · Post by **Jonesy** » 13 Oct 2007, 21:37

Thanks Lee, it gets most noticably noisy from about 30MPH onward. A low sound, not grindy or anything like that, but very noticeable beneath the engine noise. The transmission seems to operate perfectly, so I wondered if it could be post-transaxle. Can you suggest anything I could look at to narrow the search?

Post by **Ozark Lee** » 14 Oct 2007, 04:48

My only experince with a bad front hub was on a Jeep Grand Cherokee. In that case you neither heard nor felt anything out of the normal until 45 MPH. It then growled, vibrated, and was very unpleasant to drive.

In the case of the Jeep the hub otherwise felt fine when I jacked the wheel off the ground and tried to "flex" the wheel up and down. The bearing never got loose.

It is my understanding that Volvo hubs tend to give a better affirmative indication when they start to go bad as they get loose. If you jack the wheel off the ground and can feel play in the hub it is bad for sure. The trick is to differentiate play in the hub from play in the ball joints (vertically) or tie rods (horizontally).

The other candidate for a problem is a CV joint but they tend to make more wierd noises at low (parking lot) speeds in turns rather than higher speeds.

...Lee

Koan · Post by **Koan** » 14 Oct 2007, 08:28

Hi -

Here is something to consider: The noise will probably change with either engine speed or car speed. If it changes with car speed it could be anything form the output side of the transaxle downstream. Hoping it is not the transaxle itself, that pretty much leaves CV joints and hubs (assuming front). I had a bad front hub, and it had a growling noise above 30mph. Turning right or left (sorry do not remember) at the same speed would reduce the noise, and sometimes applying the brakes - even gently - would quiet the noise as well.

The hub was damaged after I hit a cinder block with the passenger side front wheel, but it took nearly 6 months to get to the point where it was noisy.

The best way to check for sure is to remove the wheels and the brake calipers on the front and check for bearing play. If the hubs are OK, then you can focus on the 4 CV joints - first looking for a torn boot which may have allowed contamination.

If it is the bearing hub - this needs to be fixed soon as you may see your wheel passing you down the street.

Hope this helps.

Koan

Jonesy · Post by **Jonesy** » 14 Oct 2007, 18:12

Thanks for those tips, I will try getting the front wheels off the ground and take a look at the hubs and CV's. I guess that if it is a transmission it would pretty much cost as much as the car is worth to fix.

Koan · Post by **Koan** » 14 Oct 2007, 19:05

Prior to disassembly, try to check if it is better turning in one direction (at higher speeds) and worse in the other direction. Do not apply the brakes during this test (naturally please do so if you must stop for something - shame we live in a litigious world). If is does get better turning one way and worse the other the bearing hub is more than likely the culprit.

Koan

Jonesy · Post by **Jonesy** » 14 Oct 2007, 20:42

Thanks Koan, I will try it out. Is a wheel hub repair a reasonable DIY or would it be best sent to the shop?

Koan · Post by **Koan** » 14 Oct 2007, 21:25

Jonesy

This is a hard question as I do not know you.

I have performed many repairs myself, and feel I could do this as well, but when mine needed to be done I was already in the the tire shop for new tires. I asked them to give me a break since they already had the tire off. I would have tried it myself, but did not simply because of the circumstances.

So even if I understood your background and capabilities, I do not have first hand experience. I found a good diagram on what is involved and suggest you look and make the call yourself. here is the web address (sorry to go out of your site Matthew)

http://volvospeed.com/Repair/FWDbearingHub.php

This goes into a good level of detail. Two obstacles for me would be the lack of an E 14 torx socket and a 36 mm air socket.

Hope this helps

Koan

Jonesy · Post by **Jonesy** » 16 Oct 2007, 01:41

Thanks Koan, that looks like something I can handle. I really appreciate your help...