I seem to have developed a knocking sound under the front drivers side wheel, it also sounds as if the passengers side is knocking but not much.

I've put silicon grease over all the bushes I can see, and checked to see if suspension is ok, all seems fine, and I've had it up on a ramp to look.

I feel it may be the Anti Roll bar bushes, only problem is that you can't buy them, you have to buy the whole bar. I was wondering if anyone had any other ideas in case Im barking up the wrong tree.

 

When is it knocking? On bumps? In turns? Some of that may help in determining what's going on. I would be more apt to think your problem is front swaybar endlinks than the swaybar bushings themselves. Another potential problem could be your strut mounts. - AB

 

Its usually over bumps, but not big bumps, more like rocky uneven tar, usually in a straight line.

 

Hello Mr. Strangedays,

Greetings from windy Chicagoland.

The 850 has notorious upper spring seat for front struts. It is a hybrid part of metal & rubber, and the rubber hole where the damper (piston) rod goes through wear out over time & accumulated mileage, and begins to make noise, as the piston rod moves around. The spring seats are not expensive (about $30 or so each), but I would replace the upper mount as well (this one is expensive, though, about $90 or so each). For this procedure, you'll need a set of spring compressors (and extreme caution) should you decide to repair it yourself. Many suspension parts on Volvos also require that you use new nuts (sometimes bolts as well).

If the above is not the case, it could be anywhere around the front end (takes hours, if not days, to trace the location). My 850 used to make high-pitched noise, and the culprit was a loose bumper mounting bolt. Anyway, take the wheels off and visually inspect all connections. If they do not appear to be damaged/worn out, I assume the spring seats are tired.

Good luck and please tell us your progress.

Regards,


JPN

 

Hello again from Chicagoland,

I forgot to add something, if the upper spring seats were the culprits. Take a look at the following, it's FCP Groton's parts illustration:

http://www.fcpgroton.com/volvo850shocks.htm

If the spring seats are the culprits and if you decide to replace them, make sure to replace the following items as well:

1. Bump stop
2. Special washer
3. Top cap

Regards,


JPN

 

Thanks for your advice, I believe you are probably right on this one as I have visually inspected most of the joints and treated them with some silicon spray, but so far none have been cured, I know a friend who is quite good with the old suspention and has the tools I need, so I may be able to get some quality help on this one.

 

Hello again from Chicagoland.

When you do the repair, I strongly suggest that you use OEM parts (FCP Groton parts are usually OEM, but check with them, I used Sachs, which is one of the OEM MFG's for Volvo. They are either made in Germany or England). I never had good luck with cheap parts, and in the long run the extra cost of OEM absolutely pays off (I once had an Accord and had the clutch disk replaced with aftermarket parts, it failed only after 10,000 miles whereas the original disk lasted for 100,000 miles).

Even though you won't find on Groton's page, they actually carry most hardware (nuts & bolts) as well. Again, check with them via phone call, even if you live overseas they ship overseas.

Have you checked the ball joint recently? Are the boots ok? If there is a slight play (depends on cars, some cars allow slight free play) or the boots are undeniably ripped, you might want to consider doing the ball joints as well. For procedure, please look for my past posts, I wrote somewhere about tips on doing the ball joints.

Lastly, after you are done with the repair, make sure to have the wheel alignment. I suggest visiting Volvo dealer (or shops that specialize in Swedish cars). I had to pay $139 for the alignment for my 850, your eyes may be popping out now, but Volvo suspension, especially the rear, is much different from others and generic town garages may not know the specific procedures or have the proper alignment equipment (Volvo uses laser-type equipment).

For experts: Please correct me if I'm inaccurate in my opinion.

Good luck and don't hurt yourself during repair. I used my set of spring compressors (Blue-Point), plus I rented out another set of compressors from local Autozone and used a total of 3 compressors just for added safety. Also, a good quality torque wrench is a must for this repair (I used Snap-on, 200" lbs - 1000" lbs range. For ft. lbs conversion, divide those numbers by 12 [17 ft. lbs -83 ft.lbs]). Some nuts require "angling" using angle-wrench, but I just put a mark on each nut with correction fluid and eye-balled them.

Please keep in mind that safety is first, especially with the spring.

Best regards,


JPN

 

JPN is correct!

Front upper spring seat...notorious to go out on the 850s. Makes an annoying clunking noise when you hit a bump or even turn when the car shifts it weight. Approx. a 35 dollar part, but labor is probably gonna be around 100. Definately do both sides!!!!

 

I think ill probably change the shocks as well

 

Greetings from Chicagoland.

I hope you won't have difficulty removing the strut retaining nut like I did. Mine was tight, and the hex hole on top of the piston rod stripped, rendering it useless.

I had to use two different techniques for R/L. For Right, I had to wedge a 6-inch prybar (Snap-on) in the slots on the special washer to keep the piston rod from turning. For Left, the above method failed and I tried to destroy the retaining nut physically with a chisel & a hammer, being careful not to damage the threads on the rod since I was going to reuse the strut (I decided to buy a nut breaker afterwards). I destroyed it almost in half, but then I decided to give a hit on the top cap with a chisel & hammer strategy (In my case, chisel + hammer combo is imperative when working on Volvo). It turned. I hit the cap in the loosening (CCW) direction.

The new nut couldn't be torqued to spec (52ft. lbs/624" lbs), as the rod kept wanting to turn even with strong grip with a locking plier (vise grip). But since the nut is an oblong-shaped self-locker, I torqued as much as I could and put a torque mark with correction fluid. It's been almost 3 months since the repair but the nut has not moved even a hair.

There is also a cross-shaped retaining nut, which the dealer uses a special tool to remove. The special tool is available somewhere on-line, but mine was not that tight and came off easily. If yours is tight, you could try a pin/drift punch and hit it with hammer. This nut is re-useable I believe.

My 850 has Bilstein strut and so far it served me very well. Good luck and be careful when you compress the spring, and make sure to get new nuts for the struts & mounts.

Regards,


JPN