V70R Sound from rear going over bump: "bong" Bump stop 9157311

Post by **jmailloux** » 25 Jul 2010, 09:25

Hi all,

I have 1998 V70R, about 150k, all stock suspension, original nivomats and springs still on the rear. I occasionally, but more and more frequently, get a "bong" sound from the right rear when going over a speed bump, or coming in my driveway (which is at an incline from the street, so some suspension movement there). I have tried to read up a bit on the topic on various searches here. I have raised that tire and tried to wiggle it, but no play that I can feel at 3 and 9 o'clock, or any other position. I took a look underneath, and nothing obvious is wrong back there. I do carry a heavier load at times, and the rear seems to level still after a few miles, but maybe not at much as it should; it's hard for me to tell, since I've had the car since 2000 and didn't load it up much then (now the kids are getting bigger and we are doing more stuff the entails big piles of crap).

Am I looking at new nivomats? New rear springs as well or not? Or IPD sway bar time? Or is this something else entirely? Or do I ignore this for now?

I had OEM front struts put in at about 104k, if that matters. Other than that, no suspension work, all OEM.
Thanks,
Jim.

FCPEURO · Post by **FCPEURO** » 25 Jul 2010, 09:45

I would look for loose suspension parts. It sounds like something is moving and it shouldn't be. Either that or you have a rubber bushing that is so worn out that the metal is contacting each other when you hit big bumps.

The last thing I would look at is the shocks, but if there are leveling, then they are probably fine. Just check the connecting points.

Post by **jmailloux** » 15 Nov 2010, 23:50

OK, it's been a while, but I pulled a rear wheel and started poking around again. Here are two potential problems I found that may be making noise:
First, there appears to a rubber part of the spring stop (?) broken loose and rattling around inside the spring coils on both sides of the rear springs. Given the dirt and clean areas, it looks like it broke loose from the top area inside the spring coil. It is the reddish sort of rubber object at the bottom of the spring, inside the coils in these photos:

: V70R rear1.jpg (100.3 KiB) Viewed 3957 times

: V70R rear2.jpg (54.02 KiB) Viewed 3957 times

: V70R rear4.jpg (105.96 KiB) Viewed 3957 times

So the question is, what is this thing bouncing around inside my spring coils? Given the hole in one side of it and the similar hole in the upper black area inside the spring, I think it was mounted up at the top end of the springs

And, how important is it?

Next, there is a hard point just in board of the rear jack points; it is a ring of steel with a bolt head in the center. There is a bushing of old (12 year old) rubber or something on that bolt. On one side of my car, that bushing rotates freely, and I can move it up and down 1/2" or so on the bolt shaft. The bolt seems tight (to my hand, did not put a wrench on it). The other side is tight, and the bushing does not move at all in any direction. Here's the picture of the bad one:

: V70R rear3.jpg (116.43 KiB) Viewed 3957 times

You can see some of the gap between the bushing and the surface.

And so again, what is this thing? How important is it? And how do I fix it?

Could either of these things be making a bong or metallic sound as suspension recovers after a bump? That is, I hear the sound as the suspension is extending again after going over speed bump, say.

Thanks for any help.

Jim.

VolvoTurbo850 · Post by **VolvoTurbo850** » 15 Nov 2010, 23:56

your bump stops fell off..buy the kit to get them mounted again. So now you know what they are called that

~

www.fcpgroton.com/product-exec/product_id/7134/nm/1993-1997+Volvo+850+Rear+Bump+Stop+Retaining+Pin

and perhaps this can help your second issue...

www.fcpgroton.com/product-exec/product_id/21061/nm/Volvo_V70_AWD_Rear_Shock_Mount/category_id/181

Post by **jmailloux** » 16 Nov 2010, 15:02

Hey VolvoTurbo850,

Thanks for the great reply.

You were dead on with the bump stop retaining pin. I went down to the dealer and talked to the parts guy I know, and we went through the diagrams. Volvo doesn't sell that pin typically as a solo item, but with the part number from that link, I got two of them for about the same price as FCP. Not that I don't want to give business to FCP, but I don't want to pay more in shipping cost than the part costs. Now to see how to put it together, hopefully without having to pull the suspension apart.

The other part is, unfortunately, not a shock mount. I had the parts guy punch in the part number from the FCP link, and that is the upper shock mount for the Nivomats. Probably I wasn't too clear in my explanation of where this piece is, since I had not seen a diagram of that area with names for the parts. Turns out that piece is part of the rear jack point assembly, and Volvo does not sell the bolt or bushing that goes with it separately, only as part of the whole jack point assembly, at $110. For that $, I think I will ignore that issue for now, as I don't think it is part of the problem.

Any ideas on how to secure those bump stop retaining pins? One end looks like it will secure itself, but the other end is a smooth shaft. Not sure how that is going to work; won't it just fall out again? Or do I glue it in or something?

Thanks
Jim.

Post by **MadeInJapan** » 16 Nov 2010, 15:26

Ah yes, actually, there's a write-up on how to do this: http://volvospeed.com/Repair/SpringBumpStop.php
I have the pins too (have for years) ready in case either of mine fall but so far so good.

VolvoTurbo850 · Post by **VolvoTurbo850** » 16 Nov 2010, 17:21

Happy to help a fellow Volvo enthusiast.. specially and R!

Let us know if that bumped off that issue

. I will be taking a few cars apart before the end of the year so if I can get that bolt off and send it to you if you need it.

G.

Post by **jmailloux** » 16 Nov 2010, 23:35

Thanks for the write up. Looks doable; I will give it a go maybe next week.

For VolvoTurbo850, I may take you up on that offer for that bolt, bad puns and all! . I will take a look at pulling it soon and see what I have, what kind of bushing it is. Maybe I can make a bushing out of some bushings I have left over from my 1979 Int'l Scout days.

Jim.

Post by **jmailloux** » 23 Nov 2010, 21:32

Update on the bolt in the rear jack point (last photo). This bolt does not have rubber bushing, but rather an almost 1/4" thick washer (that was coated in rustproofing). The other side was tight, and was probably torqued up around 90-100 fb lbs. The one that was loose was really loose, almost did not need a wrench to turn it. Had backed out about 1/2 inch. After looking at all the bolts for this rear jack point, it looks like part of the rear jack point's function is to help anchor the suspension arm that runs forward from the rear suspension to the body. If this bolt was loose, maybe this area is what was making the noise when coming off a bump.....or at least that's the theory I am going with for now. Tightened it up good (90 ft lbs or so), and checked all the other bolts in that area I could find. We will see.....
Jim.

Post by **jmailloux** » 08 May 2011, 19:10

Update: After tightening all those bolts around the rear suspension, my bong noise went away and has not come back. One thing fixed....

My bump stops are still a problem. Turns out that the V70R 1998 has a different bump stop than is featured in the fix write up listed above by a helpful forum member. Mine don't look like the ones in the pictures in the write up, and the part number of my fallen bump stops is 9157311, "buffer", as it is listed on Swedish Auto parts. So, I don't know if anyone knows if a v70R's rear bump stops can be put back up without taking apart the whole rear suspension or not, but please let me know. For now, I will ignore them, but I will try to research it a bit more. Hey, I have two new pins for putting up a V70 rear bump stops if anyone wants them....
Jim.