The Volvo Parts, Accessories &
Performance Specialists Since 1963

Rear Wheel Drive Clunk In The Trunk - VIDEO TO SCRIPT POST

2012-05-09 - ipd staff

Cameron from IPD goes over the common reasons why the rear end of your 200, 700 or 900 series Volvo may sound like a box of rocks.


"All right Cameron here from IPD and we're going to talk about a real common a question that we get and something that comes up pretty often especially on these to 240's it's a call about why does the back of my car clunk over bumps and why do I get creaking from the back clunking from the back any of those things. These cars gracefully age they tend to develop a few unique noises that are usually easily curable with a couple small changes.

First one we're going to talk about in the back end is the rear trailing arm bushing. It's a real common one that comes up especially if your car has not had it done before it's not a a lot of cars that are still wearing them original ones, but some of them are. If we look up here this piece is our rear trailing arm there's a small bushing on the front, but the one we're going to talk about right now is this guy on the back. There's a big bushing right here that presses into these gears that come off the rear end and it goes in that way. It's got a big through bolt through it. If we're looking at the bushing off the car it looks just like this pretty big bushing the biggest one you're going to find on this car.

A couple important things to note on it is this it's got the little voids here and there. It's designed that way from Volvo to keep it a little bit more comfortable and to have some articulation in there so it can move properly. The downside of that though is that as time goes by and the rubber ages, it's going to tear and it's going to crack. It just happens it's rubber it's not a bad thing, it's just a wear item. But what happens when that happens is that this center slope that goes through can become off-center, and it can just rock around in there and that translates to when you're driving the car is that box of rocks noise in the back. Sometimes over a bump you'll feel it as is a kind of a rumble, you'll hear it clunk and all that is is when it's happening in this piece is just moving around in there, it's letting everything else move a little too much and this piece just rocking around in there is going to cause a lot of noise cause rattles caused all kinds of things that are no fun when you're driving. The car can get really annoying every day.

So solution for that is bushing replacement if you're going to replace it consider either going original equipment just like this one, or another option that you have is a polyurethane bushing to replace it.I comes with a whole new sleeve goes in there it's a much more permanent solution and will last way longer but it's also going to bring in some additional road feel, that's a good thing if you like to drive it real sporting like but not necessarily a great thing if you just want it nice and fun comfortable ride. 

Another important thing to note on these trailing rod bushings is that this installation is not really a DIY friendly job because it does require a special tool that's unfortunately no longer available. The good news is is that any Volvo dealership or your favorite independent Volvo specialist shop is going to have this tool. The reason this tool is required, is if you look up here, there on that other piece you can see likely trailing arms or whatever else, you can remove from the car and press the bushing in and out with the press. On this the shell and the bushing is pressed into these ears that are welded right onto the rear end of the car. So it actually has to have it driven in and out on the car, that's why it needs the special tool. Something to take into consideration when you're replacing this part. 

Another common piece that we have on the back of these that can make some rattles and noise is the rear torque rods. The rear torque rods are these pieces right here. There's a matching one on the left and right hand side on the backhanded bolts to these ears that come off the rear end. On the front they bolt to the body right here. The purpose of the torque rod is as part of the four-link system and it helps to take the rear end and keep it properly rotated front to back. This way as you're driving the car on these they use the same bushing in the front and the back and on both sides. So it's just a quantity of four of these bushings and similar to the trailing arm bushings you'll get some clunking back here when these bushings are done and failed. You'll get some rattling things like that it's just kind of a thing where same idea the bolts in the center as the rubber bushing ages are going to start rattling around in there and moving around and anytime you have excess movement in play. That's going to mean excess noise and vibration and clunks and stuff like that a couple things to be aware of when you're looking at these is that there are two different styles of bushing used I'll show them to you both right here. 

See one of them is all rubber and that's this one and this fits the early cars about 1981 and earlier this particular car we have on the lift is a 79 so it uses this style solid rubber press in bushing easily installable at home it's not that bad of an install pretty easy. These were pretty stout bushings you don't see failure on these ones so that rapidly as you do on the later style ones and I'm going to show you that later style one right here. These later style ones that they used on the 82 and later have a steel sleeve vulcanized the outside of the rubber bushing and these ones are a little bit more of a pain to install because of the sleeve it requires a pass get in and out but not that big of a deal as far as bushings go when you look at this you'll see that there's a couple of little voids here in here and similar to the rear Trianon bushings that's for a little more compliance on a little more movement but that also means that they're going to wear out faster no big deal to replace them like I'd say it's just a little bit more of the press but either one of these bushings options is going to be a good replacement just be aware of it when you're looking at your car it's not uncommon to see some of the later car swap to the earlier style and vice versa a lot of times cars just got replaced with whatever was around so even if you have a late model and you think you have these or if you have an early model and you think you got these it's worth a look underneath just to confirm that. 

So while we're on the subject back here if something is wearing out it needs to be replaced you might consider doing a performance upgrade at the same time the first version that we'll talk about for performance upgrade is going to be just upgrading to a polyurethane bushing and that is what this bad boy is all it does is replace the stock ones with a better polyurethane one this is going to mean firmer suspension a little more road feel which is a good or bad thing depending on what you're after if you want a car that's going to be a little more responsive and handle a little bit better and have a much longer lasting bushing this is the option for you. Another thing to consider if you want to have some real adjustability in there is this these are our IPD adjustable torque rods they come in a pair and they're adjustable length they just loosen up like this you can adjust them to whatever length you need the other advantages is they come with polyurethane bushings already installed so all it is is a simple bolt-on affair. Now the reason you'd want an adjustable one in this application is if you're changing the ride height of your car mainly if you're lowering the car what happens with the four-link system as you lower the car with the static link stock bars is that the axles going to want to rotate a little bit off because of the change in ride height with these adjustable torque rods you can compensate for that you just have to take a few measurements and adjust them in and you can perfectly square that rear end under the car.