Getting closer 87/240 wagon rear thumps....

Harry von Zell · Post by **Harry von Zell** » 29 Mar 2007, 07:27

Well I've replaced the tranny mount and still getting bangs/thumps, clearly in the rear area when car moves off a dead stop. Problem is worse on wet roads.

Mechanic says it may be the bushings connecting the rear axle.

Looking around ( I'm not a smart car guy) I see that there are a number of busihngs in the rear area.

Does anyone have a suggestion on which bushings are "most likely" to be the problem?

When car starts from a dead stop I get (and feel) a Bang just at the very first sign of forward movement.

I love bricks, but this is driving me bonkers!

Thanks to all,

Harry

Post by **billofdurham** » 30 Mar 2007, 12:03

Harry,

Really difficult without crawling underneath and poking around. There are 8, possibly 10 bushings (depends which manual you read) on the rear axle.

The 2 support arms, big lumps of metal that the rear axle sits in, would be my first suspects. They have two each, one back and one front. A visual check would probably not show too much, so the car should be jacked and supported and a large bar inserted near the bushings to see if there is excessive movement.

Next would be the torque arms, sometimes called support stays, which come off the top of the axle and down to a brackets which attache to the support arms. Again a large bar near the bushings would show up any play.

Last is the cross stay which attaches to the left side of the rear axle and to a bracket above the axle on the right. This one, I think, would tend to give noise more on an up and down movement as it is there to act as a damper.

Bill.

Harry von Zell · Post by **Harry von Zell** » 30 Mar 2007, 14:40

Thanks Bill, I'll print out your comments for my mechanic.

I believe he thinks it might be a "Trailing Arm" bushing, but I'm going to ask him to check out the things you mention before we go nuts on buying parts.

I do appreciate your help (as I mentioned, I'm not a car guy) since the banging of the rear end (especially when wet) scares the crap out of me. I get visions of dropping the rear end in the road LOL!

I'm hoping the bangs are more an annoyance than a hazard.

Harry

Post by **billofdurham** » 30 Mar 2007, 15:35

The trailing arm is the torque arm/support stay. If you look at it, it trails from the axle to the rear.

I once had the misfortune to drive a Vauxhall Victor (GM subsidiary) which had bad trailing arm bushes. On hard acceleration from rest the rear of the car actually went sideways. I don't know if it made a clunk but I know my heart made quite a few.

Bill.

Harry von Zell · Post by **Harry von Zell** » 30 Mar 2007, 16:50

Bill, I found a great rear suspension parts list and diagram:

www.fcpgroton.com/volvo240rearsuspension.htm

If you get a moment could you look it over and see which "parts" may be the most likely to fail and cause my thumps?

Thanks,

H

Post by **billofdurham** » 31 Mar 2007, 12:20

Harry,

Terminology seems to change mid-Atlantic.

Those that I would suspect first are 2 & 3.

Next would be 7. Unless you intend keeping the car for the next 20 years go for the cheaper version if you need to replace these.

Last 4 & 5.

That is a good reference page. Never thought of looking there. It would have saved a lot of book reading.

Bill.

CarVolvo · Post by **CarVolvo** » 31 Mar 2007, 23:21

i would say it might be irritating but as long as you change it it might not be as dangerous as if that thunking had to do with your rear shocks. Most 240's particularly wagons seem to lose that rear shock housing which rusts through and eventually break.

Hopefully your mechanic has observed whats going on before he sent you out for the drive. You could most likely jack up the car using proper safety measures and kick at the back to reproduce the effects or observe the rear shocks to see if they are in good shape.

Im trying to figure out why the car would appear to have more clunking in wet weather. You would think that the rain would help cushion the sound or keep the part more "lubricated" than in dry weather?

Harry von Zell · Post by **Harry von Zell** » 01 Apr 2007, 06:45

CarVolvo and Bill. Thanks for your efforts. It is appreciated.

My mechanic also said to go with "2 and 3" from the diagram.

I'll also point out the shock housing issue to him.

On "wet" roads the banging is more frequent and harder. It almost seems that the drive train moves forward during braking and back when movement starts. Thats the "feel" I get while driving, and we replaced the tranny mount first, but it didn't solve the problem.

I'm not giving up as I'm challenged to find out whats going on.

Thanks again.
Harry

CarVolvo · Post by **CarVolvo** » 01 Apr 2007, 09:34

I would suspect that the tranny mount would give you a different feel than the other parts of the suspension. I often wondered if i could just put in an "hockey puck" in there.

I would think if its something to do with the rear suspension as Bill mentioned since this is a rear wheel drive.

Harry von Zell · Post by **Harry von Zell** » 07 Apr 2007, 15:33

Bill and CarVolvo,

Hat the trailing arm bushings replaced this moening and my Drive train is as thight as a...... (nevermind)...

Thanks for your sage advice!!!!

That's the last of my "HAVE-to-do" items, now on to the "NEED-to do" stuff.

I'll probably be "pulling on your sleve" again.

Thanks!!!!

Harry