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View Full Version : Anyone changed their trailing arm bushings???



Robert K
07-10-2006, 09:55 PM
As mentioned in another post, I've changed about all of my other suspension bushings in the past couple of weeks. The only thing left is the trailing arm bushings. After the mess of pressing the new 750i thrust arm bushings in, I'm a bit apprehensive about tackling the trailing arm bushings, although I feel it would be a good thing to go ahead and put the new Meyle bushings in that I purchased from BMA. I suppose I'm looking for someone who's done it to describe how and lend a little moral support. Any help or links to help would be appreciated. I've done searches here and at...gasp...Roadfly, plus Google and haven't had much luck.

Grace and peace,

Robert K
1991 535i

yaofeng
07-10-2006, 10:04 PM
If you could tell me what the trailing arm bushing is I can tell you if I have done it or not. I think I have replaced all suspension parts with the exception of the rear strut on my 525. Yes the new pair of rear struts are in my garage. Can't find time for them yet.

Jon K
07-10-2006, 10:18 PM
Im a master at rear suspension - ask E34 530. Anyway, trailing arm bushings are referred to as "dog bones" I think. Or pitmans.

yaofeng
07-10-2006, 10:29 PM
I take it back. Apologies. I did the dog bones for the rear stabilzer bar. But I did not do the rear pitmans.

Robert K
07-10-2006, 10:42 PM
I would have thought that my description was pretty self-explanatory. The trailing arm is the large rear suspension member that the rear wheel bearing and brake parts are connected to. This arm attaches to the rear suspension subframe at two different points. At each one of these points, there is a bushing. That is the bushing I'm talking about changing. If anyone has changed those bushings themselves, I would like to know how they did it.

Grace and peace,

Robert K
1991 535i

Russell
07-10-2006, 10:49 PM
sub frame bushings? I have heard they are a pain. Plenty of stuff in teh archives.

joshua43214
07-10-2006, 11:12 PM
Technicaly they are not trailing arms, but controll arms, and they suck to replace. unless the bearings in them have failed, leave them alone. even with the factory tool it is a total pain.

Bill R.
07-10-2006, 11:37 PM
has its fastening or pivoting point at the body, thats the leading end of the arm and the trailing part of the arm fastens to the wheel hub or axle. So the assembly is perpendicular or fairly close to perpendicular to the rear end or axle. A control arm pivots in the other direction
Here's a picture of the e34 trailing arm and where it pivots from




Technicaly they are not trailing arms, but controll arms, and they suck to replace. unless the bearings in them have failed, leave them alone. even with the factory tool it is a total pain.

joshua43214
07-10-2006, 11:46 PM
Cool, thanks Bill, in my minds eye, they always pivot on either side of the axle for some reason. Maybe I've just worked on too many Jags and my mind is just numb.

next thing you know I will be drinking tea....with milk in it(do people really do this?)....and eating other peoples biscuits when I go out.

fujioko
07-11-2006, 04:48 AM
Hello Robert K,

I’m still in the process of changing out the trailing arm bushings…
First attempt… I fabricated a special tool using my lathe… that didn’t work…
Second attempt…I took the trailing arms to a local shop and had them press the old ones out and press the new one in…

I told the dude at the counter the bushings were asymmetrical and had to be pressed in a certain way.. Of course that little bit of info never made it to the machine shop.

I picked up the trailing arms and brought them home without checking the bushings…Yep they were wrong.

Back to the machine shop I went.. this time I had written instructions and a phone number so they could reach me if they had any questions.

A week went by and no call. I went in last Sunday and inquired about the trailing arms… Nothing was done because they did not understand what asymmetrical was. (Evidently that’s a $10.00 word)

I drew a picture for the guy and he understood. The arms should be ready today!

My advice is to take the arms to a machine shop. Attach a diagram to the trailing arm.
Do not use the word “asymmetrical”…. just a picture will do.

Best of luck!
.

fujioko
07-11-2006, 04:57 AM
Oh, yeah..

The tool I fabricated was very well built. I used a 12 ton ram in a fixture and it crushed the tool before the bushing would even budge.

There is a tool available on ebay but in the long run it may be cost effective just to have the bushings pressed by a machine shop.

The cost was $80.00 for the labor + whatever I paid BMI for the parts.

Robert K
07-11-2006, 06:43 AM
Like I mentioned earlier, I just pressed new bushings in the thrust arms this past weekend. I found an ag shop that had a huge hydraulic press. Once the bushings started moving, they came right out. But it took A LOT OF FORCE to get them moving. I imagine the trailing arm bushings would be the same. I would think one of the main problems with pressing the bushings out of the control arms would be situating them in the press properly. I may check with a friend who has a local shop that isn't afraid to work on German cars (the guy has a 930 slantnose Porsche and an M3). I think I'm going to ask for a quote and see what he says.

Grace and peace,

Robert K
1991 535i

gale
07-11-2006, 06:27 PM
Robin & I replaced the rear trailing arm bushings in his 535i awhile back. The old bushings were in there pretty tight. I forget what size press it was, either a 12 or 15 ton. Barely adequate. I machined press fixtures and a piece of pipe to fit between the 2 bushing housings & with heat & WD-40, we were barely able to get the old bushings to budge. The new ones were tighter than I expected to press in, a 20 ton press would have been better.

We did the 1st one with the hub & rotor still attached & that made it awkward to manage in the press, the second one he had the rotor off & I think the hub as well, & was alot easier to handle.

In retrospect, his old bushings didn't seem that bad.

I did similar bushings in my Alfa Spider by using a hole saw in a drill without the center pilot, and drilled the rubber center & sleeve out from each side. That left just the outer metal shell and I was able to cut a slit in it with a hacksaw, being careful not to cut into the arm but did leave a shallow scar, and then it just fell out on it's own. I don't have a press at home & pounded the new ones in with a socket & 4 lb. sledge hammer, after heating the arm locally with a propane torch & putting a little motor oil on the new bushing.

Robin-535im
07-11-2006, 10:53 PM
In retrospect, his old bushings didn't seem that bad.

In retrospect.... I wouldn't recommend replacing them unless you know they are bad. I figured it would be nice to have them all renewed, even if just for mental calmness.... but it wasn't easy! The old ones looked fine, and perhaps a little stiffer than the new ones from age. No tearing or dry rot noticed.