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Replacing just the thrust arm bushings "at the car"

6865 Views 14 Replies 7 Participants Last post by  occhis
Rajaie has a great write-up over at Beisan Systems on changing out e39 thrust arm bushings with the arms still installed on the car. I'm posting my experience here (long) in case anyone else might be thinking of trying Rajaie's approach.

Conventional wisdom is that you need to remove the thrust arms and replace the bushings with a shop press. If you are pulling the arms, though, you probably should be prepared to replace them outright as removal can damage the ball joints. I decided to give the "bushings only" Beisan procedure a shot for several reasons.

- I'd just replaced my struts a couple weeks back and didn't want to lift them out of the hub to pop the arm ball joints.
- I know the arms are at end-of-life but their ball joints are still good.
- I'm cheap. Perhaps the cheapest e39 owner, ever....

I installed a pair of Rein aftermarket bushings made in China. They seem identical in build to the Boges I pressed out. I may end up replacing the entire thrust arms within a year or two anyway but that depends on how well these Reins hold up.

The Beisan procedure calls for a 5-ton 3-jaw gear puller, a special pipe cap, and a press sleeve. I already had the puller. Since I have an i6 car, I bought the 1.5" socket weld cap recommended in the procedure from a local industrial plumbing supplier for $7, and tried to order the press sleeve tool through my local BMW dealer. [Note: the procedure calls for different-sized or psi-rated caps & BMW sleeve tools for the i6 and v8 cars....]

However, my local dealer refuses to order any "tools" so, before placing an order online, I investigated the O.D. specs for socket weld couplings and found that certain 1.5" couplings (full or half) in the 3000 psi category have an O.D. of 57.25 mm -- about .75 mm less than the BMW press sleeve but still wide enough to match up well with the outer steel shells of the bushings. My local plumbing supply had one 3000-psi "full" coupling in stock, for $5. A "half" coupling might be preferable (they're shorter) if your puller is on the small side. If you visit a plumbing supply to get socket weld fittings, take your calipers....

I followed the Beisan procedure pretty much as written. (Aside: Rajaie mentions a hidden, hard-to-reach screw that's holding the front of the air duct on the driver's side. I accessed it from the front of the car bumper, pulling off the small grille piece, loosening the brake duct and getting a socket on it in plain sight.)

All the pre- and post-press steps of this procedure take far more time (hours) than the actual press work, which will be over in only minutes if all goes well. Pressing these bushings in and out of the arms with the tools described was a piece of cake even though I had to do it on my back (of course, with the car on jackstands). I'd say the only thing "hard" about it is getting the sleeve, cap, and puller all lined up and sorted on the thrust arm, but even that is nothing to fuss about.

I've been out and about with the car, have not yet gotten an alignment, but have driven on the expressway at 85 mph and have no vibrations or shimmies (my car didn't have any beforehand). At that speed, the car feels really settled, as if it were going much slower .... Now I know why these cars need an autobahn.

Some Observations

Whether you are replacing the arms entirely or just doing the bushings, you still have all that pre- and post-install work involved.... For the actual bushing press work, using the Beisan approach, after I had the control arm unbolted (bushing end) and lashed to its adjacent tie-rod with thick twine, I spent approx. 10 minutes total per side pressing the old bushing out and the new one in. The time factor here really boils down to how smoothly you are able to line up and center or square all the pieces (puller, cap, sleeve) against the thrust arm. When pressing the new bushing in, I made sure the puller jaws grabbing the other side of the thrust arm would not interfere with the leading edge of the bushing as it came through and exited the bore.

The rubber chambers in the old original (1999) Boges I took out were cracked in several *inside* and outside spots and had leaked out all their fluid (only dried residue inside). I didn't notice the inner cracks until I cut one bushing in half (cross-sectional) with a hacksaw to see how they're constructed. The outer shells are stainless steel and the square inner core the bolt passes through is aluminum.
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Thank you sir for the inspiration! I am planning on doing just bushing before the summer is out.
I'd guess others have done this but I haven't seen anyone mention the Beisan write-up. It is as detailed as anyone could ever hope for. I went into this DIY thinking the bushings would be really tough to press out. Not so. Resistant yes, but nothing at all compared to, say, those rear wheel carrier ball joints. Of course you need a decent puller and a wrench that's long enough to give you some leverage, but that's about it.

My hat is off to Rajaie. This is the fourth Beisan write-up I've followed to this point, and I'm always amazed how well he manages to cover everything involved.
Thank you sir for the inspiration! I am planning on doing just bushing before the summer is out.
On car trust arm bearing puller tool I-6 vs V-8 E39

QUESTION CONCERNING THIS NOTE >> [Note: the procedure calls for different-sized or psi-rated caps & BMW sleeve tools for the i6 and v8 cars....]
Are there different size pusher sleeves for a 530 vs a 540 (v8) when pressing out the trust arm bearings? If so, what are the different BMW tool part nos on the pusher sleeves? I know one number referenced is BMW press sleeve: 83300491942. The 540 and 530 E39 TA bearings are the same so why the tool parts nos are different to push in bearings?
I did this last year basically following the Biesan procedure as well, but I was not so careful to pick a pipe cap with the proper OD. Let that be a warning to others: spend the time and find the right cap. Mine was too small and mushroomed the metal bushing sleeve. Not to worry though, there's another side left, and I used an old brake pad (had it around) to push the bushing in so that it was flush with the arm. At this point the pipe cap could be used since it would not mushroom due to being constrained by the arm.
The Beisan write-up has a table showing differences in the metric dimensions of the tHrust arm BUSHINGS for the i6 and v8 models.

If the 530i and 540i bushings are the same, as you say, then use the sleeve for the 540i. Simple, isn't it? HOWEVER ... I just searched through RealOEM.com and it's showing identical bushing part numbers for all the i6 cars but NOT the v8s, so.... where did you get the information that they're the same on the 530 and 540?
QUESTION CONCERNING THIS NOTE >> [Note: the procedure calls for different-sized or psi-rated caps & BMW sleeve tools for the i6 and v8 cars....]
Are there different size pusher sleeves for a 530 vs a 540 (v8) when pressing out the trust arm bearings? If so, what are the different BMW tool part nos on the pusher sleeves? I know one number referenced is BMW press sleeve: 83300491942. The 540 and 530 E39 TA bearings are the same so why the tool parts nos are different to push in bearings?
Besain

Thanks. That helps allot! I can't believe I have not seen that Beisan bushing R&R piece before. Those bushing press parts have to be ordered from BMW Germany or Baum Tools (more expensive). The BMW dealers won't stock tool parts probably for several good business reasons.
So that others benefit, I'll add a cross reference to one of the thrust arm bushing threads found simply by typing /thrust F3 in the best links:
- Thrust arm bushing replacement for the E39 I6 (1) (2) (3) (4) (5) (6) & V8 540i (1) (2) (3) & thrust arm recommended parts (1) (2) & brand selection (1) (2) & how to make your own BMW thrust bushing tool (1) or buy them (1) (2) or improvise (1)
On car TA bushing R&R

If you have any aftermarket, Lemforder, etc. TA that already had bushings pressed in by the Mfg., It's different from the "BMW original arms in that the bush openings are cut back on the BMW's to allow for strait in alignment and the aftermarket one's do not. Trying to press in a bush into a square cut opening is all but impossible.
The original BMW bushings as well as the aftermarket replacement bushings I installed had beveled edges, so it didn't really matter whether the holes on the thrust arms themselves had beveled edges or not (I don't recall whether I even looked at those). Although I guess for some people that would help. I bet most bushings come with beveled edges, but I haven't seen anything firsthand other than the originals and the cheap replacements I installed.
Installing TA bushes "on car"

Just to be clear, yes all of the TA bushings I have seen have beveled edges. I was referring above to the pronounced chamfer cut on the "BMW" TA's that allow pressing in those bushings without an alignment problem that occurs if one tries to press into a squared edge hole that is tolerance fit.
You were clear enough (for me anyways) the first time but it's a valid point and worth watching out for.

I suppose all bets are off if you are dealing with aftermarket TAs. The Beisan procedure and this thread are for basically the handful of e39 DIY-ers that want to press bushings into original equipment. Most people just buy and install entire TAs with bushings already in them.

Which brand bushings and TAs were you trying to match up or having problems with?
Just to be clear, yes all of the TA bushings I have seen have beveled edges. I was referring above to the pronounced chamfer cut on the "BMW" TA's that allow pressing in those bushings without an alignment problem that occurs if one tries to press into a squared edge hole that is tolerance fit.
Trust arm bushings that are already pressec in TA.

I had replaced both the control arms, thrust arms and front shocks at 62k mi. some 3 years ago. now I'm at 96k miles and the onset 50-60 mph shimmy is building up. So, I had fully replaced the original BMW arms with OEM Lemforder arms with bushings already pressed in. I am using the Beisan procedure with the BMW press sleeve I had to sent to Europe for. It caught me by surprise that after pressing out the 1st TA bushing enough to line up the insertion of the new "BMW" replacement that I was having trouble getting it in strait. Upon looking at my old original TA that I practiced pressing out the original bush...in the vice, I noted the pronounced chamfer cut on the insertion side. Sure enough, that was not there on the OEM Lemforder aftermarket TA. I'm not saying one can't press in a new bush into this. However, not removing the arm and havinging that bush installed with a proper machine press and BMW tools should lead to nervous problems. I threw in the towel and ordered up some new Lemforder TA's with Meyle HD's already pressed in. it's always disapointing to have a 'gocha' pop up as these BMW, if worked on by the book and with proper tools are very strait forward procedures. I now have out my 'monster' modified and welded up ball joint press to proceed taking those TA's out. I think all of this is why BMW dealer line techs throw a fit when someone brings in a car with aftermarket suspension parts installed as they are set up with nice 'on car' bushing presses to quickly R&R those TA bushings. If they see no chamfer, they take the whole arm off and don't waste time trying to press out and in like that.
I agree. The on-car procedure is a pure nightmare. I spent one entire weekend doing one side. Bent a 3 arm gear puller and burnt up an electric impact gun. Finally got it in, though. Bought new arm with bushing installed for the other side.
I had replaced both the control arms, thrust arms and front shocks at 62k mi. some 3 years ago. now I'm at 96k miles and the onset 50-60 mph shimmy is building up. So, I had fully replaced the original BMW arms with OEM Lemforder arms with bushings already pressed in. I am using the Beisan procedure with the BMW press sleeve I had to sent to Europe for. It caught me by surprise that after pressing out the 1st TA bushing enough to line up the insertion of the new "BMW" replacement that I was having trouble getting it in strait. Upon looking at my old original TA that I practiced pressing out the original bush...in the vice, I noted the pronounced chamfer cut on the insertion side. Sure enough, that was not there on the OEM Lemforder aftermarket TA. I'm not saying one can't press in a new bush into this. However, not removing the arm and havinging that bush installed with a proper machine press and BMW tools should lead to nervous problems. I threw in the towel and ordered up some new Lemforder TA's with Meyle HD's already pressed in. it's always disapointing to have a 'gocha' pop up as these BMW, if worked on by the book and with proper tools are very strait forward procedures. I now have out my 'monster' modified and welded up ball joint press to proceed taking those TA's out. I think all of this is why BMW dealer line techs throw a fit when someone brings in a car with aftermarket suspension parts installed as they are set up with nice 'on car' bushing presses to quickly R&R those TA bushings. If they see no chamfer, they take the whole arm off and don't waste time trying to press out and in like that.
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