Removing Thrust arms on E34

[FWinNH]

OK,

I had my first go at replacing the thrust and control arms on my '94 540iA this evening. The balljoints on the control arms are gonzo and the thrust arm bushings are shot (standard 60 mph braking shimmy) so I figured I'd replace both of the arms (on both sides obviously) and refresh the front suspension. With 115k miles on them they don't owe me anything.

So anyway, everything looks fairly straight forward *except*... How the heck are you supposed to remove the Bolt and Nut at the bushing end of the Thrust arms? The bolt head is easily accesable, but there is no way I can get any kind of wrench on the nut end. It's wedged in behind and between the round section cross-member and frame so tightly that I can't even get an open end wrench on it to hold it and try to spin the bolt, though that would be a less than desireable method.

Anyone done these on a 540 before? I'm guessing from the descriptions I've read online and in my Bentley that there is more clearance in that area on the 6 cylinder models or in other years. They don't mention doing anything fancy or having to remove anything to gain access to the nut.

The only thing I can see doing is removing the sway bar mount bracket and moving the bracket and sway bar down and out of the way? Of course that bolt would not budge for me and I don't have an impact wrench (yet), but that may be my next purchase... ;-)

TIA,
--
-Fred W

[Bill R.]

proto, some matco, sears craftsmen professional etc they will have nice thin strong walls on the box end that will slip over the available clearance... If you only have the regular craftsmen with the clunky thick walls then it won't fit. This is the modification that bmw shows to do to a 22mm open end wrench to get it to fit or you can do like George Mann did on his e32 and drop the sway bar on both sides to get roomhttp://www.bimmernut.com/%7Ebillr/images/22mmmodify.jpg






OK,

I had my first go at replacing the thrust and control arms on my '94 540iA this evening. The balljoints on the control arms are gonzo and the thrust arm bushings are shot (standard 60 mph braking shimmy) so I figured I'd replace both of the arms (on both sides obviously) and refresh the front suspension. With 115k miles on them they don't owe me anything.

So anyway, everything looks fairly straight forward *except*... How the heck are you supposed to remove the Bolt and Nut at the bushing end of the Thrust arms? The bolt head is easily accesable, but there is no way I can get any kind of wrench on the nut end. It's wedged in behind and between the round section cross-member and frame so tightly that I can't even get an open end wrench on it to hold it and try to spin the bolt, though that would be a less than desireable method.

Anyone done these on a 540 before? I'm guessing from the descriptions I've read online and in my Bentley that there is more clearance in that area on the 6 cylinder models or in other years. They don't mention doing anything fancy or having to remove anything to gain access to the nut.

The only thing I can see doing is removing the sway bar mount bracket and moving the bracket and sway bar down and out of the way? Of course that bolt would not budge for me and I don't have an impact wrench (yet), but that may be my next purchase... ;-)

TIA,
--
-Fred W

[FWinNH]

proto, some matco, sears craftsmen professional etc they will have nice thin strong walls on the box end that will slip over the available clearance... If you only have the regular craftsmen with the clunky thick walls then it won't fit. This is the modification that bmw shows to do to a 22mm open end wrench to get it to fit or you can do like George Mann did on his e32 and drop the sway bar on both sides to get room


Thanks, Bill. So you are saying that it is SOP to just hold the nut and spin the bolt for both removal and torqueing during replacement? I suppose I could just get a cheap wrench (22mm or 7/8" ) and grind it down that way.

-Fred W

[632 Regal]

Hi Fred, I do believe some cars have more room than others. Mine was a total PITA even after I cut a wrench down it dont help much.

I had to drop the cross tube to get to it. Also you have to tighten these bolts under load which again wasnt really accessable. What I did was assemble it and snug it up so that the bushing was still able to move, then tighten the cross tube, tighten the bushing in position, then drop the cross deal again to remove the wrench.

A real chore compared to the lucky folks with more room.

[FWinNH]

Hi Fred, I do believe some cars have more room than others. Mine was a total PITA even after I cut a wrench down it dont help much.

I had to drop the cross tube to get to it. Also you have to tighten these bolts under load which again wasnt really accessable. What I did was assemble it and snug it up so that the bushing was still able to move, then tighten the cross tube, tighten the bushing in position, then drop the cross deal again to remove the wrench.

A real chore compared to the lucky folks with more room.
Thanks, Jeff. It does suck. One would think there has to be a better way. Like weld the nut to the plate or something...

-Fred W

[632 Regal]

yes but thats a lock nut and your "supposed" to replace it once its used, One time use nut. Next time im in there im going to put the bolt in from the rear to make tightening it more accurate, I mean I have to drop the tube anyways.


Thanks, Jeff. It does suck. One would think there has to be a better way. Like weld the nut to the plate or something...

-Fred W

[FWinNH]

Yabbut... If it's welded in place you don't ever have to worry about that sucker coming loose again! ;-)

Could always throw a lockwasher on the bolthead or something but I think it would be overkill.

-Fred W

[PhilipJCaputo]

I just undid the three bolts that hold that stabalizer bar (the big long one 1 in the diagram) ... which gave me enough room to slip a wrench in there..... but it was a lot more work then I wanted it to be...


EDIT: not bolt 7.... but the three that hold the bar up under the car... I didn't even undo them 100%... just like 80% was enough to do the trick

http://www.realoem.com/bmw/showparts.do?model=HE13&mospid=47406&btnr=31_0045&hg=31&fg=10


http://www.realoem.com/bmw/diagrams/m/g/6.png

[632 Regal]

#1 is the sucker that has to be dropped for me man.

http://www.realoem.com/bmw/showparts.do?model=HE13&mospid=47406&btnr=31_0250&hg=31&fg=05

in addition to the sway bar.

[FWinNH]

#1 is the sucker that has to be dropped for me man.

http://www.realoem.com/bmw/showparts.do?model=HE13&mospid=47406&btnr=31_0250&hg=31&fg=05

in addition to the sway bar.


Yeah, exactly. That's what it seems like on mine, though I haven't done it yet. Mostly because I wasn't able to crack bolt #13 in that diagram. I need to get a better (6 point) socket and a heftier 1/2" breaker bar. My old 1/2" bar is tired (loose in the pivot) and I was afraid to go at it with full force with that and only a 12 point socket.

[632 Regal]

drop it and loosen the nut side, the bolt side was real tight on mine.

[charlie]

this worked for me- grinding down a crapsman wrench


proto, some matco, sears craftsmen professional etc they will have nice thin strong walls on the box end that will slip over the available clearance... If you only have the regular craftsmen with the clunky thick walls then it won't fit. This is the modification that bmw shows to do to a 22mm open end wrench to get it to fit or you can do like George Mann did on his e32 and drop the sway bar on both sides to get roomhttp://www.bimmernut.com/%7Ebillr/images/22mmmodify.jpg