thrust arm bushing bolt - problems with 540i

[bywayofpdx]

I'll get right to it: when doing my thrust arms, there seems to be an additional cross member piece preventing me from getting to the bushing bolt. It's actually connecting the sway bar to the frame, I think. It wasn't on any of the DIY or help threads I read (and I read a ton of them). Or maybe it was and I misunderstood.

Is this a piece unique to the 540? I attached pictures. I found one site where someone seems to address the issue:

http://www.nmia.com/~dgnrg/page_26.htm

Has anyone else run into this on their 540? I cannot get that nut to budge for the life of me! I soaked it in PB blaster and then went at it with a breaker bar and hammer. I'm not even sure I want to be loosening it, though, since I have no idea what it should be torqued backed to.

Another issue I had (albeit a minor one): The nut on my bushing bolt was 21 mm. Every other site said this nut was 22 mm. Anyone else?

Any suggestions? I'm about to throw in the towel and run crying to my mechanic.

Here are the pictures:

https://www.flickr.com/photos/joelharm/13654427864/

https://www.flickr.com/photos/joelharm/13654080905/

[e24mpwr]

to those who will comment - yes the OP has been notified the dog is huge.

[kalevera]

All E34 (with recirculating ball steering) and E32 have it.

The bolt sometimes gets corroded in the frame rail and member but I've never had one of those break on me (the subframe bolts are another story). The bottom of your car is CLEAN so it should be no problem getting it out, just put more effort on it

You might need a good impact wrench to remove it, that or a really long (read - 3 foot) breaker bar.

I don't put them to any particular torque spec going back in, just make sure they're tight.



I would help you if I was there, but I'm not. Sorry

[Layne]

You need to remove the swaybar and brackets and reinstall them when you're done.

[Binjammin]

to those who will comment - yes the OP has been notified the dog is huge.

Wow, so huge, much big, very doge


All E34 (with recirculating ball steering) and E32 have it.

The bolt sometimes gets corroded in the frame rail and member but I've never had one of those break on me (the subframe bolts are another story). The bottom of your car is CLEAN so it should be no problem getting it out, just put more effort on it

You might need a good impact wrench to remove it, that or a really long (read - 3 foot) breaker bar.

I don't put them to any particular torque spec going back in, just make sure they're tight.



I would help you if I was there, but I'm not. Sorry


I forget, do the frame horns have plastic plugs for the bracket bolts like they do for the subframe bolts? If there are access plugs, throwing a little penetrating oil in them couldn't hurt too.

[K Fox]

I forget, do the frame horns have plastic plugs for the bracket bolts like they do for the subframe bolts? If there are access plugs, throwing a little penetrating oil in them couldn't hurt too.

I believe they do (as I remember reading somewhere in here that this is a big way those eventually get corroded), but access with an M60 above it isn't all that fun.

That said, OP - one thing I've tried successfully was wedging a screwdriver under the flat side of that nut and turning the bolt - when you try pay attention to which way the nut tried to turn, and wedge the screwdriver in so that it isn't being pushed out the bottom. This will hold the nut still while you loosen the thrust arm bolt and you should be able to drop it that way. Of course, you're lucky - when I attempted it myself, I found out that mine was installed backwards - the bolt head was the part that was 'inaccessible' - so even with it completely loose, I still couldn't get the bolt out - I had to drop the little frame too, and that stripped out completely on me. Good thing it was on a junkyard car...but mine matched the orientation of the bolt - yours looks like it was installed so that your thrust arms are easier to remove. I'm jealous.

Fox (dat avatar...:rofl)

[bywayofpdx]

Yeah, sorry about my dog, guys. Setting up a profile with the app linked my Google profile pic.

Sounds like the recommendation on the sway bar is the old standby: time and effort. I'll look into an impact wrench. Anyone have something they like better than PB Blaster?

But what's gonna happen when I need to torque that bushing bolt? Seems like I'd need to put the car under load, torque the bushing bolt, and THEN reattach the sway bar.

Fox - if I'm reading you right, you think I may not even have to take off the sway bar bracket (using the screwdriver like you suggested)?

Thanks for the help fellas. Learning as I go here.

[5mall5nail5]

FWIW I have worked on about 3 or 4 E34s where I simply could not remove that sway bar bracket bolt. I am talking IR thundergun impact at like 180 psi, 4' long breaker bar, etc. I ended up modifying a 22mm or whatever wrench it is to fit in there on that nut.

[K Fox]

Fox - if I'm reading you right, you think I may not even have to take off the sway bar bracket (using the screwdriver like you suggested)?

Yeah, that's the general idea. If you wedge the nut tight and can loosen the bolt, you can then pull the bolt out the front and drop the TA without removing that sway bar brace/bracket. As long as the bolt was fed in from the front - which it looks like it was in your pics. For posterity, both of my 540's had the bolt fed in from the rear - meaning whenever it was last done they dropped the whole thing and assembled in on the ground, then put the whole assembly back in afterward. But not all cars are put together that way, and if I remember correctly, the Bentley calls for the bolt to go in from the front of the car.

Fox

[zubbie]

weird. Just completed this and had no problem getting a open ended box wrench in there from underneath on my 535. Did not remove the sway bar. Car was sitting on ramps at the time when the UCA's were torqued.

Of interest is that the bolt is easily accessed from the other side (wheel well) with the wheel off. If you wanted to you could use a floor jack under the strut to load the suspension, access the bolt from the wheel well with an open ended wrench and torque to spec.

[ross1]

weird. Just completed this and had no problem getting a open ended box wrench in there from underneath on my 535. Did not remove the sway bar. Car was sitting on ramps at the time when the UCA's were torqued.

Of interest is that the bolt is easily accessed from the other side (wheel well) with the wheel off. If you wanted to you could use a floor jack under the strut to load the suspension, access the bolt from the wheel well with an open ended wrench and torque to spec.

Same here, I can't remember if the V-8s have a different bracket there but I always manage to squeeze a(22mm) box wrench in there through the wheel well.

[Binjammin]

Same here, I can't remember if the V-8s have a different bracket there but I always manage to squeeze a(22mm) box wrench in there through the wheel well.

They dont, you can.

[Layne]

Seems like I'd need to put the car under load, torque the bushing bolt, and THEN reattach the sway bar.

That's exactly it. It's a pain in the butt, but I'm used to it after doing the job a dozen times. This is also why you buy the best parts available.

The swaybar can just lay on the ground with the links still attached.

[Binjammin]

That's exactly it. It's a pain in the butt, but I'm used to it after doing the job a dozen times. This is also why you buy the best parts available.

The swaybar can just lay on the ground with the links still attached.

Listen, Texas boy... I dont know if the sun has wonked you out or what, but up here we have a little thing called rust...

:rofl

Seriously though, Jon's right about those bolts getting stuck. I've had them gall threads on the way out too. They can be surprisingly difficult.

[BMW IDFR]

always use wd-40 the day before you work.

I assume EVERYTHING on my car is rusted, so a nice soak-in is always in order.

[K Fox]

always use wd-40 the day before you work.

I assume EVERYTHING on my car is rusted, so a nice soak-in is always in order.

WD-40??!? I'm gonna save you some time and effort the next time you work on your car - go buy a can of P'Blaster. It's scary how effective it is, and once I found it I was finally unafraid of certain repairs I had previously been unwilling to attempt. Blaster is simply cool...buy one and see.

Fox

[Binjammin]

WD-40??!? I'm gonna save you some time and effort the next time you work on your car - go buy a can of P'Blaster. It's scary how effective it is, and once I found it I was finally unafraid of certain repairs I had previously been unwilling to attempt. Blaster is simply cool...buy one and see.

Fox

Amen, WD40 is not a lubricant.

[m735is]

Ditto on the PB Blaster. I spray it in the frame holes to get to the threads of those sway bar bracket bolts days in advance. Plus a little heat to help things along. Anti seize upon installation for the next time too.
On my e32 the bolt was put in from the back, what a PITA. I switched it around when I put it back together. All other cars have the bolt in from the front.
I also ground down an open end wrench to jam in to hold the nut still (just like on Norm's site).
I do slightly remember that the e32 had the bolt that goes up into the frame was really tight. I just put a longer breaker bar on eventually got it out. Now that the bushing bolt is in from the front, I haven't had to touch the bolt you're talking about when swapping out UCA's.
Looks like you don't have to deal with rust, so that bolt just be in there TIGHT!

[Layne]

but up here we have a little thing called rust...

You mean your swaybar bolts don't still have their black oxide coating? That must suck for you. :D

[Binjammin]

You mean your swaybar bolts don't still have their black oxide coating? That must suck for you. :D

Everything here is covered in ferrous oxide :(

[ross1]

You mean your swaybar bolts don't still have their black oxide coating? That must suck for you. :D
Nobody likes an a**hole!

[Old525i]

I used a 7/8" closed wrench to get to the 22 mm bolt. No problems at all.

[Sankekur]

but I always manage to squeeze a(22mm) box wrench in there through the wheel well.

This is what worked for me.




OP also remember when tightening these bolts that it should be done under load.

[bywayofpdx]

i was able to get a little more clearance when i lifted the car a little higher but it's still too tight of a fit for my 22 mm combo wrench (either end).

i'm looking around for something that can squeeze in there because i REALLY don't want to remove those sway bars. i'm thinking a crowsfoot might do the trick. or maybe a flare wrench.

i may have to order online but since i'm not in a hurry to get the car moving again, i can wait for shipping. plus sears can ship to store pretty quickly

[zubbie]

go to your local cheap tool store and buy a 22 mm wrench, grind it down to fit in there and call it a day

Harbor freight has a whole set for $20 http://www.harborfreight.com/14-piece-metric-combination-wrench-set-68807.html

[teutonik]

I just did this job a couple of weeks ago. I too thought that I would have to remove the subframe in order to remove the thrust arm bolts, BUT it turns out that the closed end of a wrench fits fine and the bolt end is easy to get to if the car is high enough. (On a lift this is a piece of cake.) I made the mistake of removing the subframe and breaking one of the bolts - rusted in the subframe. Resorted to tacking/welding a nut in order to pull it off the remaining stud. Also found that the subframe bolt was on a 2 week backorder at the dealer.

[5mall5nail5]

You just have to rotate the bolt sometimes to fit the box end in

[Binjammin]

You just have to rotate the bolt sometimes to fit the box end in

That's what she said. :shifty

[Layne]

This is weird, but I had both my car and my friends M5 on a lift this weekend.... The clearance is different. You could get a wrench on the m5 nut (presumably all 6 cyls), but not a chance in heck on the V8. My old 740 was the same. Maybe the bushing-holding cross member thing is different? I haven't looked up the part numbers yet.

[zubbie]

This is weird, but I had both my car and my friends M5 on a lift this weekend.... The clearance is different. You could get a wrench on the m5 nut (presumably all 6 cyls), but not a chance in heck on the V8. My old 740 was the same. Maybe the bushing-holding cross member thing is different? I haven't looked up the part numbers yet.

I looked up the part numbers.

Bolts

M60: 07 11 9 914 854 M14X1,5X130

All 6 cylinderE34's (including M's) : 07119900483 M14X1,5X138

Cross Members


M60: 31 12 1 141 621
all sixes: 31 12 1 133 682

so it looks like the cross members and bolts are actually different for M60's

[Binjammin]

I looked up the part numbers.

Bolts

M60: 07 11 9 914 854 M14X1,5X130

All 6 cylinderE34's (including M's) : 07119900483 M14X1,5X138

Cross Members


M60: 31 12 1 141 621
all sixes: 31 12 1 133 682

so it looks like the cross members and bolts are actually different for M60's

Allow me to further complicate things:

Part number 31121138244 is from a late m50 car. The difference?

http://img482.imageshack.us/img482/9313/img2168medium6ok.jpg

See the two tabs on the bar? They're for the boomerang mount. The kicker? It uses bolt part number 07119914854, which is the same as an m60. I'd say it looks like around 92 with the update to the e34 they changed the front suspension slightly, so late cars (m50, m60) have the updated bolt and the only difference between 6 cylinder and 8 cylinder bars is the tabs for the boomerang mount.

[Layne]

What the heck is a boomerang mount? Never seen those tabs... but I never looked under and M50 car.


So if the bolts are 8mm different in length, it seems logical that the 6cyl crossmember is 8mm thicker. Sounds about consistent with what I saw.

[Binjammin]

What the heck is a boomerang mount? Never seen those tabs... but I never looked under and M50 car.


So if the bolts are 8mm different in length, it seems logical that the 6cyl crossmember is 8mm thicker. Sounds about consistent with what I saw.

Looks like this:

http://c1552172.r72.cf0.rackcdn.com/206375_x600.jpg

There are mounts that go to each leg on the mount, and the cross member. The other end goes to the tranny. There's still the traditional tranny crossmember in the back as well too.