Thrust Arm Bush Replacement Procedure!

[e34.535i.sport]

As you probably noticed I changed my thrust bushes to the powerflex variety recently hence: http://www.bimmernut.com/forum/showthread.php?t=39445 . This procedure will apply to changing them for other 'normal' bushes with the small difference of having to press the new bushes in. I would NOT want to do this lets just put it that way!

Procedure

I'll have to do this over a few posts on this thread as I can only attach four photo's per 'post'... I apolgise if some of the pic's aren't great...

TOOLS
You will need the following tools - some you may not use it all depends on how lucky you are

• 22mm Spanner
• Socket set - inc 10mm 15mm 17mm 19mm 22mm
• Large breaker bar
• Good Ratchet
• Extension for Ratchet
• Balljoint Seperator
• Jack
• Jackstand
• Press - if you can get one
• Jigsaw + lots of blades
• Hammer
• 19mm Spanner
• Peice of strong sturdy wire
• Torque Wrench
• (Maybe a Screwdriver)

REMOVING THE STEERING PLATE
Firstly, I decided that I would remove the whole steering plate with the thrust and control arms attached to it to save buggering the balljoints... It may take longer than just removing the Thrust arm itself but this was the preferred method for me.

Jack the car up and secure with a jackstand. Get all your tools ready and accessible...


Take the two under trays off now if you don't want to be arsing around later (learn from my mistakes! ) - use the 10mm socket on the nuts/bolts.

Sit down and look at the thrust arm pivot bolt... You need to undo the nut but not remove it for now.



Get the 22mm spanner and put it on the nut side. Get the 22mm socket on the bolt side and use the breaker bar on it. It should be moderately tough to crack at first but not too bad. Loosen the nut off but leave it on for now.

Now look at the control arm pivot bolt. You want to loosen the nut off on this but again leave it on for now.



Get the 19mm spanner on one side and the 19mm socket on the other side and undo it - leave the nut on the end.

Now you need to look underneath the bottom of the shock at the steering plate - this thing:



You want to get the 19mm socket and breaker bar and loosen the nuts off enough so that you will be able to use the ratchet to undo them later. Leave them in for now. (There is a good reason for this!!)

CONTINUE TO NEXT POST!

[e34.535i.sport]

Now, after loosening the steering plate nuts turn your attention to the tie rod end... (track rod end): Take the nut off with the 15mm/17mm socket whichever it is...



You will need to remove this balljoint to get the steering plate off the car so get a balljoint seperator or pickle fork and free the tie rod from the plate... I done it like this -



When it pop's out just move it out of the way... Now it gets interesting!!! (*At this mpoint you might want to removethe sway bar link on one end to save the boot getting damaged, up to you but I left it on and it was ok!)

You will need to be aware at this point that once you start removing all the loosened nuts and bolts from before the strut assembly may turn violently as the mount on the top is actually a bearing... So be careful.

Remove the bolt from the thrust arm and put it somewhere safe, do the same with the control arm bolt. now remove the three bolts from underneath, the ones on the steering plate. Keep the strut from turning with your knees if you need to. Now simply get the hammer and bang the steering plate down to free it from the strut... If it hasn't been off for a while you may need to get a screwdriver and pry it away. The plate should come off and you can remove the plate with the two control arms from the car... like so:



Now use the stiff wire to secure the strut to one of the holes where the control arm goes to stop it turning too much.

With the plate off you're almost there, just the easy job of getting the old bush out. (Shudder at the thought of it now LOL!!!). It was a mammoth task for me I'll be honest!

First, I got it in this press and attempted to press it out -



I pressed it that hard that I broke the press!!!! The bush remained unaltered in the arm... You can see what I'm getting at...

CONTINUE TO NEXT POST!

[e34.535i.sport]

PLAN B: CUT THE BASTARD OUT!!! I resorted to my old friend, the JIGSAW:



Get it in the workmate if you have one and cut right through from the centre to the outside of the metal ring... This takes some doing I'll be honest. Wear goggles or something and maybe a mask or something. You WILL need more than one blade unless it's made out of titanium or something! I broke about 5 or six. Keep at it, it will frustrate you. Once you've cut through the edge try to hammer it out. In my case the rubber part came out leaving a single metal ring to come out. I took it into work, got it on a big metal vice and hammered fk out of it and it came out.

You could also try drilling through the rubber in multiple places to get rid of that because it's hard to cut with the saw. Do whatever works!!!!

Once you have it out and you've got over the sheer joy of it put in the two peices of purple powerflex bushes, grease up the metal centre and stuff it in. It should go in nicely... Looks like this once it's in:



The two metal washers go either side of the purple rubbers when you put it back in so don't forget!

REFITTING
When you go to put it back in, it's up to you whatorder you do it. I will tell you what I done anyway...

Firstly I pushed the steering plate back up onto the strut assembly and fitted the three nuts to 'ratchet tight' for the time being... Then got the control arm bush lined up and put the bolt through with the nut/washer on finger tight only.

Next I got the tie rod end and reattached it to the steering plate... I tightened the nut just snug for now, torque it later.

Now do the same with the Thrust bush as you did with the control arm bush but there seemed to be a knack to this with the two metal washers to get on. I put the bolt through the hole a tiny bit and rested one washer on it... Then pushed the arm/bush up with the other washer on the other side and pushed the bolt right through it. It's hard to explain but you'll figure it out anyway when you have it in front of you. It'll end up like this:



Now you should be able to torque the tie rod end up to about 40nm, and the steering plate bolts to around 70nm (I think the haynes says 65nm)...

You need to torque the Thrust arm pivot bolt and the Control arm pivot bolt UNDER LOAD... This means you should wait to fully tighten them until you drive it onto some ramps and while it is sitting at normal ride height.

So bang the wheel back on, torque up the wheel nuts and let her down. Get it on some ramps, get underneath and torque the Control Arm pivot bolt to 75nm (I think) and the Thrust Arm pivot bolt to 130nm (pretty sure!)...

Make sure everything is as it should be and get over to the other side and do it again!!!!!

Here's a pic of underneath with the new bush:



I'm going to reserve comment for now on the results, but it's definitely firmed up the front end and rid me of the annoying 60mph shimmy... I'll report on them fully in a week or two.

I hope this has been of some use, good luck...

[Old Man Pete]

Just a bit worried about your steering plate as Bentley manual says to tighten to 110Nm and to use loctite thread lock. Definately one part of your car you don't want to drop off! Great write up though!
Had to use blow lamp and BFH to get thrust arm ball joint off steering plate on both sides of my car

[e34.535i.sport]

Just a bit worried about your steering plate as Bentley manual says to tighten to 110Nm and to use loctite thread lock. Definately one part of your car you don't want to drop off! Great write up though!

Hey I was going off the Haynes manual but it's vague to say the least!!! Thanks - I'll be tightening them up I think!!!!

[sal_park]

...and that's loctite 270 btw

[sneekens]

Nice write up! How harsh is harsh now that you have POLY bushings in? Or it's not really that bad....?

[e34.535i.sport]

To be honest it is a tad noisier depending on the road surface but nowhere near enough to be a nuisance. I think mine is uqite a harsh ride due to the 18" inch wheels mainly, but it is still comfortable in my eyes... Other people may not like it it's hard to speculate!

The benefits of the bushes far outweigh the small negative issues I would say.

[632 Regal]

nice write up!

[attack eagle]

nice, surprised you didn;t break out the torch and burn out the old bushing so all you have to cut was the outer sleeve to remove it.