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DIY: Thrust arm bushing and ball joint replacement

28K views 175 replies 16 participants last post by  Attacking Mid 
#1 · (Edited)
I changed out the front thrust arm bushings, and ball joints today, so I figured I'd make a DIY for it. I'd been experiencing a clicking up front under change in fore-aft loading (braking, acceleration, direction), and with the subframe bolts tight, figured I'd change out the thrust arm bushings and ball joints. My car has 152k miles of upstate NY winters, so either way, a parts refresh wouldn't hurt. (*full disclosure: the replacement parts did nothing to stop the clicking, but I found the driver's side outer CV boot torn, so I have a new axle shaft on order; I'll replace the transverse control arms at the same time (I've had a spare set collecting dust on the shelf for 5 years).

Tools needed:
-ratchet, breaker bar, torque wrench
-22mm socket
-21 mm socket (13/16" works fine)
-21mm wrench (13/16" wrench works fine)
-T40 Torx socket
-E12 socket
-BFH (I use a 3 lb lump hammer)
-pickle fork
-chisel
-long punch
-sawzall (or hacksaw)

1) Raise front of vehicle, support on jack stands. I used the jack pad under the engine and then put the stands under the subframe, inline with the transverse control arm attachment points. Remove wheels and engine shield. Spray PB Blaster into the ball joint bore in the bottom of the steering knuckle now.
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2) Locate the thrust arm; it runs fore-aft from the steering knuckle forward to the subframe. Before working on it, remove the two 8mm screws and the upper 10mm nut that hold the plastic lower shield in place; you'll need it free in order to wrestle the bushing's bolt out. The bolt and nut are 21mm (13/16") and the lock nut that holds the arm to the ball joint is 22mm. Brake torque on the TA nut/bolt; I had to shock the wrench with the lump hammer to break it free. Remove the nut but leave the bolt in place.
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3) Next, move to the ball joint. I used a pneumatic impact gun to shock the 22mm ball joint nut loose and remove it. If you don't have one, you'll need to use a 22mm box wrench on the nut and the T40 socket to hold the ball joint stud in order to remove the lock-nut. Remove the nut. Using the pickle fork* and the BFH, separate the arm from the ball joint. (If you are saving the ball joint, use a ball joint press instead; the pickle fork will destroy the ball joint). Swing down the arm, and remove the bolt. My socket shown below looks in rough shape, because I modified it years ago by grinding flats on opposite sides in order to hold it with an open end wrench to do the above job, as I don't have a 22mm box wrench. T40 fits inside the 3/8" square drive hole.
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4) Using the E12 socket, remove the 2 bolts per ball joint that hold them. Now be prepared for a long time of beating metal. Alternating between hammering a chisel between the ball joint and the steering knuckle from the bottom, and hammering a long punch onto the top of the ball joint through the ball joint bore from above (where you sprayed the rust penetrant earlier), keep working until the ball joint gets freed
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5) I'm cheap, so I chose to save something like $150 by just replacing the bushings. THE BUSHINGS MUST BE CLOCKED IN THE ARMS A SPECIFIC WAY. Mark the arm and bushing with a sharpie and then transcribe the mark to the new bushing. If you forget to do this, notice that the bolt carrier is shaped like a triangle, with a key way at the apex. The triangle aligns with the direction of the thrust arm, with the keyway pointing away from the thrust arm.
I unfortunately didn't have an adapter perfectly the same diameter as the bushing to press it out of the arm, so I went old-school and dirty:
-using the press and a socket, I pressed the rubber bushing out of its sleeve (a bunch of fluid came out in the process).
Room Machine

-Using a piece of heavy duty square stock, I then pressed the sleeve down flush to the thrust arm.
-I then secured the arm in a vice, and CAREFULLY cut the bushing sleeve with a sawzall (a hacksaw blade would work too, and be safer) lengthwise all the way through, stopping before cutting into the thrust arm. Then using a chisel, I folded the sleeve so it would fall out. On the second one, I used the chisel and a hammer to drive the sleeve out without folding it, as I'd realized it would work great to remove bushings in the future without going through the above steps. The new bushing easily pressed in (after a coating of grease on the sleeve), as it is wider than the thrust arm, so no adapter needed. Triple check the bushing's clocking.
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6) Installation is the reverse of the removal.

Tips:
DO NOT FULLY TIGHTEN THE BUSHING BOLT/NUT UNTIL THE VEHICLE IS ON THE GROUND. I jacked it up high enough to put 6x6 cribbing beneath the tires so that I could get both suspension compression, as well as space beneath the car to swing the wrench.
-Clean out the ball joint bores with a wire brush and sandpaper before installing the new joints.
-I used Motorcraft nickel antisieze lathered liberally all over the ball joint cap and stud prior to installation.
-I torqued the ball joint bolts (replacements were T40 IIRC) to 45 ft-lbs
-I torqued the lock nut to 50 ft-lbs
-The best I could find for the specs on the bushing nut/bolt is 50 lb-fts +90* torque angle, which implies the bolts are stretch and one time use. I didn't have replacements, so I simply tightened the nuts until the torque felt about the same as that needed to remove them. As I have to get back under there for the axle and transverse arms, I'll most likely replace the bolts with grade 8 at that time.
 
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#2 ·
Nice write up. When I did this, I couldn't get the lower ball joints out for love nor money. I finally was able to free them up by using an air chisel. If you can impact them on the outer metal ring rather than directly on top of the ball joint, it seems to work better.
 
#3 ·
Yeah, my driver's side was a bear. Chisel between the plate and knuckle, punch on the plate now that it's been raised to twist the ball joint in the bore and break the rust, punch from above. I had to make a few different length punches from 5/8" round stock, and repeated drives with the BFH eventually resulted in the sweet sound of the old joint slamming the ground. In hindsight, I doubt I needed to replace any of the above, as they all had life left, but at 150k who knows how much life. If the ball joints weren't in such close proximity to the CV boots I would have taken the MAP torch to them from the beginning, but I didn't want to damage the boots. It turns out, one is damaged, and may be the cause of my symptoms all along.
 
#4 ·
FYI, Advance Auto sells brand new front axles, fully assembled, for under $60. Ordered online for the 20% discount coupled with a $5 coupon, free shipping to my door plus tax, my nice shiny $47.56 axle and CV joints just arrived. Is it OEM quality? Not for a 6th of the price. It seems decent quality though, (I’ll see how it holds up) and importantly (to me) isn’t a reman. And with the lifetime warranty it’ll be the last one axle I’ll ever have to buy, even if it fails... an exchange at the store down the road is much easier than shipping back and days lost...axle’s swapped in an afternoon and wheels back turning.


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#5 ·
Thank you for posting the DIY. I'm having a hard time getting the ball joint out -- what a PITA!

I removed the driver's side, front forward control arm and the bushing is definitely shot. I pounded on the ball joint for hours, but can't get it out. I soaked it with penetrating oil and will try again tomorrow.

Can any of you that posted go into more detail of how you got the ball joint out? I'm considering taking the whole knuckle off to press it out.

Here's a few shots of my progress...

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#7 ·
Thank you for posting the DIY. I'm having a hard time getting the ball joint out -- what a PITA!

I removed the driver's side, front forward control arm and the bushing is definitely shot. I pounded on the ball joint for hours, but can't get it out. I soaked it with penetrating oil and will try again tomorrow.

Can any of you that posted go into more detail of how you got the ball joint out? I'm considering taking the whole knuckle off to press it out.

Here's a few shots of my progress...

View attachment 845339

View attachment 845341

View attachment 845343
I had a terrible time as well removing the ball joint. I wound up buying a air impact hammer and driving it out from the top. It seemed like you had to try to hit the top of the joint on the edge where the sleeve is rather than the top center on the cap that covers the ball. It still took me a lot of hammering. Once it started to move, it popped right out.
 
#8 · (Edited)
I kept at it with swaps between blows with the BFH on a chisel between the knuckle and the ball joint flange, and blows from above with a long rod. Now that the flange is all pealed up, hammer the chisel along the sides of the flange (90* from the bolts) at a slight angle to keep the chisel from walking out. A long chisel is easier to control (I have one that is about a foot long; if you have a bench grinder, you can make one from solid steel round stock). As Tim stated, once movement started, it popped right out. The axle does get in the way of direct blows, so you could always pop the strut, pull the axle from the hub, move it to the side, reattach the strut and achieve a better hammer angle, slightly less work than removing the entire knuckle.

When you put the new ones in, liberally coat them with antiseize; I prefer Nickel for most applications. Pick up a can from your nearest Ford dealer or order from Amazon. I don't like Aluminum antiseize for areas exposed to the weather as it tends to seize (aluminum + steel).

Heat can also be your friend... first on the ball joint from above to burn up any rust, then focused on the knuckle to get it to expand. Just be really careful you don't hit any rubber with the torch.

Are you replacing just the TA bushings or the entire arm?
 
#10 · (Edited)
This ball joint wants to stay with the X3, and is doing it's best. I purchased an air hammer today and went to work. The top of the ball joint is now obliterated and I focused on the top outer edges. I tore a CV boot in the process. It's small enough to fix with a bike tire patch kit.

I went to work on the bottom and moved it ~2mm farther out than yesterday. I finally hammered in a bit and tried to use a second floor jack to push the bit up and use it as a lever to pull it out the ball joint. It lifted up the X3 off the ground until the bit broke.

I'm out of air hammer bits now. The air hammer and BFH isn't working.

[Edit] Don't use MAP gas (heat) as someone else suggested unless you want to buy another control arm... [/Edit]

Progress...it did move more.

Fuel line Auto part Pipe
 
#12 ·
This ball joint wants to stay with the X3, and is doing it's best. I purchased an air hammer today and went to work. The top of the ball joint is now obliterated and I focused on the top outer edges. I tore a CV boot in the process. It's small enough to fix with a bike tire patch kit.

I went to work on the bottom and moved it ~2mm farther out than yesterday. I finally hammered in a bit and tried to use a second floor jack to push the bit up and use it as a lever to pull it out the ball joint. It lifted up the X3 off the ground until the bit broke.

I'm out of air hammer bits now. The air hammer and BFH isn't working.

[Edit] Don't use MAP gas (heat) as someone else suggested unless you want to buy another control arm... [/Edit]

Progress...it did move more.

View attachment 845469
What happened to the CA due to heat? Heat must always be used cautiously.

I forgot to mention earlier with the blows with the BFG: have a block of wood under the knuckle, with vehicle weight on it, so that all force is transferred to the ball joint, and not being absorbed by the strut.
 
#13 ·
On mine the only way I could get it out was by taking the whole knuckle off and banging it out from the top, straight down, with a piece of pipe and a 2lb mini sledge hammer. Popped out with two blows. Mine was fused in with 10 years of snow and salt. Joys of living in the rust belt.
 
#14 · (Edited)
Ball joint
I ended up repositioning the knuckle to get the ball joint out. I pulled the brake caliper aside and removed the rotor. I disconnected the tie rod end, rear control arm and separated the knuckle from the strut.

This gave me enough movement to really hammer on the top of the ball joint more directly. I used a jack to support the knuckle when it was free and did not remove the CV.

A few direct hits with a BiggerFH and the ball joint finally came out.

Front Control Arm Bushing
I used a piece of pipe and a lathe to create enough room for the control arm pushing to be pressed out. I set the control arm on this piece of pipe and used a large socket the was large enough to catch the metal edge of the busing, but small enough to pass through the control arm. A 50k pound press did the rest of the work.
 
#21 · (Edited)
No, it's not. But like anything else, you need the proper tools. If you're careful, the pickle fork will work just fine. My ball joints came out intact even with using the fork.

https://www.autozone.com/loan-a-too...3-pcs-ball-joint-u-joint-press-set/449947_0_0

Or an acceptable equivalent. Free loaner from Autozone.

With 200k on them, there's no way in hell I'd be under there replacing parts and NOT replace the ball joints.
 
#22 · (Edited)
As luck would have it, the girl down the block brought her E83 over to ask about the noises from the front end, so I took the opportunity to add to my thread with things I'd forgotten to mention, or didn't apply. Apparently, she'd had a local shop replace some parts last Fall, and all was well, for a while, but the noises came back. So I pulled it into the shop, and found the thrust bushings installed backwards. I know exactly what happened, too: common thought would want to have the thick part of the bushing installed on the arm line, to stop compression. However, due to its placement, the bushing must resist tension and not compression, and must be installed at the front of it, as the steering knuckle is unsprung. There are two marks, a line and an arrow, but it is the arrow that must align with the TA mark, not the line.

Here is the old bushing, installed 180* out. Note the thick rubber in the bushing set to prevent compression, but nothing to resist tension (the actual force).
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Once the arm was off, into the press it went. You need a PRECISE "pusher", as too large and it won't go through the TA, and too small it'll cut through the rubber bushing spewing fluid everywhere. I used an old bushing sleeve I had (that I'd pressed the bushing out of) with a zip-tie to keep it from spreading. You WON'T be able to use a 2.5" exhaust pipe as the metal of the sleeve is much tougher; exhaust piping will fold right over under the press.
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If you have a front crank shaft seal puller/pusher, you can use its press as well.
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New one pressed in.
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New bushing installed. Note its clocking.
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Old bushing. Note the rubbing in the bushing where it was compressing under tension, causing the squeaks that she noted.
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Total time took me less than an hour from lifting the car to torquing the lug bolts. I took out both TAs at once. Once the ball joint nuts were removed with the impact (if you care about your sanity, don't attempt this job without an impact), a gentle WHAP on the end of the arm with a hammer dropped the arms right off the ball joint without issue. Note: they were greased during the job last fall and weren't seized like a normal 130k mile car. The ball joint nuts are locking, and are *supposed* to be replaced. This is because the nylon locker wears out; these however still had sufficient nylon, so I reused them. I also applied BLUE Loctite to the nut threads, zipped them on with the impact, and torqued to 65 ft-lbs* (the figure given in my E46 manual, I don't have one for the E83). I also used the blue Loctite on the TA-subframe nuts, which the E46 doesn't say to replace. They're ferrous, and large, so F-it. Torqued them to 50 ft-lbs with an additional 45-60* (what felt proper). Note: do NOT use RED Loctite unless you feel like hitting the parts with a torch in the future to melt the Loctite out, or you may snap a bolt, even a big one. $80 and a litre of Krakken later, everyone's happy. :thumbup:
 
#151 ·
They're ferrous, and large, so F-it.
Hahaha I recently finished doing a huge amount of work on my X3 (clutch/flywheel, xfer case, oil pan gasket) and came to this very conclusion multiple times. I always used new aluminum bolts and new flywheel and pressure plate bolts but the manual calls for almost every single fastener to be replaced. Does anyone really replace the stiffening plate bolts every single time they take that out?!
 
#23 ·
Sadly, RockAuto screwed me on this job, as the control arms I purchased were incompatible with the OEM ball joints. :mad:

Old and new controls arms are shown below, side by side - the difference (problem) is obvious.
Not sure what to do at this point, perhaps I need to just press in new thrust bushings into the original control arms..

 

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#24 · (Edited)
Return them, they're wrong. Although, if their length is the same, and the angle between the ball joint and and the bushing end is the same, just use the updated ones with the updated bushings. I highly doubt the knuckle and subframe attachment points changed, but BMW did adjust bushings due to complaints of truck-like ride in the pre-LCI models. Replace the ball joints (which should be done anyway) with a newer style, as long as the knuckle bore is the same. I'd prefer a bigger, more substantial thrust arm and bushing, personally.
 
#26 ·
So whats worthy upfront for suspension refresh not including the Struts and Strut Mounts.

I see the E83 has 2 ball joints and 2 sets of bushings on each side. What are some of the symptoms of these bad boys going? Worth it to buy complete arms or just the bushings and have them pressed in? It seems as tho one of the ball joints can't be purchased and is part of the wishbone arm?
 

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#27 · (Edited)
I had a subtle clunking during weight transfer, but not really over bumps. Upon inspection I noticed some oil on the bushing itself. I replaced #9/10 (the TA bushing as seen in this thread). Replacing the entire arm is definitely easier, it's a simple unbolt-rebolt, but the TAs are considerably more expensive than the bushings alone. I think I used Rein on my car (could have been someone else's) and they were either $50 each or the set... I'm sure I mentioned somewhere in here. I also replaced the ball joint #18 (which goes in hole #16 in the TA); mine were perfectly fine, but I did because I was there and didn't want to go back. In addition, I did the sway bar links. You'll need new axle nuts, not to mention some way of torquing to the 310 ft-lbs they require (a 1/2" breaker bar and pipe won't work; I've snapped 2 doing front end jobs recently). I was completely mistaken on the 50 ft lbs mentioned earlier; no idea where I got that figure from, but all specs I've seen show the 310 ft lb number.

The #16 joint in the lateral arm isn't replaceable (at least easily replaceable) and comes complete with the arm. I bought a set of Reins like 50k miles ago on sale for $17 from ECS and still have them on the shelf, but I haven't had to put them yet though. They came complete with bushing #13.
 

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#28 ·
Yea I get a clunk every now and then too.. I checked all the subframe bolts and all is kosher. The car feels solid though so makes me wonder if it’s really one of these or what.

310ft/lbs wow that’s a fair bit what’s that for? The bushing bolt or ball joint side?


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#29 · (Edited)
Yea I get a clunk every now and then too.. I checked all the subframe bolts and all is kosher. The car feels solid though so makes me wonder if it's really one of these or what.

310ft/lbs wow that's a fair bit what's that for? The bushing bolt or ball joint side?

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Axle nut. It's a very shallow nut requiring a very large/heavy socket, so any torque wants to twist the socket off. I estimated by going to max on my 250 ft lb torque wrench, then setting my impact to 1/4 ft and going until it stopped.
 
#35 ·
Duke what's your opinion is this too much play for the bushing? 153k miles on the vehicle. Hear pops and stuff now and then upfront. Overall car feels solid tho.

Was changing over to my winter tires today and figured I take a peek. The ball joints look and seem to be good but obviously those are harder to check without unbolting the arm.

https://youtu.be/yuqOF_BeCY0

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#38 · (Edited)
Something about the balljoints for the pre-LCI or pre 06 cars not being available or something like that. The later cars have longer studs on the ball joints and correspondingly thicker arms where they attach to the ball joint. Mines an 08 and I had no problem ordering bushings and ball joints, same for the neighbor when I did hers soon thereafter. As long as you have a press, the bushings are stupid easy to replace. Not counting the ball joints, it’s maybe an hour job to replace the bushings. Just make sure they’re clocked correctly as shown in the picture earlier in this thread, there are markings on the arms to align with the marks on the bushings (something I noticed AFTER measuring and marking the bushings and arms lol).


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#39 ·
Something about the balljoints for the pre-LCI or pre 06 cars not being available or something like that. The later cars have longer studs on the ball joints and correspondingly thicker arms where they attach to the ball joint. Mines an 08 and I had no problem ordering bushings and ball joints, same for the neighbor when I did hers soon thereafter. As long as you have a press, the bushings are stupid easy to replace. Not counting the ball joints, it's maybe an hour job to replace the bushings. Just make sure they're clocked correctly as shown in the picture earlier in this thread, there are markings on the arms to align with the marks on the bushings (something I noticed AFTER measuring and marking the bushings and arms lol).

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I don't have a press.. not sure I can complete this task without one.

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#41 ·
I got it apart without a press , then called my friend who borrowed it to get it back for reassembly. I did the tension arm bushing too, and killed the first one pressing it on with poor workmanship. I'll send it back to FCP with apologies for my Hackery, and stipulate to warranty.

You won't get a wheel bearing out from a Northeast car without a press

and felt like playing with 220v glue.
:rofl:
 
#42 ·
I got it apart without a press , then called my friend who borrowed it to get it back for reassembly. I did the tension arm bushing too, and killed the first one pressing it on with poor workmanship. I'll send it back to FCP with apologies for my Hackery, and stipulate to warranty.

You won't get a wheel bearing out from a Northeast car without a press

:rofl:
So you really need a press to do the thrust arm bushing ?

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#43 ·
Take some old angle iron, weld a rectangle large enough to fit your bottle jack in it and BOOM! Instant press.

No NE shop should NOT have a press. Sounds like you need to do some tool shopping first... check kijiji, CL for a used one. Do you guys have Harbor Freight up there?


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#44 ·
Take some old angle iron, weld a rectangle large enough to fit your bottle jack in it and BOOM! Instant press.

No NE shop should NOT have a press. Sounds like you need to do some tool shopping first... check kijiji, CL for a used one. Do you guys have Harbor Freight up there?

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And what would support the under end to press against?

We have princess auto which is equivalent to harbour freight same tools basically just different branding. I've checked my local classifieds and princess auto carries a press but it's like 300$

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#45 · (Edited)
You’d have to get creative with the design and adapters to get the size of the frame right, but all my 20 ton ship press is is a big rectangle with a bottle jack. The jack and arm would both fit inside the frame you glued together. I built a a small portable one years ago for random jobs.

I mean you could get a set of bushings for under $50 and the press for $300, or buy a complete set of thrust arms for a lot more than just the bushings and not have the press for future jobs. I picked up my 20 ton press for $130 new, and found on CL a tube bender, metal brake, and floor mount drill press for $20 for the set. Check classifieds, or any shops that are going out of business.


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