Front Lower Control Arm Busing Removal
 

Hi Guys, I need to remove the original rubber front lower control arm bushings. I have some purple powerflex poly bushings on the way. Would have probably gone with original, except the cost is just nuts. As it is, this restoration is moving at the speed of stink.

Anyhow, I looked for posts on doing the lowers, and also on youtube.com. Didn't find it. How does one get these old bushings out? Thanks in advance.

https://cimg6.ibsrv.net/gimg/rennlis...d693364238.jpg

I would think that the people selling the bushings would be able to tell you. I'm curious myself.

Similar bushings on other cars I used a blowtorch to melt them out. I don't recall any of those suspension pieces being aluminum though.

Assuming you are going with the stiffer poly bushings in the rear location too? Be sure to follow the WSM procedure for torquing down those bolts so the suspension settles better. The hanging nose of the 928 will only be worse with stiffer bushings:

Why do I think this is not going to turn out well?

:corn:

Thanks
 

I was thinking the same thing: Melt the rubber out, unless there is a better way. I don't want to mess up the control arm. Gonna replace the front upper and lowers with the powerflex purple which I believe are 30% stiffer than stock. The black poly bushing are another story - 80% stiffer. It's just a street car, so that's overkill. Going to do the rear later. I hear than these newer polyurethane bushings do not squeak like some of the older ones. If it squeaks, I guess I'll just turn up the radio, right?

I think if I take anything else apart on this car (like the rear) I will seriously never get this car back together. Plus, I save to save for every new part so progress is so slow. I just want to get the car moving. It's been 10 years since it was on the road.

We don't mean any ill will, just a lot of iffy opinions of using poly for suspension bushings.

Either way, just pay close attention to the above verbiage in the WSM, that is very important. Most suspension pieces you should physically hold at or close to "resting" before you torque the bolts down. That's a bit tricky with how these arms are designed and if you torque them down too far out of the center position, they may never properly settle.

Also your alignment will be more critical than most since the amount of time and effort it will take to "settle" will be longer than stock. This just reinforces the alignment procedure in the WSM where the shop doing the work sets & measures ride height by pulling down the nose instead of relying some some arbitrary mileage hoping the nose is fully settled.

Why would you do this?

The original bushings... Fronts are made-in-place for the most part, so the rubber flexes but doesn't actually move. I'm not sure how an aftermarket bushing material can be similarly made-in-place. Neither the aluminum control arm nor the aluminum support are ready for a bushing that slips.

In the rear, the bushing is bonded to the control arm and sits in a saddle between a formed section that's part of the crossmember, and the aluminum support. There is no provision for a slipping-style bushing. In fact, the factory recommends that you allow the suspension to settle some, before final tightening of that rear support clamp if the clamp is loose when the car is lifted on the suspension.

I'll be very interested is seeing what is actually supplied, and how the supplier recommends installation. :corn:

This is a huge misconception by..well, not to put a finger on the OP, but..people that buy a car and go off and change it, entirely against the principles that the car was designed under.

928 arm bushings are active SPRING RATE at work. I cant see a poly bushing working the same way.

Not just a dumb universal spacer allowing movement...and this is why aftermarket suppliers are just not stacked up providing these.

the reason there is no info on bushing replacement is .... they are bonded in place .... not replaceable .
928 international has rebuilt units

Just use a press to push the bushings out. That is what I did and no damage at all. If I get time I will post some pictures. Where did you buy the Powerflex bushes?

Don't buy the powerflex bushings! I repeat - don't buy poly bushes. My best man, who is also on here - drnick - did it and within 3yrs they were FUBARed...

It has already been said - the original bushes are part of the spring-shock combo and work very well.

There are two-known sources for replacement - Mark Anderson's rebuilt arms, which by the way are superb, and Rosepassion in France, who would sell you the rubber bushes, but you would have to figure out how to bond it to the arms.

The bushes at both ends are a push fit installation and each end has an inner bush and an outer bush separated by a concentric stainless steel spacer. The installation sequence is listed being critical to success.

I was thinking of going this route when I found my driver side LCA [I was using the earlier longer arm/bracket to get more camber on that side] looked shot [I did a thread on this]. Instead I reverted back to the stock arm recently and was surprised when I managed to get it to 1.7 degrees [previously it was just over 1 degree or so the Hunter said] so no need at the moment.

I was intrigued as to how these bushes work compared to the stock items and I suspect some of the judgements here may be a bit hasty. I figured that the Powerflex design might be intended to allow some slip but more likely the concentric steel spacer locks onto the inner eurethane bush when the assembly is pressed onto the hub and the outer eurethane bush is locked to the inner spacer by the external clamp/bracket. How this impacts overall suspension movement in terms of stiffness remains to be seen but I get the impression this outfit may well know what they are doing if their CV is anything to go by.

Needs someone like Mark K to give them a good shakedown [ assuming his "vacation" is nearly over?].

Alex, Powerflex bushes, the street versions come with a lifetime warranty, the race versions don't. These bushes are three piece designs and have been revised recently. Did Nick's bushes come from Powerflex? I know there was two piece designs around before by other sellers that of course won't last. The discussion I had with Powerflex was that the main reason behind the three piece design is because the arm's spigot is not a machined part as such it's needs an adaptation to a machined surface and this also allows for the variation in bushing stiffness.

As to the bushes forming part of the spring rate, I think we all know they shouldn't be performing that function. I think we all are aware that as our cars have aged various wear parts have changed our car's feel. Some examples are, damper valves, bushes, and seat bases.

The key advantage of these three piece bushes is that there is no settling required. There is little resistance to movement by hand force. As such the arm can track easily and accurately it's designed pathway. This way stitchen is greatly reduced and dampers can be more accurately tuned.

Thanks for the feedback. I am going to tilt some of you guys with what I have to say below. Sorry about that. Just my opinion.

Anyhow, I already bought the lower powerflex bushings so I am basically committed. If I lose a bit of the "built in shock" characteristics of the factory bushings, so be it, I have aftermarket lowering springs and Koni shocks to make up for it. I man who is going to notice it driving on the street?

What I don't understand, and what ticks me off about the 928 is fact that Porsche, and it's supposedly "brilliant" team of engineers intentionally designed a car where the owner is expected to replace an entire a arm (expensive) just because the rubber bushings are worn out. Or, ball joints on the later cars that are not replaceable like most other car manufacturers? Then there is the rear suspension... Even these "interference motors" are nothing short of diabolic. Surely Porsche could have built in deeper valve reliefs in the pistons so they whole top end is not lunched. As for the small loss of power due to lower compression, you would never feel it. Aluminum cam gears that are crap and wear out...even aluminum ball joints...yikes!

I mean who builds a suspension that cannot be lifted off the ground to align the front end without screwing up things? A suspension that needs time to "settle" (if it settles) before the bolts can be torqued? Sorry, but I can only see this as a design flaw. As for the "built in shock" in the a arm bushings: This is just a fortunate side effect (or happenstance) of an otherwise greedy and evil design (ex: rubber bushings vulcanized onto the control arm so they are not rebuildable). If Porsche thought they could get away with making you buy a complete, 1 piece drop in front and rear suspension that was not rebuildable and costs 10k they sure would of.

Where exactly is the FUN in all this when a 928 buyer spends and spends and spends and can still never afford to get their car done? Never even drives it. Craigslist is riddled with old 928 caracasses that the owners cannot afford to fix. Sometimes I feel like I will never get this car done. End of rant.

Your bushes dont look really worn out in your photos..and the upper rear ones go sour, they can be replaced.

Keep in mind how much danger your lower engine block will now be in as well.

Quick question- Is either rubber bushing on the lower control arm pictured in post #1 failed? (ie- is the forward one's rubber separated from the arm or the mounting bracket?)

If not, I'd just run those arms as-is. The rubber on the rear is smooshed a bunch but as long as the rubber's still vulcanized to the arm at both ends, I'd save your money for whatever else is keeping you from enjoying the car.

Wow, that's interesting. That's the opposite effect most other cars have when you go from rubber to poly bushings. Now I'm tempted to try them on my 79... :icon501:

How many other cars have you worked on? This isn't terribly uncommon. I recently updated all the rubber bits on the front of my friends F150 and the box of parts from Ford was new control arms. Could they be rebuilt? Sure, if I have the correct tools. Same with the 928 arms. If you have the knowledge & equipment they can be rebuilt. It's just easier to swap the arms.

I replaced all the rubber bits on my SAAB. After spending several hours at Turbo Todd's shop making custom tools to push out the old bushings, he really questioned why I didn't just buy the rebuilt arms with the bushings already installed.... I didn't have a good answer, he was right. The amount of time we wasted did not make up for the extra cost of all new parts.

Dear Lord, not this BS argument again. Make a list of every car made today that is not interference. Even the Chevy 350 in most GM vehicles are interference. Friend of mine busted up an engine real bad when he lost a timing chain in his ZO6. So maybe there is more to it than a couple simple valve reliefs.

The procedure is detailed in the WSM and is very easy to follow (yes I've done it). I could understand this issue if Porsche never bothered to share with the world how to do it.

See my post above, all suspension bits need to be at level before the bolts should be torqued. Any experienced mechanic knows this.
My Saab has a detailed procedure similar to the 928 when replacing the rear bushings.

Again, work on a few more cars and get back to me. It's very rare on modern day cars to rebuild suspension pieces. Shops order new units with new bushings installed. Yes they can be rebuilt if you know how (most shops do) it's just easier to swap the arms.

So the real complaint is you are not qualified to rebuild them yourself and this is Porsche's design flaw???

Vintage Porsches are not for everyone, that is why God invented Mustangs and Camaros.

Why do you "need" to remove the existing bushes- is it simply because you want to fit the Powerflex items? For sure these things degrade with age but if my experience is anything to go by it takes a really long time.

When you post a query please include your model and year- more often than not it is relevant. The bushing is the same for all model years but 86 and earlier have different arms [FYI]. The older the arm the more likely degradation has ocurred. From what I can of your photo I see no markings on the arm so perhaps that suggests you have the older model?

Either way what prompted you to suspect the arms were shot- not saying there is nothing wrong with them but intrigued as to what drove you to your decision to refurb.

Regarding your original query I removed the front end bushing using a press but for the rear most one I used my dremel to cut through the bush [see pic 1 below]- if it can be removed by a press so much the better but I was "exploring" at the time. I tried to be very careful and I caught the flange face ever so slightly but nothing of consequence. The trick is to know how deep to cut. Fiirst of all one has to cut through the outer rubber layer and then the inner steel layer. Once the steel layer has been completely breached you then tackle the rubber with great care. Where the inner bush sits on the stub of the arm the surface is serrated [see pic]. I cut through the inner rubber until I could see some kind of separation- after that I pried the cut surfaces apart and the bush came away quite easily [to my relief] and no sign of anything bonded just what looked like a press fit.

Now the interesting bit- as you will have seen from the above posts the consensus suggests that these bushes are bonded to the arm- I saw absolutely no evidence to support this front or rear. For sure the rubber is bonded to the inner steel sleeve. Whether or not it was bonded originally and that degraded who knows but I saw no evidence to support this.

As and when you get round to fitting the bushes do keep us posted with pics so we can learn something unless of course you decide not to fit the bushes at this moment in time.

Regarding your "rant" all I can say is welcome to the club! You can buy a 30 year old supercar for peanuts but you cannot run it for such and if that is your want flog the thing and go play with something else. Hopefully you will see the light and come to think like rest of us "nutjobs". It is not uncommon for people to purchase these machines and spend more in the first year of ownership than they paid for it. Buy one that has been properly looked after for top dollar and you will still have bills but way less than with a neglected mongrel.

Rgds

Fred

Glad to see another person open to using non porsche bushings. Personally, I think the powerflex bushings are going to work great. These are supposedly huge in Europe with the BMW crowd. When it's done, I'll bet the thing handles like it's glued to the road. Granted, my 928, in the 6 months I actually got to drive it (so many years ago) handled fantastic. If the head gaskets hadn't blown, I'd probably still be driving it today. The car is indeed a feat of engineering, especially for its time....

Perhaps I was a bit harsh on Porsche and its engineers, but who can afford some of these parts? It's crazy after a while...

I am going powerflex in front (upper and lower) and probably poly bushings from 928 performance in the back, as I don't think powerflex makes them for the rear.

What is the worst thing that can happen? The car rides too rough? The bushings crap out? A front control arm flies off, the car rolls over 10 times then explodes? I been married 27 years. BRING IT ON! ..and if I'm unlucky enough to limp away, I can always beat the car back into shape with as 5 pound sledge and go back to using Porsche bushings... It's a good plan :)

But seriously, our 928's are not exactly skyrocketing in value like the air cooled 911's. Who gives a crap? Experiment on them.

I found them on EBay. I used the purple bushings for the lower control arm. The cheapest eBay seller I found was demonweeksdirect, located in the UK (they all are) . You will need 2 different sets to rebuild the front lower control arms. Part PFF57-701 (frontmost bushing) at about $115 and PFF57-702 (rearmost bushing) at about $112.

I also got the top wishbone bushings come in black. PFF57-704, which were $167 for the 4 bushings. These bushings are not so cheap, so I am hoping that they are really good and durable. With shipping you will pay a little under $400 plus shipping, which is pretty cheap. YOu can also get front and rear sway bar bushings. I did not get them yet. Might use others from 928 Performance, not sure yet.

When I put these in, I will make a video on youtube.com

As a stubborn German, my rabid OCD compels me to replace the old bushings since the whole front end is presently apart. I took it out to upgrade the front cross member to the 83 and later one (newer motor mounts). I don't want to change the bushings, but I am sick. I have no choice. Otherwise, I will not be able to sleep.

Thanks for the reply. No, they are probably reusable. I just don't want to take this thing apart again.

Thanks

No, they don't show how to remove the old ones, just how to reinstall their new bushings.

Used Powerflex bushes in E46 M3. The difference in handling was night and day. The car rode no more harsh than it did previously.

Great to hear! Thanks a lot.

Something to keep in mind is that the car cost about as much as a small house when new. It was the pinnacle of Porsche engineering in it's time. Just because you can get them cheap doesn't change that fact. And the parts price reflects that.

Cayennes are the same way. You can pick up the early ones for next to nothing (compared with sticker price), but parts prices still reflect that sticker price, not what they sell for now.

911 prices seem to be leveling off. Some of the "bubble" seems to have settled down (not exactly 'burst'). 928 values are increasing. But (as is normal for this sort of thing), the ones seeing the most increase are the first and last, and mostly all original, low mile, pristine examples. When and if 928s are going to see rusty shells going for 4 or 5 figures remains to be seen.

Wondering how this went as I'm just about to do the same thing. One of lower control arms is now a two piece unit.

I still honestly don't get this obsession with Polybushes on here. Rose Passion in France sell the front bushes, which are the same bushes that Mark Anderson uses on his rebuild units. Mark Anderson's upper and lower arms are re-furbished by the only company in the World that supplies refurbished Ferrari suspension arms. Should you wish to go for harder rubber, you can - Rose Passion offer rubber bushes, which are 30% harder than stock. Rose Passion ships world wide. The manufacturer has another agent, who sells the bushes on German eBay too and also ships world wide. I have used Rose Passion for the Upper A-arm bushes and the quality is superb. Miles better than the poly rubbish - yes, I also have an E46 M3 and no, it won't see poly anywhere.

Porsche was not stupid when they designed the suspension. My race 928 has hem-joints everywhere and it is more direct and responsive. But it is unbearable on the road. The original rubber bushes have normally lasted 30yrs+. Given that they cost the same as the poly, I would place my fate in the hands of the Porsche guys...

Cost is the primary reason.
After that the "aftermarket" idea that poly bushing are better. I'm not sure what "better" means either.

PowerFlex:
Front Lower Rear = $130
Front Lower Front = $133
$263 covers all four front lower bushings.

928 International Rebuilt Arm is $295 each.
A savings of $327 for the PowerFlex....not counting labor of installation. Considering the labor time to manually swap out the bushings, at the typical labor rate of $100+ per hour at most shops..... The cost savings is artificial IMO.

Even if poly bushings offered any amount of handling upgrade, their longevity is not theory, it's well documented. Poly bushings do not last anywhere near as long as stock rubber.

All I can say is, you can use whatever you want. I'll use whatever I want. My car will not be a daily driver. Maybe once every second weekend. Anderson says his rubber is recast onto the control arm when he really is just pushing on a new bush?

The Solution: These remanufactured Front Lower Swing Arms have been completely rebuilt to spec by degreasing good cores, breaking the old rubber off, bead blasting, and recasting with new rubber directly onto the swing arm journals, just like OEM.

The very fact you are asking on here means you don't know. I have done it, thus I think I know a bit more than you on THAT exact topic. I also know first hand by virtue of swapping a set of hem joints and a custom rod to give me a shorter arm for more camber in my racer, as well as installing a set of genuine bushes on my Street car.

What Anderson's description says and what the reality is are two different things. I have spoken to the company which supplies the rebuild arms to Mark Anderson. Nothing is cast in situ. If it was, the company would not be selling the tools that are used to press the bushes into the arms as a package either.

It appears that you want to hear, what you want to hear. I have contributed my piece of advise. Whether you take it or not is a moot point.

Also, it pays to be nicer when you are asking for information from those of us, who have done it before...

Where is this description you mention? Our web site says "These rebuilt arms come complete with new rubber and look like new"
And the tools you mention sound like the ones they provide to install the upper bushings. http://shop.928intl.com/A-Arm-Bushin...28-341-990-20/

Mark, it was the previous poster that made the statement about your website and the rebuild method. Read the post above my reply.

You need to relax mate. You certainly ain't the 928 God nor the 928 Suspension God either. I don't think I asked for anybodies advice, I asked how this went.

Interesting.

I ordered the powerflex items for the lower arms. They came and are of much better quality and density than the previous ones from a guy in Australia (which dissolved on the car). These powerflex actually seem like they will fit properly.

High hopes. Realistic expectations.

https://cimg7.ibsrv.net/gimg/rennlis...e0d01153e9.jpg
https://cimg2.ibsrv.net/gimg/rennlis...f749ddbd99.jpg
https://cimg3.ibsrv.net/gimg/rennlis...e9f1f71ae4.jpg
I modified my lower rubber bushings years ago on my 1978 Track car. The goal was to have a free moving suspension. I cut, melted, sawed, vaporized and whatever to get that vulcanized rubber off the control arms. It leaves a knarly cast finish that, in my opinion needs to be machined. So the spindles were machined and UMHW bushings were cut on a lathe to match the diameter of the spindles. I have got 10 years and alot of track hours on this set up and I have been very happy with it. No maintenance.

^ This was the first thing I noticed on the E46 M3 when I switched to Polyflex. The suspension seemed much more compliant over bumps, as if the arms could actually move up and down freely to allow the springs and shocks to do the work. I took the car up my favorite twistie road and then went home and changed the bushes and then back up my twistie road. Like I said before, the difference was night and day.

Any advantages to UMHW over Delrin?

Did you do the same with the upper & rear arms?

https://cimg1.ibsrv.net/gimg/rennlis...0bbcafc59a.jpg
I had just purchased upper arms for $180 each and thought the smaller bushing would provide enough dampening effect. Same issue with the rear control arms, so I left them stock. Made a UMHW bushing for the rear sway bar for some reason. The UMHW is very tough stuff, machines great, long wearing, self lubricating, and real cheap!!

Cool, not familiar with that materiel. Turbo Todd has a big chunk of delrin in the shop he uses for whatever he needs delrin for LOL. I'll ask him if he's worked with UMHW.

I know Jean-Louis made Delrin bushings for his race car, but I thought front upper only. I'll have to ask him. Those loser look like a nice setup.

Agreed.