Trailing arm bushings- Help needed.
 

I just spent a little time looking though the archives and now I’m scared.

My first question is… Is it possible to replace the trailing arm bushings with out removing the axle, brake lines, etc? It looks like I should have plenty of movement so that I can remove the mount bolt and swing it out enough to gain access to the bushings. The only trouble I can see having is if the bushings don’t want to come out. Other than that is seems like a much quicker way to go about it.

Second question… I’m getting ready to install new torsion bars and sway bars. I rebuilt the front bushings a few month ago and I decided this time I would do the rear. I have Neatrix bushings for spring plates and I was going to go w/ poly bushings for the trailing arms since that’s what I got for X-mas. Looking though the archives, it seems the opinions out there are to stay away from the poly bushings. I would love to go w/ Elephant Racing’s monoball cartridges but I need some advice and opinions before I spend $$$.

Help me out here. What have you guys gone with and what has worked and what has not? Has anyone gone w/ the poly trailing arm bushings and wish they hadn’t? Likewise, has anyone gone w/ monoballs and not been happy?

This is a street car w/ interest in get on the track a few times a year.

TIA!

Yes you need to remove the axles to do this job correctly...I don't know how you would knock the old bushings out of the trailing arm any other way. Don't use the plastic bushings for the trailing arm. Use the OEM bushings from the dealer...about $ 80 for all four halves. Neatrix will be a great replacement for the rubber spring plate bushings. You can remove the old material with a utility knife then use a wire wheel to clean it up.

Getting back to the plastic weltmeister type bushing for the trailing arm. It will fit sloppy and you won't be happy with it. The OEM bushing is just fine on or off the track. The monoballs are a step up for those who like the track. I went throught all this last year when I changed mine out. I'm sure others will chime in about the same experience. It really isn't that bad of a job...just time consuming. BTW..you will need a 22mm box end wrench to remove the trailing arm bolts.

I didn't even bother with the smaller ones, just the neatrix bushings. That way I didn't have to remove the trailing arm. :)

yeah, ditto the above.

i am just waiting for t/bars before i do the whole job lot.

i'm going neatrix/oe in the rear.

what a pita that we have remove the trailing arm!

I did mine abount 1.5 years ago. I pulled everything apart to do my bearings. I found that my inboard bushings were severly deformed from 18 yrs of use. I did the same research as you and I fully understand the fundamental purpose of this bushing and it's need to move in more than direction. I opted for the Monoballs. They went in flawlessly and work flawlessly.
They are certainly more expensive and if you drive on the street in all kinds of weather, may not last as long as a rubber bushing. I think the community is pretty confident that this is why Porsche uses rubber. Price and everyday longevity.
How much of a difference do they make? Most people install them not necessarily because they feel different but because it's another variable taken out of the suspension question. Some can quantify their benefits but most are happy just knowing they are there. With the shock and spring plate disconnected, the control arm moves a whole lot easier in my hands than the stock set up (which means it must be doing something). It also makes the assembly and disassembly process a lot easier if you go in and out of there often like I was (adjusting ride height). Alignments are easier too as there's no preloaded rubber fighting the adjustment process.
To do the job right I think you should pull the whole arm and get it on a workbench. You will spend more time up front getting the arms off but 1.)You may find something you didn't otherwise know was wrong in there 2.)You'll save time getting the bushings out and the new ones in. Also take the opportunity to do the rear bearings if you want. Now's the time. You will also get to clean your control arms. Light work with steel wool and they will look brand new. My track inspection mechanic thought I went out and bought new arms.
I used the Neatrix as well. In my case I decided to spend the money on the monoball and not the adjustable arms with Poly bushings. I like my set up and obviously recommend it for all but the pure track car. That should get the poly bushed adjustable spring plate on top of the monoball.

Have fun. You'll be psyched you did it.

I think you should drop the trailing arms. It's not much extra work, but it makes removal and installation of the bushings so much easier. When I removed my arms, and I placed the metal sleeve of the banana arm bushing, into a bench vise. Then, you can rotate and wiggle the arm and the bushing pops right out. If your bushings look like the ones on my '76 912E, then they need replacement. I used a hydraulic press to press in the new rubber bushings. It's a piece of cake when the arms are out.

I used stock Porsche items from Stoddard and Neatrix from Paragon or Pelican. I could definitely tell a difference from the worn original bushings.

I used an angle grinder with a wirebrush to clean my springplate and torsion bar cover. I powder coated them satin black, and they look great. I used Eastwood's Hotcoat system

picture of powder coated parts

They are a little dirty, but it looks nice. In retrospect, I wish I had used something with a duller finish.

Good luck,
Jurgen

Thanks guys. Well, I guess I’ll bite the bullet and go get OEM trailing arm bushings and remove the trailing arms. None of those answers were what I wanted to hear but it’s what I expected.

I didn’t want to have to remove the calipers more than anything else since I just rebuilt and flushed my brakes a couple months ago. I guess it can’t hurt flushing my brakes every other month can it. I’ll some of the cleanest fluid out there, WooHoo!

Dr. Ryan....after you detach the spring plates from the trailing arms....measure the angle of the plates with a protractor as the spring plate rests (you have to remove the bottom bolt in the springplate cover to do this). You can buy a nice one from Granger or Home Depot for $10. This way you can match the angle of the spring plates when you put it all back together after taking the torsion bars out.

I'm upgrading to 22/28 torsion bars and 22/21 sway bars so I will have to reset the angle but I will note the existing angle to give myself a reference point.

I’m still thinking about if I really want to pull the training arms and replace those bushings. I guess I probably should. I’ll loose all my alignment setting and have to get a C/B and alignment anyway but I don’t know.

I kind of felt the same way before I pulled the entire front suspension apart but now it feels like second nature. The only way I’ll learn about the rear suspension is to pull it apart I guess.
:rolleyes:

And just to be sure, the consensus it to NOT use the Poly bushings I already have, right?

I have a document that I created on how to do this. Send me your email address and I wiil send it to you. It's to big to send through pelican. It's not that difficult. I had a blast doing it.

My email Thanks!

Do not use the poly bushings for the Trailing Arm attachment...use the OEM or monoballs.

Yes, do not use the poly bushings. The main reason is that besides the squeaking issue. You can't torque the nut on the bolt that goes through the bushing without collapsing the the pickup point.

The stock bushings use metal washers that have a metal tube that inserts through the center of the bushing that supports the load of the torque. The poly bushings don't make allowance for these washers. The alternative is to drill out the poly bushings to accept the washers but then you probably have a situation where the arm doesn't move as freely as it should.

Save yourself some grief . Buy the overpriced factory bushings.

Bobby

I did this job last year myself and agonized over the same questions as well. Stock bushings (OEM) are what I went with tool. Way over priced and boy did I try everywhere to find a deal.
Bought mine from Pelican. Though the monoball prices are dropping, as new sources are coming out. Check out DARTAUTO (www.dartauto.com) with their new monoball product.

The job is not that hard, just everything has to come off to get those mashed in bushings out. You will have more fun with your Neatrix install. I burned my old swingplate rubber off and there was a foul smell in my neighborhood for quite awhile.
As a level of difficulty, this one is a 6, just time consuming and make sure you get everything tight and torqued when you finish.

HTH.

Maybe Dart used an image of a first-off or prototype and subsequent parts are anodized but these look like they are as machined and not anodized. They may oxidize (although aluminum oxidizes slowly) but it may cause problems getting them out later down the road...like when you want to change the spherical itself. Also make sure they have the teflon lined spherical bearing if you are going to compare apples to apples. I am all for a cheaper alternative as long as they work proportionally well or better. There are all sort of sphericals out there. Some are $5 some are $35 a piece. Otherwise they look pretty good.

Grease those axles!
 

You are going to want to check the grease in those axles anyway, so a quick (ha ha) strip and relube is time very well spent. You will be SO close to getting this out anyway, you might as well bit the bullet and have the peace of mind. Be sure to retorque those mutli-hex bolts at the flange after 100 miles or so.

John

I have this job coming up next weekend and am wondering how much time it takes. I took my engine out yesterday and have new Sway-Away spring plates and OEM trailing arm bushings. So I think that should cut the time down a bit. But can we get this done in one day? I have to install a new 3.2 as well, which I know is no big deal. But suspension work scares me. Thanks.

I can't recall how long it took. I also did mine over the course of a few weeks. If I had to guess I would say that in 6-8 hours (with all of the right tools and a clean shop) I could have done the whole thing including the Neatrix bushings (which take almost an hour a bushing once all of the parts are out of the car). Without the engine and tranny in the way it should be a pretty straight forward job. I have heard that Sway-a-way plates (not because they are sway-a-way but becuase of the poly bushing) are very, very tight and sometimes take a long time to get into the car. Clean and prepare the bushing surface (on the car) very well. Now, getting things reassembled and ride height correct takes awhile but you can't do that until you have the motor in anyway. And it sounds like you are maybe upgrading to a bigger motor (which is heavier) so you need to experiment with proper ride height vs. spring plate angle.

No - I'm just doing a 3.2 - 3.2 swap. Mine is tired and I picked up a recently rebuilt and upgraded 3.2 for a song. Weight should be the same. What do you mean an hour per bushing? I don't need to remove my old bushings from the old spring plates, as I'm installing new spring plates and new bushings. I know getting the old ones off sucks, but I can do that at my leisure before I list them on eBay.

Richard,

If you don't have to R&R the spring plate bushings, that'll save you lots of time. Ripping the rubber off those plates is a little time consuming.

Hopefully you won't run into a sticky torsion bar either. Usually the bar get slightly rusted in the spring plate housing at the outer end. Put the plate assy. in a vise and you can pop the cap off the end of the housing. Beat the bar out with a dowel rod of some type. Put a little penetrating lube on there to coax it out too.

Like the others said, make sure to mark where your plate hangs before you remove it. You can then reinstall it in the same place and not have to hassle with reindexing the torsion bar and whatnot. But, you may be considering lowering your car to the "Euro" height of 25 in. in the back. Still, mark the plate angle on the wheel well so you have a point of reference from which to work.

You'll also want to consider "centering" the new spring plates. They are usually at one extreme (mine were set such that you could only raise the ride height) and won't allow an equal amount of adjustability either up or down.

I can't comment on the inner bushings of the trailing arm. I did not have my motor out when I did my suspension work (only so much room in my garage!!!), so I couldn't remove the trailing arms.

I'd recommend marking the position of the camber and toe eccentric bolts on the trailing arm too. Use some red paint and mark a swab of paint across the bolts and the trailing arm. That'll help you get things aligned at least relatively close to the original settings. You need a 12mm hex key for these bolts by the way.......

I hope you have new spring plate bushing covers too. Mine were pretty bad when I removed them at 65K miles:

http://forums.pelicanparts.com/uploa...ybushcover.jpg

The plates with the new bushings on them are going to be kinda stubborn to install. Spray the bushings with silicone spray and smack the plate in there with rubber mallet.

If you've got a helper, you should be able to do this in a day, each of you doing a side

Guys:
It amazes me that for a car platform that's been around for 30+ years, we're still saying that the rear suspension ride height is a hit or miss proposition with a number of iterations required.
This bugged me so much, that I worked up a math formula to do it right the first time....even with upgraded torsion bar sizes. You need overall vehicle weight and an accurate assumption of weight distribution. The formula was embraced by Thom Fitzpatrick who worked up a simpler software package for this. See his web page for our collaborative effort. It works.
---Wil Ferch

On my SC, I was able to pull the trailing arm bolts w/ no problems w/ the engine installed. Early cars may be different but for anyone thinking about doing this to their later car, no worries.

Also, I removed the training arms w/ the emergency brakes, bearings, and etc. still installed. I didn’t want to replace the bearings at this time and it’s not something that I would need to take everything apart to do, so I didn’t mess w/ them.

I’m having a hard time pulling the torsion bars. I got the left side after fighting it w/ a friends help but the right one is being a b!tch. I’ll try spraying some PB Blaster in there to loosen things up.

Anyone getting ready to do this should make sure to order new CV joint gaskets, I forgot.

Work is still in progress. I decided that since it will probably be a long time before I do this again I would take the time to clean everything up and paint a few things. I’ll post pictures when it’s all back together. I forgot to take before pictures.

I’m upgrading to 22/28 torsion bars and 22/21 Carrera sway bars during this and that’s the reason I’m doing it in the first place. I will need to index the torsion bars and am afraid that it may be hit and miss. Wil, I would love to check out your numbers for indexing. Could you post a link for me?

There is a pretty good amount of information available about the re-indexing. For me I probably set and re-set the assembly 4-5 times. The toughest part is the angle you measure is different when you have just assembled it versus when you set the car down and then lifted it again and pulled the wheel. I think the bushing sticks. So beware of this. The Pelican tech article gives good info on how much the splines allow you you adjust the ride height. I cannot recall what I set my angle at. Make sure your sway bars are not connected when you do the indexing. It's a trial and error thing. Also, another hard part is the window between the spring plate being in the car versus totally off the t-bar (lost indexing) is very narrow. If you can watch that then I would assemble it as a best guess. Lower the car, take a ride height number, do the math to see how lower you want it, then calculate the spline combination to get you that much lower, raise the car, pull the spring plate (not so hard to lose the index) and then reset the t-bars accordingly to your calculations. That should work.

My advice to anyone who is taking apart a 911 rear suspension is to get the later style factory adjustable spring plates. With a little common sence you should be able to get the ride height right with two trys if you are changing tosion bars, one try if you are only changing bushings.

On the monoballs, ours are made of stainless steel. There is no need to anodize. This allows for easier install and removal because of different expansion properties of steel and aluminum and helps prevent aluminum on aluminum galling. We use a readily available teflon lined bearing. The price differential is only a couple of dollars each. If the monoballs themselves wear out they are readily available for about $30 a pair. Part #is COM10T from most supliers.