Trailing Arm bushing replacement

[Gunter]

Agree with Walt:
If there is no evidence that these bushings need replacing, leave them alone, especially if you don't want another alignment.
They have very little wear over the years unlike the main bushings for the T-bar.
With 160k miles, I replaced the T-bar bushings with Neatrix and found no movement in the smaller rubber bushings.
They seem to be a PITA to replace with the arm in situ with no noticeable result.

[munsonbw]

Walt,

Thanks for the update. Looks like I may get away with saving $200! I will evaluate them when doing the other work.

[burgermeister]

Thanks Walt, Chuck et al !

I was just wondering about replacing these. My Bentley doesn't even mention them, and here, first post I get to, removal, installation, need, and methods are all documented. Plus it convinced me to leave 'em be, saving $200 and what appears to be several days of work (for a retarded monkey like myself).

Just for kicks I used Regular Expressions in the search field, and it appears to have worked (though it's inconclusive whether it's glob or regexp pattern matching). Am I dreaming?? I guess it makes sense, and boy am I a dumba$$ for having searched with plain jane words all this time.

[rnln]

looking at these parts and understanding how it works, I don't see why you have to replace the metal pieces. If there is anything degrade, it must be the rubber pieces. So why do you have to challenge it? Can someone tell me the reason why we should replace the metal pieces when replace the rubber bushing?

[sjf911]

They are pressed together from the factory as a sandwich of outershell-rubber-innershell and would likely be very difficult to separate. I don't recall having too much issue replacing mine. My old ones came out in one piece. The new ones do require some care in pressing back into the trailing arm. This would be a very difficult job to attempt in the car even with the engine and tranny out. It is reasonably easy with the trailing arm out and using a hydraulic press.
I actually did this job twice, once when I replaced the OEM with mono-balls and the second time to go back to OEM rubber. Mono-balls turned out to be too noisy for my mostly urban driving. Also, my impression of the original trailing arm bushings was that they were still in pretty good shape when they came out unlike the major load bearing bushings on the torsion bars.

[Walt Fricke]

I have removed the rubber bushings with the banana arm still in the car. I think the transmission was too, but memory is fading.

To remove I had to destroy the metal outer part. I used a small chisel to pry the steel lip up some, and then to poke a hole through it. This gave me enough leverage to pry one out. Then it was easy to punch the other one out from the backside, so to speak.

I was installing spherical bearings, which are a cinch to install once the old stuff is removed. I think it would be very difficult to install new stock rubber bushings with the arms in the car. You can't really pound on the loose end of an arm effectively. But clever use of big C clamps might do the trick.

Good thing was the alignment didn't really change. The spherical bushings are centered, whish is at least where the rubber ones should have been.

As with others, I rate this as a low value/low priority job for a street 911.

Walt

[RWebb]

I can't remember how I replaced mine but I know it wasn't a big deal (or I WOULD remember it).


I wonder if there is any way to check them if contemplating replacement...

[burgermeister]

Based on a fair amount of visible dry-rot and my tech inspection shop's recommendation to do them when the engine & trans were out for some reason, I replaced mine yesterday. As it turns out, the dry rot was confined to the rubber lip of the bushing. Bushings would have been fine for another decade or two ...


My hats off to anyone who managed this with the arm inside the car. I could not even move the arm enough to get a clear shot at the bushing. Happily, removing the arm isn't that time intensive, and the brake fluid will be replaced in the spring anyway. I then tried (and failed) with various punches and chisels to remove the bushings (and later the outer can). In the end, I needed heat on the inner, which then popped out with a screwdriver. Then the rubber chunk was a piece of cake. The outer can refused to give up until I broke down and used the hacksaw method, at which point it took maybe 15 minutes to remove the outer can & press in new bushings...

I was fretting how to tighten the bushing bolt with the arm in the 'normal ride height' position, but with the banana arm separated, I can just move it to where it belongs & torque the bolt, and then reconnect the spring plate. Or so I think.

I very carefully marked the arm & springplate for alignment. I'll see how it worked when it (hopefully) all goes back together in the spring.

[hessel1974]

I had this planned as a winter project, but reading all the stories here and the fact that my bushing don't look that bad, best would be to leave them alone.

But for argument sake, whatis the chance of taking the banana arm bolts out WITHOUT removing the engine and tranny? I would consider taking the tranny mounting bolts out to lower the tranny/engine assembly (2.2 with 901 tranny) a bit to be able to either take the banana arm bolt out OR grind through them and replace these with new ones.

Is this at all doable or am I going to frustrate myself beyond belief?

Thanks!

Hessel

[Bill Verburg]

Where are you guys getting the rubber bushes from? I don't see them on ER's site.

I'm looking to do my '76 this winter.

[burgermeister]

My bolts were on the outboard side, nuts on the tranny side. Took at least 250 - 300 ft*lb to crack them loose. Not sure there would have been sufficient access for the socket & breaker bar with the tranny anywhere close by, nor enough strength in my puny arms to loosen it while lying under the car. Though I think the normal way is for the bolt to be on the inside?

I got the rubber bushings from Pelican. Various other outfits (part$geek) have "URO" non-Porsche replacements for $30 ea. Considering the effort involved, I went with the Porsche part.

Pelican Parts - Product Information: 901-331-059-00-M100

[Bill Verburg]

Originally Posted by burgermeister

My bolts were on the outboard side, nuts on the tranny side. Took at least 250 - 300 ft*lb to crack them loose. Not sure there would have been sufficient access for the socket & breaker bar with the tranny anywhere close by, nor enough strength in my puny arms to loosen it while lying under the car. Though I think the normal way is for the bolt to be on the inside?

I got the rubber bushings from Pelican. Various other outfits (part$geek) have "URO" non-Porsche replacements for $30 ea. Considering the effort involved, I went with the Porsche part.

Pelican Parts - Product Information: 901-331-059-00-M100

Thanks! I didn't think the oems were available

[hessel1974]

I always heared that the bolt is on the outward side as standard, but that a lot of folks turn them around when the motor is pulled. I wasn't aware of this when i did my engine, so the bolt is on the inside/tranny side.

I'll have a good look when the car is on stands. Thanks!

[AlfonsoR]

suspension rebuild, hmmmm

[RWebb]

this might be a good time to discuss experiences with the rubber ones vs. the Elephant Racing monoballs...

[Chuck Moreland]

Interesting to see this old thread pop back up.

I replaced a set of trailing arm bushings today, with the arms in the car. Having done this a bunch of times, it is pretty straight forward. It took just over 1 hour. As always experience counts. The first time you do it, it takes a lot longer.

Having the car on a lift makes a massive difference and makes this very doable. Without a lift, it is a struggle.

And having a helper makes a big difference. The helper assists to stablize the arm while driving out the old bushings, and pressing in the new. Also helpful to wrestle the arms in and out.

It can be done solo using clamps to hold the arms, but a helper is best.


To those looking for the Elephant Racing trailing arm bushings options, we have OEM hardness rubber, sport hardness rubber, and monoballs. pictures and descriptions are available on our website and all can be ordered through our host.

[Sebscst]

While trying to remove the bushings i cut a "little" too deep trying to removing the metal liner (pita) with a hacksaw. Btw after beating on them for 30 with no movement did this and they came out with 2 whacks, just wish i had'nt gone so deep. Ill be replacing them with ER mono balls if it matters.

[Sebscst]

I have no idea how this happened meant to start a new thread.

[chrismorse]

I'm going through the front mechanicals now and it has been a couple of years in the process. I'm glad I didn't shread the back end too.

I'll wait 'til I have driven the car for a few months to pull the trans for a redo, then, pull the rear suspension for the rebuild.

My choices, for a fun '74 27 CIS,street / occasional DE set up:
Front: Sandblasted struts & arms Por 15
.Bilstein HDs, ER a arm bushings, ER sport hardness strut top bushings, PMB calipers, new mc, ss lines, ducted air to the front discs,new bearings & Zimmerman zinc stock discs, O'hauled rack & pedal cluster. Carrera front bar, new bushings. 21 mm t bars.

Rear: ER rubber spring plate bushings, ER sport hardness trailing arm bushings, '85 height adjustable spring plates, bigger rear t bars, (???), bilstein HDs, 85 Carrera rear bar, ER adjustable drop links. Think I will pull the rear arms out to do the overhaul + bearings and e brake refresh, PMB, zimmermans, ss lines.......

This forum has been a constant enjoyment and has saved me a ton of grief, now if I only were smart too :-)

Just wish I had more time to work on it. A lift would be nice too.

Good luck

,
chris

[Packin4]

Some additional things learned:
1. Heat did not help release the aluminum arm from the death grip of outer casing of the bushing.
2. As others have said, be very careful if cutting the outer casing. NOTE: it's only 1.5mm thick before you are into the trailing arm.
3. If punching out the casing be careful not to punch where the hole is (the trailing arm is hollow, there is about 1/2" hole to the rear). It's possible to bend/chisel the casing into the hole making it even more difficult to extract from the trailing arm.
4. In retrospect, buying Elephant's bushing removal tool would have made this job sooo much easier.