Necessary to replace trailing arm bushings?
 

I have a very original 84 street-driven carrera that needs a suspension refresh, which I'm about half way through. The complete list (all purchased from ERP) includes:

• F + R sway bar bushings
• Ball joints
• turbo tie rods
• A arm bushings
• camber plate bushings
• F + R shocks (Bilstein HDs)
• F + R torsion bars (hollow 21 + 27)
• Spring plate bushings
• Front wheel bearings

My question is this:
removing the trailing arms looks like a major PITA -- dealing with the brakes, half shafts, etc. I've also been told by my reputable p-car mechanic that the trailing arm bushings are pretty much good for the life of the car, unless you're trying to upgrade for racing purposes (I am not -- just trying to restore stock, or slightly better than stock, performance).

So..............

What say you pelicans who have gone through the rear suspension refresh? Would or did you replace the TA bushings when refreshing your rear? And if so, should I replace the rear wheel bearings while I'm in there?

(by the way...this project started as just replacing my front sway bar bushings. arg!)

Thanks!
Rich

My thought on the matter has been, it's rubber. Rubber bushings don't last 30 years.

I opted to replace them when I did a suspension refresh. The hardest part is getting the trailing arms in and out of the car. Replacing the bushings themselves is a pretty easy process.

I also opted to replace the wheel bearings. Why not when you've already gone that far, right? Honestly though, the tie rods gave me more trouble than the trailing arm bushings did.

It's up to you if you want to go whole hog. Since you're replacing the torsion bars, you're going to need an alignment anyways. Might as well get all the bushings out of the way to avoid another alignment down the road.

If you look at the trailing arm bushings you will see that they can be quite compressed over the last 25 years. The difference can be quite dramatic. On my 930 the bushings were so misshapen that on the top of the bushing was half the size of the bottom. I also found some rust. I think if you are doing the suspension anyway, you should do it. It doesn't take much time. Yes, it can be quite trying reinstalling sometimes but not outside of the realm of what you can do.

Here's my take on your list

• F + R sway bar bushings- easy & cheap, go for it
  
• Ball joints- takes some work but good idea given their age
  
• turbo tie rods- very worthwhile upgrade. I suggest re-greasing the rack while you've got everything torn apart anyway. It's not hard at all.
  
• A arm bushings- big improvement to front end "solidity" New bushings here really restore a solid feel to the fron end.
  
• camber plate bushings- I wouldn't bother with these IMO.
  
• F + R shocks (Bilstein HDs)- definitely. I bet you find your front shocks are toast
  
• F + R torsion bars (hollow 21 + 27)- save your money, as the improvement is marginal at best and your shocks won't be optimally valved for the springs anyway
  
• Spring plate bushings- definitely. You can't go wrong with rubber/Neatrix. I just did a set of these on my '87. I'd previously done them and they withstood a lot of abuse.
  
• Front wheel bearings- if the bearing races still look good, I see no reason to replace the bearings. Simply repack with good grease and you're all set. Front wheel bearings on these cars are VERY durable.

Trailing arms bushings do deteriorate with age. I've seen them show a noticeable amount of cracking in the rubber section. So take a look closely at yours. I'd replace them with OEM style "silent bloc" rubber bushings. The aftermarket monoball cartridges have spherical bearings in them that can wear out significantly with age. Be they std. steel races or teflon-lined, they both can wear out and develop squeaking. For street use the rubber is w/out question the way to go.

Trailing arm removal is not that bad. Axle shaft removal is just a bunch of M8 bolts and it'll also give you the opportunity to inspect your CVs for grease & wear. Brake line disconnect will be your toughest task IMO.

RE rear wheel bearings, I would consider replacing those before the fronts. Rears tend to go bad more often than fronts. That being said, both are very good bearings. Key to bearing life is quality grease. Often times the rears fail simply because of the economical grease used in them.

+1 on doing it as the others described. You spend all that effort to do a full refresh and leaving out a key component won't make sense.

They do not last the life of a car (a driven one anyway)...
http://forums.pelicanparts.com/uploa...1351191940.jpg

Plus...now you get to clean and refinish everything and your handling will be so much better.

I guess I knew the answer to my question before I asked it...just needed the moral support I guess.

I am resisting the urge to drop another $$$$$$ on new axle shafts, calipers, rotors, pads all around, as the car really does stop fine and the pads are at least 50%. But I will do the brake hoses and whatever fuel lines I can get to.

My car thanks you!
Rich

removal done already
removal done already
done already
Just waiting for the A arms to come back from powder-pro in new bedford.
I couldn't resist...cheap enough and I'm replacing the shocks.
Actually I think the shocks are ok, but since everything else will be new...
My front torsion bars had some material worn away from the worn out A arm bushings. New stock ones from porsche are ridiculously expensive and I didn't feel great about putting another set of 30 year old ones on, whether that's rational or not...
Chuck doesn't sell stock equivalent replacements, so I got the most mild upgrade I could, and since I upsized the front I had to do the same to the rear to keep handling balanced. After this I'll need an alignment and CB anyway.
I have chuck's replacements on the way, along with his removal tool.

What's the grease you guys recommend? I have the swepco lubri-moly CV joint grease left over from rebuilding the CV joints on my 914...is this a good choice to pack these bearings?
I have a mapp torch and flare nut wrenches...can't be harder than my 914 was, right?!
you can bet if I've got these out of the car, they're getting new bearings.

If the axles are in good shape in terms of CV hub surfaces not pitted, you can just clean out the old grease and repack with your Swepco. It's good for bearings and CVs. Swepco 101 is a really good EP grease with good sticking power.

If you can rebuild the suspension, you can rebuild the calipers. Pretty easy with some compressed air and a block of wood to block the opposing piston. And your brake lines should be no different than the 914. Just use some penetrant (i've heard tobasco sauce is incredibly effective too...) and patience.

The most important fuel lines to look at are in the engine bay under & behind the intake manifold. There are three lines you need to inspect:

1. Small line at the driver side fwd (rear) of engine. It's a tight bend radius short hose that splits over time. Very dangerous.

2. Y-shaped line that runs from the fuel filter in rubber, goes to the center, rear of the engine, becomes solid steel, goes under the manifold toward the fan, hits a tee at the fan and connects to the fuel rails with two more sections of rubber. This line is a notorious leaker if it is original single crimp swivel fittings. The later updated fuel line is non-swivel with double crimps. A lot of people choose to have hose repair shops rebuild this line with new hose & fittings. Amazon Hose in Tampa, FL and Len @ Autosport Eng (BoxsterGT here on the forums) do a nice job of rebuilding this hose.

3. Same thing as number 2 above applies for the rubber hose that connects the fuel rails at the front of the engine, between the fuel pressure damper and fuel pressure regulator.

If your pads and rotors are in fine shape, no reason to replace them. Replace later when they're worn out. For street use, decent rotors and ample pads are more than sufficient. Stock Carrera brakes are very good brakes.

Good call on the T-bars if that's the smallest Chuck makes. Stock torsion bar sizes are plenty suitable for street use, so I don't see that the incremental size increase makes a huge difference. Once you get into much larger torsion bars for only street use, the ride harshness tends to outweight the handling benefit IMO.

I will be replacing the rear rubber bushings in the coming year on my '74.

My thoughts on bushings: Every car I have ever owned, I have replaced the rubber suspension parts and the ride quality has always improved - no matter the prior condition.

I just finished the front bushings on my car and I was surprized how bad the old bushings were. See photo below. I would think that with the fronts being this bad and the front is lighter, the rear will be just as bad - even though they look ok from the outside.

http://forums.pelicanparts.com/uploa...1351196800.jpg

This is good thread for me to follow...I have an '84 that I recently acquired in the spring, and at some point I'm sure I'll need to go through the suspension. Can you give me a ball park of the $$ you have into the parts listed above?

I'm fairly handy so I'm quite confident I can do this myself...any specialty tools required?

I replaced my '84s trailing arm bushings last year at ~300,000 miles. They still had some life left. The A-arm and spring plate bushings, however, were shot.

Try this just for kicks and play with the options:
ELEPHANT RACING Suspension Packages for Porsche 911/912/930

Suspension1

I bought my components over time from both vendors, some directly and others through PP.

As Zippy said -- go to the elephant racing website for prices. Big ticket items for me were the shocks and torsion bars -- these items about equal the cost of the full set of replacement bushings. By far, the most cost effective way to refresh is to go stock or close to it.

Required...well...I think so, depends how macgyver-y you are.

For the front:
you will need the pin wrench socket to install and torque the ball joint nut, plus a torque wrench that can measure 233 ft lbs. I also used this socket to remove the ball joint nut. I also highly recommend a tie rod separator. Both tools are sold by our host and come up for sale occasionally in the classifieds.

If you buy the Elephant Racing A arm kit, Chuck includes some special tools to properly install them. A press makes it easy but a large pipe or bar clamp also works (I'll be going that route).

For the rear:
The spring plate bushings are bonded to the spring plates. You need to cut or burn them off. Chuck sells a spring plate bushing cutter, which I purchased for that job.

To replace the rear wheel bearings, there's a special porsche tool but others have assembled similar bearing pullers using hardware store parts. I'm going to take the trailing arms to my p-car wrench and have him install the bearings and bushings.

That's pretty much it I think except for a MAPP torch and a BFH. There are many threads on this site documenting suspension refreshes to guide you.

I haven't added it all up. So, I don't know the exact price to the penny. However, I think the suspension parts (not including the brakes) came to around $2,000

The only special tools you need are to replace the rear wheel bearings, and a special socket for the ball joints. The A arm bushings from ERP come with their own tool. Don't bother buying the tool for the spring plate bushings, it was useless. I ended up using a torch and a razor to take them off.

I am doing the front suspension currently. Went with rubber bushings from elephant, new torsion bars, bilstein shocks, sway bar bushings, ball joints, tie rods. The bill was just north of 1k.

Add to that list rear sway bar drop links. Getting the old ones out was not easy, I had to use an impact wrench and alot of penetrating oil on the lower nut/bolts on them to get them to break loose. The upper bolts (into the rear trailing arm) came out easily w/ a breaker bar and not too much effort.

Below is a photo of my rear drop links. The improvement in handling with new links was significant, much less "initial turn in" lean from the rear end. Granted one of them was damaged from impact, but even the 3 non-damaged connections were very loose and rubber was totally disintegrated.


http://forums.pelicanparts.com/uploa...1351210103.jpg

Nick, what drop links did you use as replacement? Mine are gone too and I am redoing the entire suspensions with bits from ER and Rebel Racing.

Mine were old and shot too , now very happy with the Tarett adjustables (can take out preload).

Thanks Tazz, I looked them up and like the features and the price is not too bad compared to OEM either!:)

I installed the Lemfoerder OEM ones from our host. $50 each including new bolts.

If you are going to upgrade to more robust ones, you may want to consider installing the reinforcement kit for the rear sway bar to body attachment points, which have been known to bend on the 911SC at least, not sure if they were made more robust by the factory on the later models (Carrera-on).

I replaced the rear trailing arm bushings last year. My experience in my '86 is the trailing arm bushings were in very good condition - very little distortion or aging of the rubber, so did not notice an improvement. However, they are new and I will never touch then again.

Mapp gas will remove the inner sleeve and the rubber in about 10 seconds, then you have to remove the outer sleeve. I got a hacksaw and carefully made a cut in the outer sleeve, ensuring I did NOT cut into the aluminum arm. Once the outer sleeve could be bent inwards, heat and a hammer removed them. It took me close to an hour to remove each bushing IIRC. I'm not sure I could have avoided the hacksaw with lots of heat.

You need to make certain both bushings are fully seated or they won't fit back in the mounting point.

Thanks Nick. I am looking at the Tarett adjustable as they are around $260 for all 4 and are adjustable which will help with corner balancing.
I am not planning on increasing the size of the sway bars so I am not too concerned about reinforcing the shock towers, although I will be checking the "health of the metal and presence of rust.

Bumping this fairly ancient thread as I'm about to do much of this work and this seems one of the better threads I've found discussing it...

'85 930 Turbo I recently acquired, stock suspension, drives decently but I know it's way off what it can and will be.

First I'll do a thorough inspection, then I guess I'll have to decide what bushings or monoballs to use. Strictly 'fun' mountain and canyon drives. Little or no track work, I have other cars for that.

Any thoughts or advice welcome, as well as any pointers to other threads that might have great info.

For a street car, I like the OE rubber bushings. On the recommendation of several people, I put the Rebel Racing solid bushings in my 1973 street car. I can't detect much difference in road noise on smooth roads, but on crappy roads they do transmit more NVH (noise, vibration, harshness). On the advice of William Knight (Knightrace), I have stayed with the rubber bushings in the rear arms, because the monoballs will increase NVH more.

If you usually go out for short drives, or your roads are mostly smooth, maybe solid or semi-sold bushings will work for you, but I drive distances with my car, so I want to minimize NVH.