Elephant Chuck

A little background:

I recently met Rennlist regular “Bill” at a local swap meet. He was looking to set up the suspension on his 944 turbo with some performance bushing replacements and asked if I had anything for the 944 (I manufacture a line of performance suspension components for the 911, the company is Elephant Racing).

My answer was no, but I’d been thinking about creating some 944 parts and with Bill offering up his 86 turbo as a test-mule for development purposes…….. This looked like the right time to develop some 944 pieces.

So the plan was put into motion; Bill dropped off his car and I went to work. I soon had the 944 up on jack stands with the suspension parts off. I gathered the information I needed to design the parts, in process now.

As luck would have it, the spring plate bushings are similar to the 911. With some lathe work I was able to adapt a set of 911 Polybronze Spring Plate bearings to fit. I set about to install this prototype set in Bill’s turbo.

I couldn’t find a good step-by-step for 944 spring plate bushing installation, so I thought I’d create one. I know the 911 suspension intimately and have learned a few tricks that ease installation of spring plate bushings. The 944 rear suspension is very similar save for a few notable differences. Most of my tricks apply.

I took lots of pictures, so I am breaking this how-to into three separate posts. Eventually I’ll get this cleaned up and posted to my web site.

Part 1 will be spring plate removal, part 2 bushing replacement, part 3 spring plate installation. Without further fanfare or introduction, here is part 1:

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Click any picture for a larger view.

Put the car up on jackstands, or a lift. At a minimum you need both rear wheels up in the air, but the job is easiest with all 4 wheels up. Remove both rear wheels.

Remove 2 bolts attaching spring plates to the trailing arm.*Remove the sway bar drop links.




Popular wisdom says disconnect the brake line flex hoses, remove the exhaust, and drop the torsion bar tube. I found this wasn’t required. It is possible to tilt the torsion tube down, one side at a time, and gain the required clearance.

Do remove the spring clips that hold the brake line flex hoses to the trailing arms and the tub. Pulling these clips off affords a couple extra inches of slack on the brake lines.




Pull the trailing arm clear of the spring plate. You will need to remove the bolt that secures the trailing arm to the torsion bar tube. On the driver side you will need to remove one side of the axle to avoid interference with the muffler. Your goal is to have the spring plates hang free without interference from the trailing arms. Lifting the trailing arm with a jack will help.




You want the spring plate to hang free so you can create a reference line marking its angle relative to the torsion bar tube. This mark will be extremely valuable when you re-assemble to avoid repeated attempts at re-indexing the torsion bars.

Draw a pencil line as shown:




Again, be sure the trailing arm is not interfering with the angle of the spring plate. If you plan to re-install the same torsion bars, your goal will be to re-install the spring plates with the same angle. If you are installing stiffer torsion bars, you will need to install the spring plates a bit higher than the reference angle. The amount will depend on the stiffness of the torsion bars, but at least you have a staring point to reference.

Remove the rear bolt that secures the torsion bar tube to the chassis.

Remove 4 bolts surrounding spring plate, 1 bolt from forward bushing, and 1 bolt from the rear mount.




You will need to pry the forward bushing down to free it from the bracket.

You should now be able to tip down the torsion bar tube, one side at a time. Be sure you are not putting excessive stress on the brake flex hoses.

Remove the spring plate cover. Remove the rear section of the rubber rocker valence.

Pull the spring plate from the torsion tube and remove. The torsion bar sometimes sticks in the spring plate. Usually it can be freed by rocking it back and forth while pulling.

With the rocker valence removed and the torsion bar tube tilted down you should be able to fully remove the spring plate and the torsion bar.




That's it for part 1. Part 2 will cover bushing removal and installation of the the bushing replacements. Link to part 2

dave120

Excellent...I'm going to make good use of this info when I install my Delrin bushing when I change my t-bars soon! Great writeup...I'll definately be looking for the rest

Sami951

Hold on - you're saying it's possible to remove / replace the torsion bars without dropping the entire rear axle..? Or did I just miss that part..?

Elephant Chuck

Yes it is. Just tilt the torsion bar tube down, one side at a time. You also need to remove the plastic rocker cover at the rear to get a little extra clearance.

Look in this picture:



Both the spring plate and the torsion bar can be pulled right out.

Alpine951

How much room is needed on the side of the car in order to slide the Tbar out? I only have a one car garage.

Elephant Chuck

You can probably get away with as little as 2 feet, but that will be cozy. If you can squeeze in to do the work, you'll be able to get the tbar out.

ehall

I'm bumping this for a small addition. As i was installing my bilsteins, I came to a few very important realizations.
1. The upper shock mounts, lower shock mount on the right side, and a few other bolts, are virtually impossible to remove by hand, on jack stands. You need and impact wrench, because of the orientation of the right side shock mounts.
I reccomend taking the car to a shop with a lift, and having them break loose the following bolts.
Both lower shock mounts.
Both upper shock mounts.
The two bolts (one on each side) that you see with the red circle in the pic immediately above.

Also an important note. This write up begins by telling you that Chuck has already removed the suspension parts. That means the shocks have to come off first.
I ended up taking the car to a guy, and had him loosen up what I spent four hours trying to muscle off. No amount of PB BLaster will help you remove the lower shock mounts. I'll add more if it comes up.

blodstrupmoen

no problem loosening all shock mounts by hand, but make sure you have good jack stands and a couple of support jack stands at the back..
If they are too tightened, you could use some heat on them.


But ehall, how is the right side shock mount oriented different than the left?

ehall

You have to loosen it to the left. It can't be done from beside the car, and You have get the car up high enough to put enough torque on the nut. If it was installed with an impact wrench, you can't get enough torque to remove it, without an impact wrench.
I wouldn't use heat on that bolt either, unless you plan to replace it. It carries a very high load, as it is the only lower shock mount.

blodstrupmoen

Okay, I always lift the car high enough to get under and work properly , and I use a long breaker bar ..
But you better be sure the car Is steady on the jack stands before using to much force..

Just sold my almost new koni shocks , think I only used 10min to loosen both shocks..
but then the car is already on jack stands.

Always loosen the lower ones first, that makes it a lot easier to loosen the one at top.

theedge

I didnt have any big issues with getting any of those bolts off....

500

Did you have a jack or something under the trailing arm to keep it from extending fully? I believe if you jack the car up and just let the trailing arm hang, then the torsion bar will fully extend the shocks and put a lot of tension on the bolts, which will make them harder to loosen.

If the set-up is stock (i.e. just the shocks, no coil-overs) then there is almost zero load on the shock bolts, the shocks do not carry the weight of the car. Think of it this way: If the shocks carried any weight, they would just compress until they are bottomed out.

nine-44

Nice write up, I will add a little detail that would help. The T-bars actually have preload to them. There is a bolt that will stop them from unloading. With that bolt in place, they will stop before unloading to give an accurate reference point. Just trying to help tho.

I found out by accident that there was still load on them. I pulled the shocks, they dropped down, but only to that bolt. I forget how exactly that I was pulling it apart but it about took my head off when it did unload. I edited the pic to show what I mean. That bolt acts kinda like a stop...

Techno Duck

Heres a trick to get the lower shock bolts loose. Using a box end of a wrench or ratchet, use your floor jack to jack up the end of the wrench or ratchet. Worked for me both times, im a scrawny guy, so it was necesary. Just make sure you dont have your face anywhere close in the event it slips or breaks the ratchet / wrench.

blodstrupmoen

Yes , I use a floor jack under the trailing arm to keep it from extending fully. Works very well for me, both with or without coilovers..
I have changed rear shocks on several 944`s never had any real problems.
Also A tap on the bolts head could "waken it up" and make it easier to loosen the bolt.