rear suspension refresh -- any last minute tips?

[rwilner]

My front suspension refresh is done and tomorrow I'm getting started on the rear. The plan is to R&R the following:
- spring plate bushings
- trailing arm bushings
- rear sway bar bushings and drop links
- rear wheel bearings
- rear torsion bars
- rear shock absorbers (new bilstein HDs)
- trans mounts (I did the engine mounts already)

I am armed with my bentley, 101 projects, having done similar work on my 914, and have read the numerous threads on this:
Newbie attacking rear bearings, need help please
Banana Arm Bushings Don't Fully Seat - OEM/ERP
Elephant Racing Rubber Bushings - Brief Report
Time to replace 30 year old suspension - little help please?
Rear Wheel Bearing Removal

I am *not* doing any work to the brakes or axles/CVs at this time unless there is an obvious issue when i'm disassembling, because they are fine from a performance perspective.

I have an appointment for a full alignment / CB in 2 weeks so I need to be done by then...I really want to give her one or 2 more spirited runs before changing the
oil, wash, wax, vacuum, cover and putting her to sleep for the winter.

Any last minute tips or tricks from those that have BTDT before I dig in?
thx!
Rich

[DRACO A5OG]

3.2, ok, are you upping the torsion bars, if so up the sway bars to our brother 87-89 diameters. This will help the sway bar mounts from being weakened due to higher stresses from the upped t-bars. If not, then you are good with OEM sways.

Go with Bilstien HD fronts and Sport rears, aggressive street or light track, very enjoyable ride as recommended by Steve Alarcon for us annual or bi annual trackers

[zippy_gg]

Sounds like a fun project, one that I am going through now.
Did you drop the engine?
I dropped mine to get better access to the trailing arms and also to address minor rust repairs.
You may discover that you need to replace the shoes on the emergency brakes once you remove the rotors.
Your torsion bars may be fine, mine were and still covered with grease, so unless you are replacing with stiffer ones you may save yourself some money...
I found that removing the hubs and then bearings were the biggest PITA.
The nuts on the spring plates were very difficult to remove; heat is your friend. I mushroomed a deep socket before using heat.

[myamoto1]

Make sure you use Porsche trailing arm bushings. I originally bought the OMP version and the fit was horrible. I had to destroy them to remove them (only half installed) and replace with Porsche bushings.

Check for cracks around the swing arm plate studs. Many will say any gap is only a crease from where the weld meets the sheet metal - that was not the case with mine. I'll see if I can find my thread with pics on what to look for.

Thread found: Cracked spring plate mounts???

[E Sully]

Make sure to put the brake backing plate on before you press the hub back in. The bearing gets ruined every time the hub is removed. Seems a shame not to grease the CV's while your in there. Filthy job, but worth it.
Here's more recent threads on rear suspension.
First suspension job
http://forums.pelicanparts.com/paint-bodywork-discussion-forum/708311-torsion-bar-tube-corrosion-repair.html

[will hung]

I would recommend getting a set of the bearing retainer plates from Smart Racing Products. The age of these cars are at a point that the bearing bore in aluminum trailing arms are getting egg shaped, and these beefier retaining plates do a much better job of supporting the bearings than the flimsy OEM pieces, extending the life of the replacement bearings.

[michael lang]

Since everything is going to be disassembled, my suggestion would be to put it back together with adjustable spring plates. That suggestion was made to me & I'm so glad I listened. That upgrade is worth every penny I spent and your alignment tech will be do grateful.

[AlfonsoR]

First of all, great thread, great participation and info..

I need to do suspension refreshening on the front and rear so I hope Rich doesn't mind me inserting my questions...

Originally Posted by DRACO A5OG

Go with Bilstien HD fronts and Sport rears, aggressive street or light track, very enjoyable ride as recommended by Steve Alarcon for us annual or bi annual trackers

I thought the HD and Sport had the same valving? I guess I must be wrong. What are the benefits of going Sports rears and HD fronts?

Originally Posted by michael lang

Since everything is going to be disassembled, my suggestion would be to put it back together with adjustable spring plates. That suggestion was made to me & I'm so glad I listened. That upgrade is worth every penny I spent and your alignment tech will be do grateful.

Where is a good place to get the adjustable spring plates? Do you have any part numbers for them?

[DRACO A5OG]

Sports all around will give you a very harsh ride. For a full tme track car that is fine but for street, it very rough per Steve Alarcon of Johnson's Alignment

[kinein]

Originally Posted by DRACO A5OG

Sports all around will give you a very harsh ride. For a full tme track car that is fine but for street, it very rough per Steve Alarcon of Johnson's Alignment

I am glad that you are also doing this thread. I got the same recommendation by steve last weekend at johnsons alignment. With suggestions for tbar upgrade. Looking forward to following this restoration of the rear suspension. I already bought my hd front shocks and sport rears. Now i have to get all bushings and i am goin to replace wheel bearings also while im there.

[Packet82]

Do yourself a favor and check the condition of the brake lines while you're in there. You have to take them off to get the trailing arm out anyways.

[RWebb]

replace brake hoses with new rubber unless you are certain they are less than 8 years old

[Chuck Moreland]

Originally Posted by rwilner

My front suspension refresh is done and tomorrow I'm getting started on the rear. ...


Any last minute tips or tricks from those that have BTDT before I dig in?
thx!
Rich

Take your time and don't force anything off/on.

Specifically the hardware securing the spring plate to the trailing arm can be difficult to remove and replace. Very often the threads get knackered in the R&R process if not done right. Use an appropriately positioned jack to rotate the trailing arm to relieve the tension on those bolts. And don't be surprised if the threads are already knackered by a previous effort. You may find you want to replace this hardware.

You need to get the angle right on the spring plates. It will be different due to your new torsion bar diameter. See this to determine the angle:
911 Spring Plate Angle Calculator

Hopefully you have adjustable spring plates to fine tune the height. If you don't, get them.

[michael lang]

Where is a good place to get the adjustable spring plates? Do you have any part numbers for them?[/QUOTE]

I bought mine from Jim Buckley at Buckley Racing. I've purchased a couple of things from him. The rest of my suspension stuff is predominantly ER. Good luck in your rebuild.

[rwilner]

Tear Down Success!


Well, sort of...

I removed the spring plate retainer and am having a heckuva time getting the spring plate off. Any tricks or do I just wiggle and whack it till it comes free?

[zippy_gg]

Originally Posted by rwilner

Tear Down Success!


Well, sort of...

I removed the spring plate retainer and am having a heckuva time getting the spring plate off. Any tricks or do I just wiggle and whack it till it comes free?

I used a long and thick screwdriver as a pry bar between the body of the car and the spring plate, working my way around, and it came off without too much of a fight. Then again I found that the torsion bar was still well greased up, which probably helped with the removal of both the plate and the TB.

[will hung]

make sure you press against the studs for the spring plate cover mount. Otherwise you'll bend the sheetmetal around the torsion bar hole.

[rwilner]

Originally Posted by Chuck Moreland

Take your time and don't force anything off/on.

Specifically the hardware securing the spring plate to the trailing arm can be difficult to remove and replace. Very often the threads get knackered in the R&R process if not done right. Use an appropriately positioned jack to rotate the trailing arm to relieve the tension on those bolts. And don't be surprised if the threads are already knackered by a previous effort. You may find you want to replace this hardware.

You need to get the angle right on the spring plates. It will be different due to your new torsion bar diameter. See this to determine the angle:
911 Spring Plate Angle Calculator

Hopefully you have adjustable spring plates to fine tune the height. If you don't, get them.

Chuck
For some reason I'm just reading your post...not sure how I missed it...
I have the stock spring plates for my 84. I believe these are adjustable via the eccentric bolts. Is this what you're referring to, or are you recommending I get something else?

I would prefer not to install trick adjustable spring plates at this time -- this is a 99% street car that's very original and I really want to retain a stock look.

thx
Rich

[PorscheGAL]

Here is a lesson that I learned on doing the suspension work on my 911 and 930 this year. I learned that the torque changes on the toe and camber bolt. When the bolts are new, you can torque them to 85Nm. When old, you torque them to 60nm.

This is in the 930 shop manual. I found out the hard way by stripping the camber bolt twice until I discovered this in the manual. I guess I was lucky on the 911 because I didn't strip any of those. The bolts are the same in both cars. The camber bolt is not cheap to replace and I did it twice!

Also, the manual says to add a lock washer to the toe nut and bolt. I believe it comes on there, but the manual says to add one to an "old" bolt.

This information is found on page 42-12 Rear Wheel suspension (v.84) of the Turbo Carrera Workshop Manual.

[DRACO A5OG]

BFS is your best friend =)