CaptainGSR

I recently discovered that my rear toe links are completely shot (ball joints have significant play in them.)
After more investigating, I came to the sad realization that pretty much anything rubber associated with the rear suspension needs to be replaced.
Having replaced my front bushings with ER sport rubbers last year, I am very tempted to dust off the press and get cracking on the rear end...
There lies a problem: what to do about the ball joints that are still fine? (A-arms for example!)
While the toe links take a beating, are the other ones prone to failure as well?
I would hate to take everything apart, replace all bushings, just to have dead ball joints a couple years from now... and then having to scrap the arms altogether...
In that case I would rather replace the whole arms now... but the prices are nuts!
Any words of wisdom from our suspension gurus?
On abused track cars, are ball joint failures common? This could give me a good indication of how long they can last on a street car like mine.

Bill Verburg

I'd replace the rear A-arms w/ new RS pieces, the leading arm inner joint is a sealed mono-ball that is prone to wear. To go w/ that new RS KT arm, the others are the same on normal and Rs so just replace the inner rubber bushes if necessary and if the outer ***** are still nominal.

On lowered track cars the ball joints have been known to fail, PMS feels that the failures are attributable to improper assembly and issued a procedure to be followed, basicly inspect the parts before assembly for any sign of wear on bothe the ball and wheel carrier socket, no lube to be used, torque to 81NM while holding the stud w/ Torx T40

Martin S.

"On abused track cars,", please...there are properly exercised cars. They need their exercise. Prior to installing the complete ERP rear set up, I never had a program with ball joint failure. I have had the ERP on for nearly 2 years, no failures and the car's handling is exemplary.

k722070

seems like those ball joints are pretty tough. but you should just accept that ball joints, along with wheel bearings and bushings are a wear item on a track car.
the good news is once you take apart the rear suspension the 2nd time is easy, 3rd is even easier.
you could price out the difference for trw vs rennline control arms and just decide its more bang for the buck to use rennline. at least then you can swap out the ball joint every few years.
nothing you can do about that a-arm but stockpile replacements.

Martin S.

I was long ago sold on ERP...the Rennline products seem too familiar, almost. I think was out first with the products...whatever floats your boat!

Mike J

Wearing out of various rear suspension components seems to be a more common experience these days - I keep having cars in with worn toe control arms, front steering control arms, etc. Another thing that seems to be happening is more occurrences of excessive play in the rear suspension subframe mounts - they also can get loose.

As a point of reference, I replaced pretty well all the arms this june on one of the local 993TT's here, and here are some prices (in June) from Sunset:

#3 – 993 331 043 00 (2 pcs) - $244.87
#4 - 993 331 045 03 (2 pcs) - $212.38
#5 – 993 331 047 03 (2 pcs) - $212.38
#6 – 993 331 041 02 (Left) - $517.05
#6 – 993 331 042 02 (Right) - $517.05

We opted to go RS for the #6 part.

Not cheap, but then we knew both the ball joints and the inside joint were new.

Cheers,

Mike

Bill Verburg

#6 RS (2009 prices)
993.331.041.81 A arm /L RS RS $508.10
993.331.042.81 A arm /R RS RS $508.10

you ought to use
#4 993.331.045.80 Kinematic Control Arm x2 RS, top rear $196.67ea


#6 RSR(2013 prices)
993.331.041.80 A arm /L RSR w/ mono-ball $543.60
993.331.042.80 A arm /L RSR w/ mono-ball $543.60
#3-5 ought to be monoball type w/ these Rennline is a good source

Mike J

When I checked with Sunset, we wanted the 99333104580(RS Kinematic control arm) but there was no stock anywhere.

Meatball964

The RS KT arm is NLA per Porsche Germany. With no ETA given. I've been waiting for 1 1/2 years.
Unless they descide to make a run of them within the next month, I will be re bushing my OEM arm w/elephant RS sport bushings (next best thing).

Martin S.

seems to have worked well for me. Great workmanship too. Tarrett Engineering sells ERP, and they may have a version of their own, not clear on that. I got my KT Link from Tarrett Engineering.

Bill Verburg

Martin, there is a big difference between the ERP and Rennline mono-ball links and the factory rubber bushed links/

choices are
stock soft rubber are fine for the Doctor, Lawyer and Indian Chief that just uses the car around town, rear steer is amply evident, this is fine at most legal speeds but increasingly becomes obnoxious as suspension loads and speeds increase

sport/RS rubber tightens up the car and lot and makes the handling much more precise and sporting, rear steer is greatly reduced and is no longer at all intrusive even when used on track

mono-*****, remove all slop and rear steer the car has razor sharp handling, the only rubber is the tires so ride quality is poor, there is no rear steer at all, the car does what the driver tells it to(hopefully the driver knows what to do because the car won't help. The ERP and Rennline pieces have the additional advantage of turnbuckle adjustment, the car is no longer susceptible to losing alignment settings, either through eccentric migration or load

I wouldn't mix and match these 3 options
RS specific pieces will have a dab of blue paint on the forging and green on the rubber


RSR w/ mono-ball


Rennline upper rear w/ eccentric locks

I'd use booties on the mono-*****

chaoscreature

Thanks guys, now I need to spend more money

CaptainGSR

Yep, there goes a few grand... :-(

Thanks for all the great info. I'm gonna go the RS route.

Having to mess up my corner balancing/alignment yet again, is the most annoying part!

CaptainGSR

Question: are the inner rubber bushings the only difference between the stock and RS control arms? (A-arms and KT Arms)

pp000830

For street driven cars, if the part has no play and has functioned properly for the last 16+ years, why replace it? Whose to say it won't last another 16 years.

Andy