Brett San Diego

My car (1978 911SC) sits at what looks close to euro ride height in the rear, but the front doesn't appear lowered at all. I'm wondering if there are old (maybe original) torsion bars in the rear that are simply sagging. I don't have any history on the car, so I have no idea if the rear bars were ever changed. It would seem odd for an owner to lower the rear and not to do the front, too, especially since the front is so much easier.

Thanks,
Brett

84_Carrera

Mine strikes me the same way Brett; 84 cab, stock original suspension.

bbh03

What kind of mileage? They can wear out but I don't know if it will cause sagging...

Brett San Diego

46,000 miles.

Brett

bbh03

A little young for the torsion bars to be shot, IMO.

Brett San Diego

But, if they're original, they're 27 years old. So I'm wondering more about fatigue over time rather than mileage. And should the bars be replaced after so many years regardless of mileage? Or better question, what are the indications, in general, that torsion bars should be replaced?

Thanks for your comments, bbh.
Brett

bbh03

True, and good questions. I don't know - I'm sure someone else here can answer though. For reference, my '78 has 150k and does not show any signs of sag. I do not know if they are original or not, but they do not look as if they have been replaced any time recently.

r911

take them out & inspect for any cracks, spalling, rust, etc. -- if ok, re-grease & install

or get lighter/stiffer ones

your real problem is the ol rubber in the brake hoses, suspension

lots of info if you search here & pelican

imcarthur

Rather than the torsion bars, have you looked at your springplate bushings? If they are original, they WILL be worn & thinner than new. This will lower the rear . . .

Ian

Only 62K on these . . .

Steve Weiner-Rennsport Systems

Hi:

Generally speaking; torsion bars don't sag. Over the past 30 years, I've seen some broken ones but the majority of cases where the ride height has settled, its usually a bushing issue just like Ian pointed out.

German rubber has always been notorious for not being of the same longevity as US products and the OEM A-arm/Spring plate bushings do sag over time.

After 15-10 years, its time to replace them with one of the several options available.

bbh03

What are the options besides OEM?

Steve Weiner-Rennsport Systems

1) Elephant Racing's Poly-Bronze (fitted with zerk fittings and the preferred item)

2) Weltmeister's Polyurethane (MUST be machined to fit and will require periodic maintenance in the future)

3) Neatrix (rear only)

Ride quality & handling are improved with the Poly-Bronze ones over polyurethane or OEM.

r911

also Wevo makes a compete replacement for the whole thing -- not cheap, high quality

bbh03

I will be looking for a race setup once the engine is overhauled. Thanks for the info.

Steve Weiner-Rennsport Systems

If its a race car and you are using coilovers, there is nothing better than the ERP 935 front suspension and 935 spring plates.

If you are using T-bars, then I'd use Poly-bronze up front and the new Wevo rear spring plates.