No Travel In Front Suspension

[DienstXIV]

Hi Everyone,

I have a very strange problem happening to my stock 1975 Porsche 911 S that I am hoping someone here can help me solve. The front suspension has no travel. Literally it won't go down an inch. After working on the rear brakes and fuel system for a few months I took the car out for a test drive and the front suspension felt very stiff and rough. I tried pushing down on the suspension and no travel whatsoever. I jacked up the car and disconnected the front shock and compressed the shock and it did compress all the way. With the car on jack stands if I try and jack up the front bake rotor the whole car just raises off the jack stands and the suspension won't move even with the shock disconnected.

I took out the left front torsion bar, inspected it, cleaned it and greased it. I thought that maybe the torsion bar was rusted inside the A-arm or something but it was fine. My torsion bars are stock 19mm by the way I measured one. I put everything back together last night and the suspension had travel again and on both sides even! It was great and everything was good!

Today I went to go take the car for a spin before I played with the front suspension ride height and once again the suspension has zero travel. How can this happen?

Any help is much appreciated!

Cheers!
Alex

[fanaudical]

Is the front lowered at all? Is it too low (all the suspension travel been removed)?

[DienstXIV]

Originally Posted by fanaudical

Is the front lowered at all? Is it too low (all the suspension travel been removed)?

The suspension is stock US height so it's pretty high at the moment.

[dannobee]

Did you disconnect the sway bar when you did this test?

[stownsen914]

What size torsion bars are they? The larger aftermarket sizes can be seriously stiff.

[75 911s]

Reading what you wrote, is it possible for the shock to be binding in some manner? Just thinking about this logically, the T-Bar was inspected and operational, I don't see how it could bind, but the shock is inside the strut and hidden. How old are your front shocks? I realize you were able to compress it, but perhaps something happens to lock it up somehow. I've never heard of this so following with interest.

[ryans65]

Over the years I've had three shocks on various vehicles completely sieze up randomly, one would not compress or rebound, another one would compress but not release. It's odd but happens.

[DienstXIV]

Originally Posted by dannobee

Did you disconnect the sway bar when you did this test?

I did not disconnect the sway bar, should I? What affect would that have on the test?

[DienstXIV]

Originally Posted by stownsen914

What size torsion bars are they? The larger aftermarket sizes can be seriously stiff.

The torsion bars are stock 19mm. Once I got everything together the suspension had travel again in the garage but once I pulled the car out of the garage the next day the suspension was all locked up again. So strange and frustrating!

[DienstXIV]

Originally Posted by 75 911s

Reading what you wrote, is it possible for the shock to be binding in some manner? Just thinking about this logically, the T-Bar was inspected and operational, I don't see how it could bind, but the shock is inside the strut and hidden. How old are your front shocks? I realize you were able to compress it, but perhaps something happens to lock it up somehow. I've never heard of this so following with interest.

My shocks do look very old but when I was able to get everything working again the rebound was spot on. You did make me think of something though. To get the torsion bar out I had to remove the front mounting bolts on the A-arm. When I went to put everything back together it was very difficult to get the A-arm bolts back in because the holes wouldn't line up. I had to compress the bushings in the A-arm with some vice-grips in order to put in the front mounting bolts. I believe the holes not lining up is due to the fact that I had the front pan was replaced recently. Could the compressed stock rubber bushings really lock up my front suspension? Is the front end of a 75 Porsche 911 really that light? If this is the problem I could just make the slot on the front mounting location of the A-arm a little longer.

[bkreigsr]

Maybe the rubber bushings have turned to cement inside the control arms, and are cementing the a-arms in place.
You've inspected everything else.
Bill K

[Reiver]

^^^ if the rubber bushings collapse the T bars can bind on metal....when you cleaned them did you note wear/rubbing.
Have you changed out the bushings?

[turborat]

Are the tie-rods correctly position at the rack side? If they are non-turbo, they must be clocked correctly so the fork will articulate correctly. Of not, they will bind up the suspension travel.

[djpateman]

Probably not the cause in this case, however a broken torsion bar will permit no movement on it's side; but the car will appear to be lowered.

[HarryD]

Nothing to really add but this quote: “ Any suspension, no matter how poorly designed, can be made to work reasonably well if you just stop it from moving.”
Colin Chapman

[Walt Fricke]

The A arm moves in its two rubber bushes - front and rear. If, when you had the T bar out, you could move the A arm, it would be hard to concluded these bushes had turned to a sort of rubber JB Weld.

The strut's movement is in the ball joint and the shock tower bushing up top. It is a bit hard to see binding on either of these resisting the 750 or so pounds each side sees statically.

Disconnecting the sway bar (somewhat of a PITA? - maybe just unbolt its chassis holders?) might be worth it to try to be sure which side has the bind. This would allow you to isolate the sides.

You seem to think it is the left side which is binding? Is that because jacking the right side by the bottom of the strut (or rotor) shows motion, while doing that on the left shows none as you state?

You say this was with the shock disconnected. You mean you removed the nut up top, compressed the shock, and swung the strut out of the fender, as if to replace a shock? Or otherwise the top of the strut had no connection to the chassis? I can see why this would point to the A arm.

Are these Boge struts? I'm trying to think of how bump rubber could fail and cause a sort of intermittent lock up. The internal environment of a shock would seem to be pretty clean, no way really for grit to get in and mess up valving.

No way can I think of that stock diameter T bars could cause any of this - they are far away from the A arm tube's walls.

A puzzle for sure.

[HarryD]

For Ha-ha's, I went out to my 911 and tried to push down the front end. It barely moves. I know for a fact it works just fine so I am not worried.

A T-bar suspension does NOT bounce like a coil spring suspension.

[icarp]

front shocks are sitting on bump rubbers , cut off one and a half of the donuts
Very normal problem
Ian

[tobluforu]

Mine barely moves as well.

[Walt Fricke]

Years of pre-tech for DEs included checking shocks. You pushed down on the fender with all your weight, and then let it off all at once. If the shocks were good, the car would go back to ride height and stay there. If a shock was failing, there would be a little bouncing around as the car settled down. Yes, the car didn't go down much - especially with a stiff track suspension.

I interpret the problem here to be much more than stiff T bars or shocks. His are stock, and no mention that he changed shocks - which usually get looser with wear. When you jack a car up by a suspension member, the suspension member itself should move as the spring twists to take up the load.

If the car has been lowered rather a lot, then it might be the bump rubber, but that ought not to show up with the side jacked up and the front hub hanging down before a jack is added there - at full droop there should be no bump rubber interference.