911 Carrera rear suspension

[ElAndrews]

Hello All! I'm new at the forum. I'm owner of a 1972 Westy and a MK6 GTI and as most of VW lovers I’m a Porsche enthusiast and about to become a Porsche Owner 😊… I’m looking to buy a 1984 911 Carrera Targa. My concern with the car is that when I was testing the car I kind of have to go through a bump and all of a sudden, I heard a noise and then the car's rear suspension went down very low to the floor. despite that, I was able to do a test run with no problems on the gear change, or accelerator cable stocked or any of stuff that will make me suspect about the rear torsion tube. A mechanic went to see the car and told me that the flooring, the front suspension and everything looked rust free, he even tried to stick a key into front suspension near the battery area and noticed the car was solid... the car has been on a garage since 2014 with occasional turning on, but no riding (owner’s words and permit on car’s’ windshield). Odometer says 54k on it although it has a push button to start the car.

Any advice on what might be the problem on the rear suspension? Is there any other problem that could lead to a fallen rear suspension on a 1984 Carrera? Any advice will be greatly appreciated!!!

Mechanic says that 1984 cars are rare to suffer from a broken torsion tube, mostly 930’s are the ones which suffers the most on this area.

Please let me know if that problem is a big problem on these Porsche models and I should be aware on not to buy the car, or if there is any other means that the rear suspension might fail which will have simple solution.

[Walt Fricke]

Yes, rare for the torsion tube to collapse. When it happens, it is usually due to rust. Surely this mechanic could just look to see if that had happened? The transmission, and the two rear banana arms are attached toward the center of the torsion tube. If the tube broke, I'd expect some difficulty shifting due to the transmission dropping some.

While you don't hear of it happening, if a torsion bar snapped the rear would drop. But much more on the side with the broken part. Was the drop one sided, or just as low on both sides? Perhaps the rear is riding on the bump stops on top of the shocks?

The ignition switch "start" position can fail over time. One way to deal with this is to install a push button to bypass the "start" position on the switch. Works just fine.

[HarryD]

What did the mechanic say about the rear suspension. I would assume you told him of your concern and he would verify of things are ok.

Was the mechanic who looked a the car one that specializes in air cooled Porsches?

[Bill Douglas]

Factor it into the price you would pay.

As long as the body is not rusty and it's a nice and tidy (un F' around with) looking car with a good engine... It could be fun!!!

[roblav]

Broken Torsion Tube is very, very rare in later cars. Quite common in 65-73 cars in the Northeast.

Your test run car may have just broken a torsion bar.

I remember back in the late 70's sitting at the kitchen table with my father. All of a sudden, we heard a loud "pop" from the driveway. A front torsion bar snapped on the 914... while just sitting there.

[Walt Fricke]

If a torsion bar broke, you should be able (or the current owner should be able) to get a used one dirt cheap. Most owners of 911 who get bitten by the track driving or autocross bug end up installing stiffer torsion bars. The old ones sit in garages and basements, as there isn't really a market for them.

Replacing a rear torsion bar requires removing the rubber strip along the rocker panel, and then removing the separate rocker panel (horizontal strip under the door)), and then the oval plug back in front of the rear fender. Then, after disassembling some of the rear suspension, the old bar can be removed, a new one installed, things put back together, and the car aligned. This is not a trifling expense, even assuming there are no problems getting the inner broken piece out. Which underlines the virtue of the comments which suggest you get the current owner to pay for the repairs, or else discount the buying price by the cost estimate you have gotten from a local Porsche dealer or independent shop for the fix.

[ElAndrews]

thank you guys for the responses I'll definetly look at those things the next time i see the car. As for the price i tink is fair considering the conditions of the car, aside from the rear suspension problem. it has some leaks, but the mechanic recomends to change the oil lines and put the car to good use before messing with more stuff (hard core stuff)... If i purchase the car that will be the way to go! and yes, I'll check the shift lever into al gears just to make sure ir engages through all of them. what would be a price range for a car like that? just wondering...

Thanks again!

[Shaun @ Tru6]

From your description, the tube didn't break, the torsion bar did. Rare but it happens and you don't know what's in there. Years ago Sway A Way bars were breaking on a regular basis. As long as the tube is OK, this is a great negotiating point similar to years ago I tested a 73 that was splashing gas everywhere with a broken line. Sellers just want the car gone sometimes when things like this happen.

[ElAndrews]

here are some photos of the car...

[RWebb]

torsion bar goes inside the outlined tube in front of this diagram:





Yours may now look like this:

[McLaren-TAG]

The weight of that horrendous looking wing must be what broke the torsion bar.

[Walt Fricke]

Now now - that's a 993 wing, at least in style. I can see why he is interested in the car, though I admit to being partial to Guards Red. It photographs well. The wing does stand out, though, doesn't it.

[175K911]

Unless those pictures were taken before the test drive, sure doesn’t look like it’s got a broken torsion bar.

[Bill Verburg]

Originally Posted by Walt Fricke

Now now - that's a 993 wing, at least in style. I can see why he is interested in the car, though I admit to being partial to Guards Red. It photographs well. The wing does stand out, though, doesn't it.

It's actually a 964 3.8Rs style wing and I agree it doesn't belong on that car

[ElAndrews]

I know... looks horrible, the good thing is that the original whale tale (which he also got) looks like new! That will be the first mod to the car... ��

Thanks for your inputs!

Yes @175K911. Those pics were before the incident...

Mclaren-TAG ������


What you think is a proper valie for a car like that? I’m kind of curious about that...

[ElAndrews]

Proper value***

I just figured out i have to use the emojis on the forum instead of the ones on my phone...

[McLaren-TAG]

Value and price are two separate things. It depends on what you're looking for and a car like that is bound to have a lot of TLC needs. I know prices went up crazy and have cooled off again with people now willing to sell decent driver quality cars that need some loving for a fair price instead of the frenzy bubble induced prices being asked a few years ago.

It's clearly a car that would be a candidate for a full mechanical go through and if the engine is strong, would give you a lot of smiles per mile. But do yourself a favor if you really want to buy the car, don't trust your mechanic, talk to someone in your local PCA club and ask them for a mechanic in the area that will do a pre purchase inspection.

What is it that you want to have? How much work can you do yourself and what's the budget for not only the price of the car but also for getting it to a place where it can be a reliable driver until you figure out what it is that you want to do with it long term.

From what you say it sounds like it has the potential to be a solid driver without sinking in too much money into it. But get the PPI and then negotiate the price from there.

[ElAndrews]

Thanks McLaren-TAG for the input! I forgot to mention that the mechanic is focused on air cooled Porsche and he also do bodyworks for those cars. Someone else who is a BMW mechanic recommended him. His advice was that the car was a bit expensive, but it was a solid car. Honestly, as you well say, there are lot’s of cars with high price tag and little value. I saw an SC at 28k and it was a total waste of money: lots of rust, lots of oil, destroyed interiors..... this one is far behind that price tag... And way much better car.

[ElAndrews]

Another quick question... does anybody knows the internal diameter of the torsion tube. Just to know how to reach the Tbar in case is broken deep down.

Thanks!

[Walt Fricke]

It is at least 36mm, because I have a bar that big in mine, and it is the largest which will fit. However, for the main tube you can just measure its OD under the car, and subtract a bit for wall thickness.

Let's hope just one bar is broken. That way (this does have the 915 transmission? It's an 84 or 5?) you (or your mechanic) can remove the good bar on the other side, and use a long rod to punch out the splined stub on the broken side. Once that is loose in the torsion tube, a magnet on a rod will easily pull the broken part out.

If both are broken, getting the stubs out could be a significant issue. It is possible to cut out the torsion tube where it is exposed, and weld a replacement in. But that's major surgery.

Maybe someone has a better idea for a two bars broken situation.