Rear Sway Bar Problem

[sagolfer]

I recently purchased a 86 Targa (my first Porsche). It's a bit of a fixer upper. The body is in good shape and the engine is strong (haven't had a leak down test yet). Interior needs a redo. I've been replacing stuff bit by bit including Bilstein shocks and struts (hugh difference in rid and handling), plugs, wires, dist cap, rotor, filters, oil, transmission fluid, hood struts and so on.

Here are some pics of the car

http://www.isanantonio.com/porsche/

PM me if you owned this car. I'd love to get a little history.

I suspect the car bottomed out at one time or another. The front AC condenser is smashed along with the toe hook. The wheels are Fuchs but with part numbers for previous models (911 361 020 44 & 43). Everything looks easy enough to fix.

But then I come to the Sway Bar. A write up from a mechanic back in 2000 stated that the owner complained of a knocking noise going over bumps. The mechanic wrote that the rear sway bar was previously repaired and was welded too close to the transmission. They fixed it by clamping on hose to the sway bar to minimize the noise. Any suggestions on how to fix? Can I get away with just putting a spacer on the bracket to lower the sway bar or should I remove the bracket weld in another?

Here are some pics:
http://www.isanantonio.com/porsche/swaybar/

Any input would be appreciated.

[JP911]

It's a shame that they did a lousy job repairing it. The "right" way to fix it would be to have the sway bar mounts cut off and have new ones welded in the correct position. A possible alternative would be to find the rear sway bar from a G50 Carrera (87-89 model years), which has a bend in the center section to clear the larger transmission housing. Your suggestion of using a spacer of some kind could work, but it will throw off the sway bar geometry (slightly).

[burgermeister]

I see no harm using a reasonable thickness spacer on both sides. The geometry change for a 10mm spacer would be the same as for a 10mm lowered suspension .... and noone is suggesting not lowering a car because it jacks up the sway bar geometry... in fact, the spacer would restore the factory geometry if the brackets were welded out of position.

Spacer seems like a much better plan than grinding the brackets off and welding new ones on.

[JP911]

Originally Posted by burgermeister

The geometry change for a 10mm spacer would be the same as for a 10mm lowered suspension .... and noone is suggesting not lowering a car because it jacks up the sway bar geometry... in fact, the spacer would restore the factory geometry if the brackets were welded out of position.

Spacer seems like a much better plan than grinding the brackets off and welding new ones on.

You're absolutely right about lowering and it's effect on the sway bar. Hence my use of the word "slightly".

The real issue with creating a spacer is going to be making one that will conform to the countoured sway bar bracket. The pre-78 bracket is flat, so a flat piece of steel with two holes would work, but after 78 the factory put an indentation in the bracket to accomodate a different bushing design that (conceivably) allows for more cushioning between the bar and the body.

[Quicksilver]

Originally Posted by JP911

You're absolutely right about lowering and it's effect on the sway bar. Hence my use of the word "slightly".

The real issue with creating a spacer is going to be making one that will conform to the countoured sway bar bracket. The pre-78 bracket is flat, so a flat piece of steel with two holes would work, but after 78 the factory put an indentation in the bracket to accomodate a different bushing design that (conceivably) allows for more cushioning between the bar and the body.

If it was my car I would space the thing out for the short term and plan to put the Wevo mount in the next time I was planning a more serious service.

[unclebilly]

Get a sway bar from a newer 930 (89). They are bent down in that section to clear the trans. This will solve your problems without cutting or welding.

[jester911]

The rear mounts cracking is very common especially if the car is tracked at all. (Ask me how I know) In my opinion doing anything short of having them cut off and new ones welded on properly is a bandaid on the problem.

Why not address the problem one time? As was suggested above go with the Wevo mounts and you won't need to deal with it again.

[sagolfer]

Thanks for the input guys.

A spacer would be ideal but I didn't notice the curve in the mount. I guess I would have to have something made to fit. Between the options of making the right shaped spacer or installing a bar from a G50 or 930 car, it would probably be best to just remove and replace the mount with the Wevo.

Let me know if anything else comes to mind.

[burgermeister]

If your spacer ends up 3/8" thick steel, I would not expect it to matter wether you match the indent or not. You'd have to shave whatever indent (outdent?) off the rubber.

If you want the indent on both sides (once for the bracket, once for the bushing), you could bend some 1/8 aluminum to fit and just stack 3 pieces - the thing is in compression, so structurally it will work just fine. Gets to be a pretty cheesy looking fix though.

Myself, I'd do the steel spacer fix to get 'er running until the brackets let go again, and then do the wevo part. Then again, my car needs lots of other work and I have limited time...

[don911]

I had the same issue when I added SRP #27 anti roll bars. The knock happend under hard acceleration and hard cornering. When the wevo mounts were installed, small spacers were added to keep the bar off the tranny.

[sagolfer]

And the current hoses clamped to the bar is not cheesy looking? :-)

This Porsche project is supposed to be a challenging, entertaining and relaxing hobby for me. I can't weld so I would hate to give up and pay someone to do it for me. Hmmm, If I had some blacksmithing skills, I would heat up some iron and bang it into the shape of a perfect spacer. How hard could that be? I'm off to find a blacksmith forum.

[sagolfer]

Don, did you make the spacers yourself or buy off the shelf?

[175K911]

One other thought for you- are you sure the trans mounts are OK and not old and tired causing the trans mount to sit a bit lower?

Regardless, if the pivot brackets were not repaired correctly, best to get it done the right way. Otherwise it'll just break again.

[sagolfer]

175k, I'll take a look at the transmission mounts. From what I can tell from the car's records, the problem was diagnosed by a mechanic back in 2000 (about 32,000 miles ago). The mechanic stated that he noticed previous work was done on the sway bar and the mounts were welded too close to the body making the sway bar too close to the transmission. He fixed it by attaching the hose and clamps ($30) to stop the noise. The transmission was rebuilt in 2001 (about 27,000 miles ago) but new mounts were not on the parts list.

[burgermeister]

You could always buy a welder!

Anyone can weld with a decent MIG (even me!). And it'll come in handy for all sorts of things.

Though this doesn't fit the "budget repair" bill, unless your tool budget is separate from the parts budget, sort of like a big corporation departmental setup ...

It's always best to listen to the voices in your head when buying a car IMO. Otherwise, they'll keep saying "I told you to get something else", and it gets annoying ...

[sagolfer]

I don't know about welding. Being in the Motor City it may come natural to you. It would be nice to do it myself but I can see some damage getting done with those tools. Not that I don't like new tools and they do have some pretty cool looking welding helmets (Darth Vader or goalie masks come to mind). I'm sure my wife would be impressed with me walking around the garage with one of those on. I'd have to make a list of all the things I could weld to try to justify the cost of the tools. I'd have to figure out what "MIG" means. Then there's arc welders, tig welders, spot welders, welding torches, plasma cutters, wire feed welders, welder generators (just looking at northertool.com).

[burgermeister]

Metal Inert Gas welding, probably the lowest skill welding process around, and the only one I am any good at. Comes in "flux core wire" or Gas Cylinder flavors. I'd recommend the Gas Cylinder flavor for auto body sheetmetal (those can also be used in "flux core" mode). Any decent welding shop is a great resource, and usually not more expensive than any internet vendor (though they often don't sell off-brand equipment)

Basically it's a 110 or 220V box with a couple of dials (wire speed and voltage). Usually has a chart that tells you what settings to use for what gage metal and what diameter welding wire, and what flow rate to set for the gas. Put on your auto-darkening helmet, point the gun, and press the trigger. Tweak the setting if necessary, and go to town. It's really that simple. I am a retarded monkey with 2 left hands when it comes to working on cars. My first valve adjustment took 9 hours, and it needed an adjustment immediately afterwards. This weekend it took me 2 hours to replace 1 stinkin' inside door handle! The list could go on... I make up for my lack of skill with sheer determination and excessive ignorance so I don't know what I'm getting into until it's too late.

Startup cost is likely in the $500 to $800 range, depending on how fancy you get. They can also be rented or, better yet, borrowed from friends (along with lessons!) for cases of beer or a gas cylinder refill ...

Check your front suspension pan to see if you will need it some more... that was my initiation anyhow.

[sagolfer]

Thanks for the info. I'll look into it.

[burgermeister]

Really though, what's so wrong with a bit of rubber hose clamped around the swaybar? If it fixes the problem (noise), and it's currently "free" (already installed), why not keep it?

[sagolfer]

Yes, you're probably right. Since there is no quick and easy way to fix it (like bolting on a spacer), I might as well wait until the current mounts crack then replace them.

I did find a couple of articles on MIG welding right here at Pelican in the Tech Info Center.