New tires = Surfboard affect

Techspert · 04-06-2005, 05:52 AM

Problem:

I have an '85 911 Targa that was sitting up for the past 6 months. I very recently replaced all 4 tires with new ones but immediately noticed the car pulls to the left upon acceleration at takeoff and then straigtens (prior to putting the car in storage, I only noticed a slight pull to the left which I felt was an alignment problem because the steering wheel was not completely straight). While driving, the car pulls to the left and gives a wavy unstable effect (almost a side-to-side motion). I don't believe I have a lot of play in the steering wheel. I have also noticed that I am feeling all bumps in the road and even pulling into my driveway is like driving on the Dukes of Hazard.

What could the problem(s) be? I was told shocks/struts probably need replacing. I've also been told to tried turbo tie rods and there has even been mention of bad bushings. If it is a bushings issue, which ones would most likely be the culprit? How difficult would you guys rate (1-10 in difficulty) for replacement on: rear shocks, struts, tie rods, bushings? My dad has a lot of mechanical experience with American, Japanese and Audi cars but has never attempted to work on my Porsche. I'm trying to save money so any help will be greatly appreciated.

The car has 185k miles. I'm not sure if those parts have ever been replaced. I've owned the car since '97. The tires Fulda Z-rated are the correct size, balanced and mounted properly.

Also, please recommend a book for the aforementioned repair jobs.

Venetian · 04-06-2005, 06:06 AM

I think it takes a few hundred miles for the tires to "break in". When I put new tires on mine they seemed a lot "grabbier" at first. Either I got used to it or they got better with mileage.

Wil Ferch · 04-06-2005, 06:10 AM

I too have found a necessary break-in period.....this can last up to 500-1000 miles before the sensation all goes away. Don't forget, the new tires are riding "on stilts"...new rubber blocks.

But...the right/left jinks posted here would have me concerned that yet another problem ( alignment ?) exists.... ??

Wil

stefang · 04-06-2005, 06:20 AM

Shocks & Struts (inserts) are easy. Maybe a 2-3 (probably a 1 for an experienced mechanic). Though he'll appreciate having to practically crawl into the engine compartment to get at the shock mounts. The joys of working on P-cars

For instruction use the tech articles on this site, Wayne's book (101 projects) and Bentley.

I'll third the tire breaking in thing. Going through the same period right now.

Stef

Techspert · 04-06-2005, 06:53 AM

I'm definitely going to get the 101 Projects book. I've never heard of the tire break-in period thing but I'll consider that. Any other thoughts?

bigchillcar · bigchillcar's Garage

my uncle bought four new tires a couple months back and the ride was terrible..turns out one of the 'new' tires was out of round from the factory and had to be replaced. happens sometimes..were they balanced?
ryan

Techspert · 04-06-2005, 11:00 AM

Quote:

Originally posted by bigchillcar
my uncle bought four new tires a couple months back and the ride was terrible..turns out one of the 'new' tires was out of round from the factory and had to be replaced. happens sometimes..were they balanced?
ryan

Yes, they were balanced. I need to take a look at the weights and see if a lot were required. That would probably be indicative of an out-of-round tire. It doesn't feel like a balance issue though because I don't feel any vibration from the front or rear, just an unstable side-to-side feel when accelerating.

911mot · 911mot's Garage

Have you checked the pressures?

buster73 · buster73's Garage

Check tire pressure and alignment first. I don't see how new tires should be a reason for the car to pull to one side. New tires certainly take some break-in time to wear off the somewhat slippery surface layer, but this should not take more than 200 mi.

greglepore · 04-06-2005, 03:19 PM

Fuldas have a so-so reputation-could be a bad tire; at 180k you surely need shocks and likely bushings. Its night and day once they're changed and the car aligned.

Shocks and struts are easy-anyone with the ability to turn a wrench can do them-tie rods harder, but certainly a diy job, bushings require about a full day each front and rear, but aren't difficult per se. If you're going to do bushings and tie rods, I'd do them together so as to only have one alignment to deal with.

Wil Ferch · 05:06 PM

For the record.....my S0-3's required close to 700-1000 miles before I felt comfortable enough to get my car on the track........ very unsettling feeling from the rear. Afterwards....bliss.

Wil

EDIT...OOps...meant to say SO-2's.....

NoLift911 · 04-07-2005, 06:53 AM

All of this stuff is great advice but before you go chasing shocks/alignment and other expensive suspension components remember the cause - which you stated:

"I very recently replaced all 4 tires with new ones but immediately noticed the car pulls to the left upon acceleration at takeoff and then straigtens (prior to putting the car in storage, I only noticed a slight pull to the left which I felt was an alignment problem because the steering wheel was not completely straight)."

If everything was fine before and now it is not it would be the = starts with a T and ends with an S. I, R, E in the middle. As the culprit

I find that some folks change one thing and when not satisfied with the result chase thier tales on the cause - which in this case you have the cause. New tires do not make shocks bad, bushings, tie rods etc. bad either.

On the other hand you could have had a set of old tires that had a bad alignment worn into them - your new tires simply make the issue come to light.

I have had sets of tires that simply do not play well with certain cars - My advice is re check pressures, alignment and then see what happens after a few hundred miles to get used to them. Not sure about the "break in" theory.

Make sure you are within your window to return them should you choose to do so and go with another brand. Like I said keep it simple - the problem is probably the tires. Maybe try another brand or swap out another set with someone elses car to see if you get the same undesirable effects.

-Jeff

kycarguy 935 · 04-07-2005, 08:28 AM

I agree with some others checking the pressure first. It depends on the severity of the problem too. If not too bad then drive it awhile for new tire break in period otherwise check for suspension related issues.

stlrj · 04-07-2005, 01:53 PM

Quote:

(almost a side-to-side motion)

CV joints gone bad?

Techspert · 04-26-2005, 05:12 AM

Quote:

Originally posted by nolift911
All of this stuff is great advice but before you go chasing shocks/alignment and other expensive suspension components remember the cause - which you stated:

"I very recently replaced all 4 tires with new ones but immediately noticed the car pulls to the left upon acceleration at takeoff and then straigtens (prior to putting the car in storage, I only noticed a slight pull to the left which I felt was an alignment problem because the steering wheel was not completely straight)."

If everything was fine before and now it is not it would be the = starts with a T and ends with an S. I, R, E in the middle. As the culprit

I find that some folks change one thing and when not satisfied with the result chase thier tales on the cause - which in this case you have the cause. New tires do not make shocks bad, bushings, tie rods etc. bad either...

-Jeff

You were certainly right. The j@ck@$$3$ at NTB on Cobb Parkway in Marietta, GA installed 225/50 on the driver rr and 225/55 on the passenger lr !!!

I was pissed! They corrected the problem and now the the car drives great!

I won't be going back there again...

I was told the Fuldas are not the best and are usually out of round but I put so few miles on it that I thought it really didn't matter. You get what you pay for. I'm gonna see if I can swap them out for some Kumho or Falkens. Those should be a little better and not much more expensive.