Should I get 2 or 4 new tires?

Hi all--

I've reviewed some of the threads but I'd like to revisit a tire topic. Bear with me if this seems like a long post:

- I have -- and love-- my 99 MT Subaru Forester S. I replaced the stock tires with 4 Kelly Navigator Golds ~50,000mi and I have ~77,000 miles on the car now.

'bout 3 months ago I struck a rock on the highway, which tore the sidewall of a front tire and dinged its wheel to the point that they both needed to be replaced. The local tire dealer recommended 2 new tires (same Kelly's), which I bought and had them mounted to the front axle.

More recently I've noticed that there's a "clunking" noise/sensation from the front wheel wells (you can feel it in the steering wheel/stick shift), only when I'm slowly turning the car with my steering wheel turned to the extreme right or left. The feeling's only intermittent and fortunately's not present with regular driving and turning at intersections.

I brought my Subie in for an inspection and they recommended I buy 2 new tires first, before they try to do a major transmission diagnostic job.

Can the "clunk" be blamed on a tread mismatch? The newer tires have ~2,000 highway miles on them and I'm pretty sure my alignment's fine. I can get a tread gague if that'll help people's answers. Thanks in advance!

-b

Reply to
skibum
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"skibum" wrote in news:1115311396.358642.178800 @o13g2000cwo.googlegroups.com:

Subaru generally recommends you replace all 4 tires unless the difference in circumference is less than a 1/4". More info here:

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Reply to
Fuzzy Logic

I'm no expert, but your problem sounds more like a bad CV joint or steering linkage problem. You can crawl under the car and visually inspect the CV joints with nothing more than a flashlight. They are the black rubber bellows-like things that fit around each end of the halfshafts going between the wheels and the transaxle. If any of the boots are torn, they will quicky allow dirt to get into the joints and destroy them.

While you're under there, look for any broken or rubbing steering or suspension gear.

Reply to
Jim Stewart

On Thu, 05 May 2005 16:43:16 GMT, "skibum" wrote in news: snipped-for-privacy@o13g2000cwo.googlegroups.com:

Bad CV joint. Classic symptoms. It will get worse. It may have started when your CV joint boot was nicked at the same time your tire damage occurred, allowing water and dirt to contaminate the CV joint.

Reply to
Juan Vado

Hi,

As Jim said, check those CV joints--the low speed "clunk" w/ wheel close to lock at one end or another is one of the "classic" symptoms of a joint going bad. If the boots AREN'T torn, you're probably due for new ones by now if they haven't been replaced before, with attendant cleaning and regreasing of the joints. If a boot IS torn, you may find it cheaper in the long run to swap out the complete axle for a remanufactured one (go Subie OEM on that--voice of experience! The extra cost is worth it.) You might also want to jack the front wheels up and check for any looseness in the wheel bearings in addition to checking everything else suspension related. There can also be some clunking related to shocks/struts, but IME it's not related to wheel position like the noise a sick CV joint exhibits.

On the tires, I'd put them low on the list of "possible suspects," but you might want to rotate your new ones to the rear and see if the noise is still there. And on the subject of tires, be sure to check the torque on all your wheels. If you've got alloys, lugnuts can come loose more easily than they do on steel, so that's yet another slight possibility.

Another poster mentioned Subaru's 1/4" circumference difference figure. This has been discussed before, and I'm not sure I'm yet convinced they actually meant circumference or diameter (as in missprint?) If you do the math, that's only allowing a little more than 1/16" difference in diameter! I'm skeptical of that figure--it just doesn't seem to be a reasonable real world number.

Hope you find the problem easily!

Rick

Reply to
Rick Courtright

It seems to be a one size fits all description. The mechanical diff in his manual transmission car should be OK. I think the big problem is how the more sophiticated Subaru electronic AWD drive systems can go batty (working overtime) when they sense the wheels aren't turning at the same rate.

Reply to
y_p_w

Thanks gang--

I took a look a the CV boots and they seem intact, but maybe there are some cracks that I missed. I'll bring them back to a local shop to get a 2nd opinion about the clunk.

Reply to
skibum

My 85 Subaru doesn't have a front/read differential, and had a lot of trouble getting out of 4WD mode when I bought two of the same model tires a year later. Replacing all four at the same time fixed the problem.

Reply to
Guy Macon

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