regular but not constant shudder in steering wheel

[Austin]

I did some searching of the site before posting a new thread, but the vibration/shudder issues were all a little different from mine...

I've got a regular but not constant shudder in my steering wheel that begins to be felt just under 50mph. When I say regular but not constant I mean that it vibrates for a half second, is smooth for a half second, vibrates for a half second, smooth, vibrate, smooth, vibe, etc.

A little background, the car was wrecked some years ago and sat on a flat tire for most (all?) of that time. As a result the tire got "cupped" or something. I don't know if that's the culprit or not, but I thought it wouldn't hurt to mention.

I bought the car from Huck, who had the tires balanced before I came to pick it up (because he's a great guy and thought it might just be a balancing issue). Unfortunately it didn't do the trick. The fact that it's regular but not constant is what also confirms to me that it's not a balancing issue.

One thing I was thinking was that maybe the one tire being flat for so long has caused it to wear oddly and have a slightly different diameter than the other 3, and therefore causing my AWD to get squirrely. My concern there obviously is not the cost of new tires but the cost of a new tranny!

Does that sound like a valid concern? Does it sound like a new set of tires would fix it (they've got some tread left, but a new set wouldn't hurt)? I'm about to make the 1200 mile round trip from JAX, FL to the Dragon and don't want to ruin my car along the way.

Ideas? Suggestions? Donations?

[huck369]

My guess would be a weak strut....
But if I were ready to spend on tires, that would rule them out, and something you'll have to replace eventually anyway (could put the old SVX tires on the XT6)

[Austin]

wow - really?!

I never would have guessed that. Then again, I don't know much about cars.

So the strut just like wobbles or something every half second or so? I'm not sure if I get it.

[92snowmachine]

if the strut is week then it won't hold the tire to the ground when it hits bumps, so you get high and low spots on your tire. run your hand across the tires to see if they feel lumpy or feathered.

[Austin]

hmmm... I'll have to try that.

I live in FL with flat roads, flat everything, (well, unless you go to the beach ) and the roads are generally not too bumpy. At least they're not consistently bumpy every half second... on every road including the highway.

Still, I'll take a look at it. probably not a bad place to start. I'll also start pricing struts I guess.

[decline]

my car shudders at highway speeds and especially around bends. The consensus among my mechanic and a few others seems to be the front axels are beat and in need of replacement. Theyre clickin an popin in low speed turning situations such as parking lots also
Unfortunatly thats on the back burner until I get my hard/non start issue resolved, buts just a suggestion

[benebob]

How's the track rod end look?

[svxum2teal]

I would also tend to think that it might not not be a tire issue as the others have mentioned... but I thought that if you wanted to try to test if it is a single tire problem you might be able to test this by using your spare once in each position (I suppose just the front two) then doing a road test. I believe the spare is probably not supposed to go 50 (at least as recommended (do this on your own liability... )) though I have used mine fine for short periods at highway speed... Make sure it is in good shape though! Of course who knows, but the spare may case some other shuddering?

I hope this helps.

Mitch

[Austin]

Well, the last few days my left front tire has been leaking air and I've had to inflate it every other day or just even after having driven 100 miles. The tires still had plenty of tread but I knew one was "bad" (it had sat deflated for a couple of years when the car was wrecked) although it didn't look it. That tire did have a plug in it I recently discovered and that was definitely where it was leaking slowly, but it seems that slow leak had very recently gotten much worse.

Long story short: I went and got new tires today and it seems to have solved two big problems I was having:

a.) it got rid of the shudder - period
2.) it seems to have solved my engine surging (thought it was the TPS)

I'm not completely sure about number 2, but a.) was my main issue in this post and seems to be gone. WOO-HOO!!!

I leave for the Dragon tomorrow (1,200 mile round trip) so we'll see about the surging thing.

Now... while the car was up on the lift the guy noticed a bent rim (very minor - doesn't seem to be affecting the ride at all) and right next to it he noticed THIS.

[Earthworm]

I think if both front tires are out of balance by about the same amount the car will sometimes be "in-phase" and there will be no vibration. The new tires would be balanced and that's my theory why the shudder has disappeared. Same can apply to the rear tires except you would feel that in your seat.

[Austin]

ding-ding-ding!!! Good answer! I like it. That makes sense to me (not that the other answers didn't make sense either, based on the information available at the time, but now that I know the tires were the culprit...).

So far today I've driven about 300 miles and it's vibration free and as I said the surging seems to have disappeared too.