Odd noise from front of car

[Reaper450128]

OK, I have an odd noise coming from the front part of the car. It sounds something like a train, a sort of CLUNK-clunk-clunk-clunk that repeats, more rapidly the faster the car goes. It gets louder under acceleration, and turns into a sort of buzz when I take my foot off the pedal, a sound a lot like a big truck when it downshifts. Any ideas? The car doesn't show any other signs of a problem other than the vibration that comes from whatever causes the noise.

Before anyone tells me to use the search feature, I did, and it wasn't any of the things I found as possible explanations. It mostly seems to come from the drivers side, so I checked the locator pin on the caliper, tightened it down a turn or two. Checked the boots on all the CVs, all of them are fully intact. I tried spinning the front wheels while the front end was jacked up, but it wouldn't make the noise then, though that might have to do with the fact that the wheels spin in opposite directions when you do that. It doesn't happen when I rev the engine, so its something in the drivetrain. It sort of gives me the impression by the rate at which it occurs and the noise and vibration associated with it that its something getting in the way of a rotating component, like the wheels. Could it still be the CV joints even though the boots are intact?

Just cause the boots are intact does not mean the CV joints are not worn out. The way you describe it does not sould like a CV joint if it is a buzzing sound clunking sound, but mostly because your noises comes from straight line driving. The DOJ could make a clunk under load in a straight line, check them out.

[Reaper450128]

First, DOJ? Forgive me, but I'm not familiar with that abbreviation.

Second, you said the DOJ could make a clunk under load in a straight line, what if it does while turning as well?

My first post was kind of rushed because I was heading off for a class, if there's any info I might have left out, please let me know.

A couple of things I forgot to mention:
1. I tried dropping it into neutral while it was moving, the noise was unaffected.
2. It makes the noise anytime over about 10-15MPH, straight-line movement or turning.
3. The "truck downshift" noise doesn't occur until around 40MPH, under that the noise stays the same when I release the throttle pedal.
4. I've got about 114,000 miles on the car. The driver's side axle was supposedly worked on by the mechanic I bought the car from before he sold it to me, about 5000 miles ago. I believe the noise is originating from that same area now, but I'm not 100% certain.

And a couple more questions:
1. Can I drive it safely like this?
2. I noticed one more possibility of it being the center caps on the wheels, is this true?

[mbtoloczko]

Originally posted by Reaper450128
First, DOJ? Forgive me, but I'm not familiar with that abbreviation.

...

Maybe its a front axle seal?

http://www.carsurvey.org/review_44246.html

[TomsSVX]

i have recently had a similar problem. The front differential. the noise is the fact that your bearings are probobly shot and it's destoryed ur gears. this means ull probobly have to replace your pinion and ring gear including ll new bearings on the carrirer and on the pinion. I am not trying to tell you this is what it is, if u want put the car up on jacks (supported very well) get in it and start it up, put it in drive and get the speedo up to 30-50 mph. while you are doing this, use a very long screwdriver or any long metal shaft and put it up against your converter case. this is the case after the engine but before the transmission. Listen for the noise inside that. get back to me with your results

[Reaper450128]

i have recently had a similar problem. The front differential. the noise is the fact that your bearings are probobly shot and it's destoryed ur gears. this means ull probobly have to replace your pinion and ring gear including ll new bearings on the carrirer and on the pinion. I am not trying to tell you this is what it is, if u want put the car up on jacks (supported very well) get in it and start it up, put it in drive and get the speedo up to 30-50 mph. while you are doing this, use a very long screwdriver or any long metal shaft and put it up against your converter case. this is the case after the engine but before the transmission. Listen for the noise inside that. get back to me with your results

I've been toying with the idea of doing this, but I'd feel better if I had a more stable place to support it than a gravel driveway in order to get it up on 4 jack stands. How's about this: if I get the front up on jack stands and use the FWD fuse, can I safely perform this test? I've heard conflicting reports about what the FWD mode actually is on the USDM SVXs, so I'm not sure how safe it would be to do it like that.

I was hoping it wouldn't be something like the front diff or transmission, so I hope this test comes up negative.

Did the problem occur suddenly for you when your diff broke? This is one of the things that really thrown me about this, I was driving home from work on Monday morning when it happened. I dropped one of my coworkers off at his place about 15min from work, and about 5 min away from my place. I didn't notice anything on the way to his place, but about 2 minutes away from there, I noticed it after I turned onto a road and started accelerating somewhat hard. As soon as I felt it, I backed off the pedal, and it went away. I came to the next light I had to turn at, and it came back as I was turning and then it didn't seem to want to go away. I put it up on jack stands after I got home, and I couldn't see anything visibly wrong. My coworker didn't hear anything as I left his place, so it started sometime after that. Does this sound similar to how your problem manifested itself?

[Reaper450128]

Actually, Tom, I just went to search for your post on your problem, and I have a feeling I'm in an entirely different boat from you. There is no whining noise, never was, and also my car is AWD, whereas yours is FWD (not sure if it really makes a difference, but I think it does). Not to say that there's no way my problem is the same as yours, but somehow (and with great hope I say this) I don't think it is.

[TomsSVX]

well thats just thing, i had a whine at first for a long time, only when i was accelrating, then 2 weeks ago i was driving my girlfriend home and i heard a slight knocking noise as i started out of a light. i turned off the stereo and the heat and listened closer. I had no idea what it was so i kept driving but it got worse as i drove. By the time i limped it home the knock was very loud and did it throughout acceleration and downshift. i ripped the trans out to see my pinion was almost comletely gone. I am just using my experience as a reference cuz it sounds similar. Also try and get ur car up on a frame lift at a garage somewhere, i had my buddy at a trans shop do it when i first heard the whining. They imideiately told me it was the diff. you will need 2 people, one for the gas and one to listen to the converter housing/diff. enclosure. while you are getting dirty check the diff fluid on the passenger side and look to see if there is enough. another thing is to drain the diff fluid and look for shavings. and fill it w/ new 80w 90 gear lubricant. get back to me w/ conclusions

The front diff is a possibilty, I just wanted to avoid saying that right off the bat. If your car is AWD, put the fuse in to make it FWD and get the front end of the ground and listen to it.

As far as a DOJ that is the inner joint, the outter joint is a CVJ.

[Reaper450128]

Well, in the couple of test drives I've done since then, it hasn't gotten any worse, so hopefully that's a good sign.

As long as I won't be in any danger while doing the test, I'll try to do it tomorrow morning if I can get a buddy over to help me with it (although I suppose at those speeds I could also use the cruise control for the gas). Now, I'm listening for a noise in what part, the converter case? I assume that means the torque converter case? I'm guessing based on that that its where the front diff is as well?

Just out of curiosity, what does DOJ stand for in this context?

[TomsSVX]

the converter case is the middle of the three pans, you have your engine oil pan, you converter case and then you have your flat transmission pan. nyou just want to place a long driver up to the case and listen for a bad mess or to see if the sound is indeed comming from there

[Reaper450128]

Against my own better judgement, I gave it a good long test drive today (roughly 20min, 40-50MPH primarily). I started to notice a new noise, and got a good chance to listen to and feel the old noises and vibrations. So, add a scraping noise to the mix now. I'm starting to think its definately bearings, possibly wheel bearings in addition to CVJs. The clunk is quite noticeable in the throttle pedal, and quiets considerably when I'm off throttle and as it speeds up above 40MPH. Does this make any difference in the diagnosis?

I was unable to check the fluid today, or do the test you suggested, I'll try again tomorrow.

[Reaper450128]

Took it by a shop today, had them take a listen and perform the suggested test up on a lift. The noise isn't coming from the differential, its coming from the transmission. The tech said he could feel the thud quite heavily in the transmission pan itself. While this shop has no particular experience with SVXs, they did install this very transmission for me about 5000 miles ago.

As it is now, the vibration has made it undriveable. I was a little concerened I wouldn't make it home from the shop, and thats only a 10 min drive. So, I'm going to rebuild my original transmission (its still in a box in the garage), and trade them out again. I currently intend on purchasing the Level 10 Stage 2 or 3 PTS Kit (still trying to decde, the price difference is fairly minor), and rebuilding it myself in my basement. I will get the valve body mod done by them in a month or two when the cash is availiable. I'll check out the diff while the whole thing is off the car, and I'll rip apart the tranny afterwards to see what went wrong with this one. Of all the stories I've heard on the group here, this is the first 4EAT I've seen die while still capable of shifting to all gears, so it makes me wonder...

Here's a thought. (Unless I missed this in an earlier post)

How about the carrier bearing for the rear drive axle?

Just a thought. AH! Now it's gone. Whew.


Randy ii

[Reaper450128]

The thought occured to me as well, but I dismissed it when installing the FWD fuse didn't fix it. The noise goes away when I close the throttle (ie no engine load, no noise) under normal circumstances, so with the rear wheels being unpowered when the fuse is in, the noise should go away then, I think.