Drivetrain Odd Noise/vibration At Low Speeds

Discussion in '1994 - 1995 Specific Tech' started by 02 281 GT, Oct 11, 2012.


  1. 02 281 GT

    02 281 GT Active Member

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    I've recently noticed that my car has been experiencing a low vibration accompanied by a grinding/growling noise at low speeds (between 3 and 10mph). It sounds/feels like it's coming from the rear of the car rather than the front. The only suspension mods I have are H&R springs and Tokico shocks. I have Foose wheels installed that I drove on for a while before I realized I needed hubcentric rings (they were causing vibrations at high speeds). It's been a little while since I've had the tires balanced. That's all the pertinent information I can really think of right now. Any help?
  2. ace940

    ace940 Member

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    ur prolly just hearing the gears in the rear meshing. i wouldnt worry about it unless it is really bad
  3. revhead347

    revhead347 I have face herpes.

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    Sometimes when the bearings on the leigh shaft get a little worn it causes a funny noise like that from the transmission. I get it real bad in 4th gear at mid or above throttle at low speeds. I've talked to Tremec and Hanlon about it many times, and they both say it's just the way it is. It's more prevelant on the 3550 series transmission. Not sure if that's what your experiencing; I'm just relaying my experience.

    Kurt
  4. 02 281 GT

    02 281 GT Active Member

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    What I'm experiencing is more of a grinding noise at very low speeds (like when coming to a stop or rolling slowly in traffic) that occurs regardless of whether the transmission is in or out of gear.
  5. ace940

    ace940 Member

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    if u coast in first at idle on flat ground and the car does the thing like its on and off the gas, does the grinding come and go as ur rocking back and forth? cuz my car does that in reverse. and i can always hear my gears in the tranny. last time i changed my fluid there were no flakes so im assuming its fine.
  6. 02 281 GT

    02 281 GT Active Member

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    I'm not sure what you mean by rocking back and forth. I changed the fluid in my tranny about nine months ago and it looked fine. It really doesn't feel or sound like it's coming from the tranny anyway. It's definitely coming from the rear diff/axle.
  7. 02 281 GT

    02 281 GT Active Member

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    Thought I'd revive this thread as I found time to replace my axle bearings and seals yesterday. The grinding noise is still there, but to a lesser extent. However, I did notice that there are quite a few scratches (gouges, really) in the diff cover that run the entire length of it—from top to bottom—that were obviously caused by impact from the ring gear. There was also a pile of metal shavings on the fill plug that was more than half an inch tall. Could I be looking at a meshing problem with the gears?
  8. revhead347

    revhead347 I have face herpes.

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    Whatever it is, it's messed up and there is a good chance it's about to explode or seize up. You are past the point of speculating. Time to pull the cover and take a look.

    Kurt
  9. 02 281 GT

    02 281 GT Active Member

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    I had the cover off when I was replacing the axle bearings. I'm not really too familiar with the rear diff and gears to really tell if anything is wrong. The gears themselves didn't look like they were heavily damaged or anything like that. I couldn't tell whether the metal shavings were from the diff itself or diff cover. The spider gears didn't look particularly damaged or stressed either.
  10. revhead347

    revhead347 I have face herpes.

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    They have to be coming from somwhere. Any possibility the inner bearings are messed up? That could cause the carrier to move. It still shouldn't move enough to hit the cover.

    Kurt
  11. 02 281 GT

    02 281 GT Active Member

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    I didn't get a good look at the inner bearings when I had the cover off, unfortunately. I can't think of any reason why the bearings would be damaged unless it was filled with the wrong fluid when the gears were done or if they simply reused the original bearings and they're just showing their age.
  12. revhead347

    revhead347 I have face herpes.

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    If the gears and the spiders look good, that's a good thing, because pretty much anything else doesn't require special tools to do. I would pull the cover, and rotate everything and look at it carefully to make sure it's good. You won't be able to see the inner bearings without pulling the caps. Hopefully it's just a main bearing gone bad, because that's not a hard thing to change. Just make sure you put all the shims back in the same place and you don't have to realign the gears.

    Kurt
  13. 02 281 GT

    02 281 GT Active Member

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    Thanks for your help. I'll be sure to take a look at it as soon as I get a chance. I hope it's just a bearing. The rear end really isn't the next place where I wanted to be dumping a lot of money. I'm not making near enough power to justify a built rear end. And of course I would just have to upgrade if I did need to get in there and replace major components. :rolleyes:
  14. revhead347

    revhead347 I have face herpes.

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    I don't think the bearings are that expensive. It is a hassle to change them though. You have to get that little bastard 7/16" bolt out of the center to get the C clips out, take all the brakes apart again, and the slide the axles out to pull the carrier. Oh, and while you are in there, unbolt your driveshaft and check for too much play in the pinion bearings.

    Kurt
  15. 02 281 GT

    02 281 GT Active Member

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    I pretty much went through all that to change the axle bearings. I always use an 8mm short socket with about a 10" extension. That makes it pretty easy to get out of there. Are the carrier bearings pressed onto the carrier?
  16. revhead347

    revhead347 I have face herpes.

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    Yeah, they are pressed on, but they usually aren't hard to get off.

    Kurt
  17. 02 281 GT

    02 281 GT Active Member

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    You think it would be too difficult to throw in a t-lok rebuild kit while I have it out? Too diffcult for someone who's never done that before, I mean.
  18. revhead347

    revhead347 I have face herpes.

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    I wouldn't say it's difficult, but it's definately a pain in the butt.

    Kurt
  19. 02 281 GT

    02 281 GT Active Member

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    I found a gear install write-up online where they do a t-lok rebuild along with it. It doesn't look too difficult if you already have the diff out to begin with. The car does have over 105k miles on it. No telling what kind of shape the original clutches are in.
  20. 02 281 GT

    02 281 GT Active Member

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    Would a rear-end girdle be something I could use? I'm perfectly comfortable with using the stock diff cover. The only thing that gives me pause is the gouges in the original. A girdle would be nice, but I'd like to save $185 if I can.

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