Knocking/vibration through shifter (lots of details)

Discussion in 'Fox 5.0 Mustang Tech' started by boostfrk, Apr 2, 2012.


  1. louieb

    louieb Member

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    interesting, i have similar problem. I have a centerforce clutch. that does rattle. I looked under car ,and the front of the trans were it connects to the motor has oil all over it. the trans was just checked, and its full. makes me think its comming from rear main seal or somthing. I also have a strange sound sounds similar to rocker arm being loose. Also when i push in clutch somtimes i hear a clunk sound, like metel hitting metel. and other times it has no clunk sound. could that mean i have the crank endplay loosening up? DSS payed no mind to tollarenses with my motor. 19 mm of end play, just under specs. when motor was freshly installed. i called them out on it, and they said well its still within specs.
     
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  2. boostfrk

    boostfrk Active Member

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    Update, kind of, I guess.

    A couple months back I replaced the clutch, throwout out bearing, flywheel, rear main seal, clutch fork and clutch cable. So everything in front of the transmission, gear drive wise, is new. I also have a different rear axle assembly installed and an aluminum driveshaft installed. So everything behind the transmission, while not new, is different than previously.

    The rattling/vibration is still there.

    To me, that singles out the fact that it's the transmission. Whether or not it's a problem or not, I don't know. The vibration and rattling goes away after driving for 20-30 minutes. So when the gear oil is nice and hot and the mechanicals inside the transmission have heated up and are somewhat larger, I suppose, due to the heat.

    I don't really think there's anything else to chase down at this point. I'm not interested in buying and swapping out a new transmission so I suppose I'm just stuck with it.
     
    #22
  3. 7991LXnSHO

    7991LXnSHO Well-Known Member

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    The shop made up a tool to pull mine when they replaced the rear seal and drive shaft, and I could not be happier without the vibration. I also went with a poly tranny mount at that time. The seal was not leaking yet, but shook badly over a certain speed. It was scoring both parts. And it Should be easy to check if that is loose when cool.

    A deer slug into the oil pan at 5000 RPM may also be effective, as well as maybe using a big cliff.
     
    #23
  4. lizardsman

    lizardsman Member

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    As stupid as this sounds, instead of just throwing parts at it when you don't even know where the sound is coming from, go to the parts store, get a small funnel, 10 feet of 3/4 hose and a **** load of zip ties. Put the funnel on the hose, put that where you think the noise is coming from, zip tie the hose out of the way all the way to the inside of the car, usually threw the window. Now drive the car, do what you need to make it make the noise and put the hose to your ear. Just keep moving the hose until you hear it the loudest threw the hose. Cheap, easy, reusuable and it works. You might only hear it threw the hose when it's right next to the culprit. just remember to put an earplug in the other ear. Let me know if this helps everyone out.
     
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  5. Illuminator

    Illuminator Active Member

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    So any progress with the vibration? I have almost identical issue with mine that seems to be inconsistent at best. Usually comes on around 3k under hard acceleration, and decel for that matter. Bad oscillations through the shifter to the point of knob coming loose. I notice it tapers off as lightening up on the pedal and r's seem to, but at highway speeds and having 4.10's the r's are there anyhow, and the vibration seems to gyrate so bad the mirrors are shaking. Get out of the car after 20mi trip and your body is still shaking. All this and yet no leaks from trans rear seal. Really strange. I thought for sure would be the u-joints, but not sure how the driveshaft could vibrate this bad and not blow the seal out. Any suggestions?
     
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  6. boostfrk

    boostfrk Active Member

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    No progress based on my response in post #22 just a few posts up the page. Yours sounds worse than mine. Yours sounds more like a harmonic frequency imbalance that's occurring at ~3k RPM's. Have you checked the u-joints or replaced them? It's a cheap $20 and if they haven't been replaced in awhile it wouldn't hurt.
     
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  7. Illuminator

    Illuminator Active Member

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    Doing so today in fact....a friend mentioned another idea which had crossed my mind. Input shaft and/or bearing....hmm
     
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  8. lizardsman

    lizardsman Member

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    I had a bad input shaft on mine. I could only hear a rythmitic sound cruising in fifth at 2500. Pipes make it hard to hear in lower gears. It eliminated all my vibration and noise while going interstate and above speeds. I had no luck finding just the race and bearing and the 15 needle bearings so I called my buddy at the tranny shop and he gave me his supplier. $35 with next day and pretty easy install. You might need more shims to eliminate play, I got lucky. Good time to install steel bearing retainer if you haven't already.
     
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  9. Illuminator

    Illuminator Active Member

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    Yeah theres a consistent vibe at cruising speeds that has an occillating effect....I'm going to bet the U-joints won't do anything, if I can ever get them off that is....lol damn bolts are a bear
     
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  10. lizardsman

    lizardsman Member

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    Yes the 4 12mm 12 point bolts are not fun. I bought a cheap straight 12mm 12 point wrench and cut the open end off and used a long pipe. Heat will help, but be carefull of the pinion seal. And I would recommend replacing them, hade them fall out once. They come with locktite on them. If it is the front shaft you wanna take care of it quick. Tranny guy said as the shaft wobbles on the main shaft it creates a burr on the end of the shaft and after it creates the bur or lip the main shaft is toast. That's why I wish I could afford a tko 600.
     
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  11. Illuminator

    Illuminator Active Member

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    I changed em...didn't like the looks of the rear brakes so dropped rotors to be turned and ordered new calipers why I was at it. They sent one caliper with missing hardware so still waiting. I did the running on jack stand test and heard some weird sounds I've never heard before in the trans area in 3rd thru 5th gear....a knocking noise almost like a clunk in 5th....under accel that is...hmmm Wish I had my tax return, would probably just order a T56 Magnum.....lol
     
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  12. lizardsman

    lizardsman Member

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    When you put the car on jack stands you can hear a lot of stuff that you normally wouldn't hear due to the fact that there's no load on any of the drivetrain. Correct me if I'm wrong as I've believed this for a long time. But t56, at the nmra spring break shootout tremec was there of course, and that is a smooth shifting tranny even with the stock shifter. Think you would really enjoy it!
     
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  13. Illuminator

    Illuminator Active Member

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    Well, going to have to wait on the T56 as the U-Joints did the trick...just took a trip to store with a few 5k+ shifts with no noticeable vibe all the way up over 100 mph.....got 4.10's so not too much more after that with the 245's that need replacing. I'm guestimating speed because the new speedo cable I put on a few months ago has already cooked on the headers and burnt thru again, got another cable just dread doing that job about as much as dropping the trans...last time I did it my hands were cut up pretty bad from fishing under the dash and all the sharp crap the factory left over, and back was tossed out for a few weeks after getting wedged between seat and door jam upside down....almost had to yell for a rescue I had been down there so long....lol

    Update!!
    OK...sidenote, the vibe did not completely go away, it is still there after say 75mph and up...progressively getting worse with speed.... I am certain its the rear rotors, which PO hacked to 5-lug from 4....just ordered new rotors and will see if that cures it.

    Do you have rear disk brake conv by chance? I just isolated my vibe to the rotors after replacing most everything short of yanking trans.... still have some loose/funny noises in 5th, probably the T5 on the way out.... Saving for a Magnum T56, so hopefully the T5 holds out a little longer....
     
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  14. Taino

    Taino Member

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    Kinda solved my shifter vibration issue, The manual clutch cable adjuster had loosend up. My mechanic noticed it while changing the oil, I had mentioned the clutch didnt feel right. He tightened it up juuuust enough to keep the quadrant from vibrating and agjusted the clutch cable so it engaged nicely. When I drove home it helped it quite a bit. Just throwing it out there see if this helps someone
     
    #34

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