Monsterbox

iTrader: (6)

I've posted on this before but now that I've been paying attention to it more I can describe this strange noise a bit better.


1. Engine Running, Clutch Up, Nuetral - (bearing whirling noise, kind of like a race tranny PPG or something)
2. Rev engine, the noise increases with RPM, whirrr, whirrr, its a steady whirr...I can feel a vibration in the shifter with this noise.


At this point most people would think, Input Shaft Bearing is toast....well here's the kicker.

3. Roll car forward 3 inches and sound completely stops, NO NOISE, NO VIRBRATION! Rev engine as much as your want go in and out of gears back to neutral, clutch up/down. NO noise.

and again...

4. Roll forward 3 inches and sound is back. WTF!!!!!



I can roll down the street in nuetral/clutch up and here the noise pass by, whirr...normal...whirr...normal....whirr...and it begins to sound like "card in spokes" as my car's coasting speed increases.


I don't know how worried I should be. Its much more noticeable when the car is cold. After warming up the noise is much quieter. HELP!

Monsterbox

iTrader: (6)

someone please help. I haven't any idea where to start looking. This sounds like driveshaft/diffy issue or something but at the same time the noise is coming from what sounds like in input shaft.

Why would it go away when I push the clutch in if it wasn't the tranny?
Why does the noise come and go depending on the position of the car if it wasn't the rear end related.


My Best Guess:

Something under the car is touching the driveshaft at someplace like the U-Joint. At certain position, the U-Joint is rotated so that its not contacting anything. Then as the car rolls forward a few feet, the U-Joint touches up against the midpipe or something....when clutch is up vibrations from the engine are transmitted through the tranny down to the driveshaft causing that part of the car to rattle.????

papsmagu

iTrader: (19)

check if the drive shaft has play (up and down) at the connection point to the diff. if it does you need to re-torque the driveshaft bolt to the diff because it is comming loose.

NewbernD

iTrader: (1)

Whatever it is it is inside the transmission. When you move the car ahead 3 inches you are changing the orientation of parts inside the tranny. We could speculate all day on what exactly it is but from what you have described it's in the gearbox. My guess would be the inner input shaft bearing.. the one in the tranny that sits between the input and output shaft. When you roll the car forward a few inches it re-orients the shaft so that it doesn't bang around on the bearing that is in the eshaft.

Does it make any noise in 4th gear? Not a definitive test but in 4th, both shafts spin at the same speed and the problem should be minimized.

If you can do this while stationary then it has nothing at all to do with the driveshaft being loose or rubbing on anything. Sorry, just not that simple.

Monsterbox

iTrader: (6)

cannot hear it in any gear except reverse and sometimes in first. When it does make a noise, it sounds like commmon input shaft whining that you here on alot of FD's. However, it just blows my mind that it comes and goes when I move the car.

My 5th gear syncro is a little worn...it still shift in fine but with a slight notch. Maybe its the syncro rattling around?

Should I be pulling the tranny out, etc...what should I do?


The car drives/shifts perfectly fine. Only thing I could complain about is notchy 5th and shifter moves under accel/decel a little.

NewbernD

iTrader: (1)

Rebuild or replace with a good used trans.

Monsterbox

iTrader: (6)

could it be low gear oil or something? I just hate to replace/rebuild when the car drives/shifts perfectly normal. The noise isn't very loud either.

Monsterbox

iTrader: (6)

Looked up Info I had saved from previous Owner

Dealer ship Report - "Rattle noise under veh with AC on but goes away when clutch is pushed"

- Entire tranny rebuilt. New R501 Ball Bearing, R521 Ball Bearing....lots of bearings.

This was in 2003. Only 20k miles max added since then. Why would I be having this issue now again? Low gear oil maybe?

ptrhahn

iTrader: (9)

It's probably still you're main bearing.

Mine would sometimes find a "happy" disposition when I'd come to a stop where it wouldn't be noisy, and then other times it sounded like rocks in the dryer. It drove and shifted fine too. Just a matter of time till it worsens.

MX722

iTrader: (1)

I just experienced this issue a few months ago. My tranny had the same symptoms. Turned out to be a bearing slipping off the input shaft. I would not drive the car anymore and just work on either finding a new transmission, or rebuilding the current one.

fd3rew

iTrader: (1)

Many, many years ago, my car had the same problem but it was immediately after my stupid *** spunned the car hard around a sharp turn doing 80mph. The road was dry and I've brushed up again a concrete barrier. I've messed up a small patch of paint on the plastic bumper cover. It was so small of a spot cosmetically, looking at the car, you probably would think that someone just scraped the bumper leaving a parking spot but that small jolt to the drivetrain was enough to give me a bearing noise in the tranny. I left it alone and it drove fine with the noise for a year or two years or so (DD) until one day the tranny just gave away in rush hour traffic. So, like what the previous poster said, you should get it fix or at least start looking for another gearbox, the car might drive fine but it can also go suddenly. If you wait until it goes completely it won't be a simple rebuild (bearings and syncros) anymore.

Monsterbox

iTrader: (6)

well considering any sort of rebuild would cost alot of money, Ill just drive it till it blows and put in a 300 dollar jspec. I don't see the point in worrying when these tranny's are cheap.

Vibration/Wine isn't bad at all...you don't notice it unless you are listening for it hard.

pomanferrari

iTrader: (1)

This is why they teach you in driving school that if you go into a spin, left foot on the clutch and right foot on the brake. The left foot on the clutch disconnects the rear wheel from the transmission in the event you roll backward which would destroy the transmission.

dgeesaman

iTrader: (7)

If it was rebuilt and the bearing Dave is talking about was replaced, it's likely the input shaft and mainshaft nose had wear also. If you just put another set of bearing rollers in it will wear out very quickly. Rebuilding FD trannys is fine but when the shafts aren't good it becomes expensive fast.

The intermittent sound I would guess is due to heavy wear on one side of one of those shafts at the bearing race. When the bearing rollers are pressing on the rough spot you get noise. 3" at the wheels might correspond to relocating this set of races by 180°. Roll the car forward and the rough spot is no longer there. Just an educated guess. In any case it's inside the gearbox.

It's hard to say how long it will go, but at some point the wear on the bearing will cause it to get loose, misalign, and lock solid. I would start sourcing a good used transmission since this one is not going to keep going forever, and paying someone to rebuild it is usually not a cost effective answer.

Dave

fd3rew

iTrader: (1)

Yeah, it was a damn if you do and damn if you don't situation on one of those 450degrees two lane turns with two apexes. The back came out due to too much engine braking going into the first part and when it broke loose, I had to maintain throttle to finish the second half of the turn. I probably would have clear that wall if the turn was a couple of inches wider but live and learn, as you get older I think back I probably would have clear the wall if I've driven a bit slower too. A used tranny was probably cheaper than hitting the wall with the either the front or side of the car.