Noisy five speed part 2

[steve]

Since the subject is being discussed. I have been thru a several tranmission changes over the past few years. 3 of them regular 265 5 speeds and 1 close ratio dogleg.

All of the OD swaps were attemps to get rid of the annoying rattling at idle. Is it just the boxes I managed to get all make noise? The close ratio was the only one that was silent and smooth.

The noise is so bad I'd rather keep my foot on the clutch at a stop light. Ive tried raising and lower the idle without much relief.

I do not have a stock engine but it idles smooth. As much as I didnt like the shift pattern on the close ratio I am considering going back to get rid of the noise.

Any suggestions?

 

[jhjacobs]

I've had input shaft bearing failures (noisy) on my Bavaria and now my Coupe. It rattles at idle when the clutch is engaged (in neutral) and it makes noise all the time when running. I too keep my foot on the clutch often when not moving. It only takes a small pit int he bearing to be really annoying. I've come to believe that the input shaft bearing is prone to failure because it takes all the vibration from the engine. So, to your point, you may have had two transmissions with worn input shaft bearings. I'm planning to dig into mine this fall.

I've also had a worn intermiddiant shaft bearing. These will whine all the time and worse under load. However, I don't think this matches your description. If this bearing is bad you can feel the noise when driving if you feel just behind the parking brake.

 

[steve]

Well the last one I put in was a rebuilt unit. So I would assume that the bearing would be new. I dont really notice any noise while driving and it shifts smooth. Its just at idle with the clutch out. It sounds like crap!

The engine sounds so nice that it really sucks have to listen to rack rack rack rack!

 

[shanon]

...so did you lay a patch all the way home steve?

8)
-shanon

 

[dave v. in nc]

noise...

I wasn't aware until now that I was previously married to a 5-speed with pitted bearings..."whines all the time, especially under load"....Things are much better now. All transmissions, synchros, and such seem to be much better on the current model. Or maybe its the way that I take care of the machinery now...Nonetheless, its all better....Dave V. in NC

 

[jhjacobs]

Its just at idle with the clutch out. It sounds like crap!

When you say the clutch is out you mean it is in neutral and the pedal is not pushed? If this is the case, the only things spinning after the engine is the pressure plate, and clutch (which won't make noise unless the clutch or pressure plate springs are loose / broken) and the input shaft bearing. Under load, a bad input shaft bearing noise will usually be downed out by other noises and the pressures on it are different. In both of my cases the racket was (and is) pretty loud when in neutral with the clutch out but in the first case the pit in the bearing was tiny and barely noticeable with spinning in on my fingers. I'm still working up the inspiration to pull the tranny on my coupe in the second case.

If you mean the clutch pedal is depressed and the transmission is in gear the things spinning are the throwout bearing (which you can usually feel vibration in the pedal if bad) and the pilot bearing. I am not very familiar with noises from a bad pilot bearing but I would assume it could scream and it might cause clutch chatter with engaging.

If memory serves (bad assumption in my case), the transmission has a couple of alignment pins (which bolts pass through similar to the head alignment pins) to ensure it is properly centered when connecting it to the engine. I suppose that if the transmission was not lined up 100% you could get all kinds of crazy sounds.

 

[steve]

Yes that is exactly it! When the clutch is out in neutral and warm it rattles away. Cold it is still there but not nearly as bad. When I push in the clutch the noise goes away. Let it out and it comes back.

Dont really hear it when driving because everything drowns it out but I'm sure it's still there.

Its just at idle with the clutch out. It sounds like crap!

When you say the clutch is out you mean it is in neutral and the pedal is not pushed? If this is the case, the only things spinning after the engine is the pressure plate, and clutch (which won't make noise unless the clutch or pressure plate springs are loose / broken) and the input shaft bearing. Under load, a bad input shaft bearing noise will usually be downed out by other noises and the pressures on it are different. In both of my cases the racket was (and is) pretty loud when in neutral with the clutch out but in the first case the pit in the bearing was tiny and barely noticeable with spinning in on my fingers. I'm still working up the inspiration to pull the tranny on my coupe in the second case.

If you mean the clutch pedal is depressed and the transmission is in gear the things spinning are the throwout bearing (which you can usually feel vibration in the pedal if bad) and the pilot bearing. I am not very familiar with noises from a bad pilot bearing but I would assume it could scream and it might cause clutch chatter with engaging.

If memory serves (bad assumption in my case), the transmission has a couple of alignment pins (which bolts pass through similar to the head alignment pins) to ensure it is properly centered when connecting it to the engine. I suppose that if the transmission was not lined up 100% you could get all kinds of crazy sounds.

 

[steve]

...so did you lay a patch all the way home steve?

8)
-shanon

I did! Sure was fun to be behind the wheel of my coupe again.