trans noise at idle, goes away when I clutch in

trans noise at idle, goes away when I clutch in. humming noise, sounds like a fan, goes away when I step on the clutch. from what I understand, the throw out bearing does not ride on the pressure plate constantly and only engages when you clutch in. Based on this, the throw out is not the problem. My guess is the input shaft bearing. unless my pedal adjustment is set too forward and thus applying enough pressure to engage even when the pedal is not pressed.

 

Got some info here that may help and I do agree with your thoughts that the pilot bearing is the issue .
What year is your truck ?
What size motor ?
http://www.tacomaworld.com/forum/te...ation-your-5-speed-transmission-write-up.html

 

its a w59 on my 3rz. clutch is new with about 10k so far. from what you said in your link my clutch is just breaking in. ill adjust the pedal and check back.

 

most cases that noise is from your pilot or throwout bearing, it free spins when the clutch is in so if its worn you get a rumbling noise from it.

it is held tight when it is engaged so that's why you only hear it with the clutch in.

to replace it you have to pull the tranny

 

so i adjusted the pedal so I have a few mm of slack. The noise level dropped in half but is still there. Here is my thoughts on why its the input shaft bearing and not the throwout or pilot.

Is the pilot bearing in constant contact with the end of the input shaft on engine side? If so then i dont think this is my issue because stepping in the clutch wont change anything

The throwout only makes contact when clutching in so this cant be making noise on its own when not on the clutch.

Input shaft bearing. Now some may confuse this with the pilot. Pilot is on the engine side and there is another bearing on the trans side. Anyone with experience with this part?

At idle, in neutral there is noise. Pressure plate is clamping the disc and spinning the input shaft. Stepping on the clutch adds the throwout in and removes the input shaft from the equation. I also notice a whine from my trans at low speeds in first. Am I on the mony here when I say input shaft bearing?

 

pilot bearing fits into the crankshaft . When the clutch pedal is pushed down to the floor , the radial load of the clutch disc is supported by the pilot bearing . Pilot bearing noise usually goes away by gently feathering the clutch pedal allowing the pressure plate to clamp the clutch disc .Thats about the easiest way to diagnose a bad pilot .

When you push the clutch pedal down to the floor , all the gearing inside the transmission slowly comes to a stop . When you remove your foot from the clutch in nuetral , all the gearing has to start turning again .

Is there enough fluid in the transmission ?
Do you hear any noise in 4th gear ?
The reason i ask about direct drive or 4th gear ?
When you are in direct drive , there is no load on the countershaft .These transmissions are known to have countershaft bearing problems.
when the transmission is in 1st , 2nd , or 3rd gear , there is load on the countershaft bearings . You should be able to hear the same noise shifting up through the gears .If the noise goes away when you are in 4th , you have noisy countershaft bearings . If the noise continues in 4th and 5th the input bearing and possibly output bearing on the mainshaft are noisy

 

Don't the other gears (not 4th) also side-load the bearings on the input and output shafts?

Does the countershaft spin when in neutral? (assuming vehicle is sitting still)

If the countershaft bearings are bad, will there not also be a noise in 5th gear?

I'm curious about how all of this works since I currently have one bad W59 transmission on the bench, and another in my truck.

 

The noise definetely comes when I release my foot from the clutch in neutral, in gear, at a stop and in motion. I dont notice it in 4th or 5th but that may be from my tires and exhaust. The problem is definitely on the transmission side of the input shaft. I have a 80 mile drive tonight so Ill get a better answer on 4th and 5th. Also Ill be changing the trans and transfer case fluid when I arrive so Ill check back in

 

Not trying to hijack the thread, but I seem to have the same symptoms. For me it is happening in neutral, 1st, 2nd, and 3rd, not 4th and 5th.

Given that it is probably the counter shaft bearings, how long can I go before I must replace those or just do a rebuild?

 

You have to crack the whole transmission open and pull it completely apart to replace the counter shaft bearings, so best to replace all bearings, seals, and synchros while you're in there. Yes, it's a rebuild. The parts are about $300, but the labor is huge unless you do most of it yourself. It's not significantly more labor to do the full rebuild, so you might as well. A lot of people just buy a used transmission. I did that and got burned - now I have two trannys with bad bearings that need to be rebuilt.

 

Great pic of the W59 . Does that critter still use Toyo-Koygo bearings?
I must have built well over a thousand of those w59,s . Horrible OEM bearings but very simple to change them out .

Yes . the countershaft spins in N . If you look at the input shaft or 4th gear at very front , its in direct contact with the 4th gear on the countershaft . As soon as you remove your foot from the clutch , the whole assembly begins turning . With this said , its the synchronizers that control the powerflow . The picture above shows the transmission is presently in Neutral.

All helical cut gearing creates a thrust load .In the picture above , all gears are helical except the spur cut gearing for reverse.

Yes there will be noise if the bearings on the countershaft are bad in 5th gear , but easier to diagnose countershaft bearings from 1st gear to 3rd gear while test driving .

 

I'm not sure what kind of bearings they are. It came from a 1996 2.7L Tacoma 4x4. It will have all new bearings soon - I ordered a kit from a link you suggested to me in another thread. I've taken the shift forks off, and it's now at a shop to have the pulling and pressing done. I looked at the price of the tools I would need—a nice puller, a press, and a very strong pair of snap ring pliers—and realized it would be cheaper to have someone else do that part.

The particular transmission in the picture had a loud clacking noise (I think a really busted bearing) at idle and in all gears except 4th. From what you're saying, I guess it's probably a busted countershaft bearing. The input shaft bearing feels like there's no problem when you spin it by hand.

The other w59 that's currently in my truck has a loud bearing whine at idle and in all gears except 4th. It also has serious problems shifting into 4th, so I suspect that synchro is either worn out or possibly cracked. I might also have this one rebuilt for sale once the other is ready and back in the truck.

Thanks for the great info—it's cool learning about how all of this works!

 

I changed the trans and tcase oil over the weekend and found out I was pretty much dry. The tranny had about half qt of black. tcase had about the same of dark brown.

 

Yikes .....Thats not a good sign . All those miles without the proper oil level will kill your trans mighty early . Any better now that the fluid is at the proper level ?

 

Yes it spins. All of the gears spin free on the main shaft until they are selected. Counter shaft bearings seldom go bad main shaft bearings yes. Bad head gear bearing will make noise in every gear except direct.

 

Dry gears on the main shaft will make all kinds of noise some times if you catch it soon enough once they get re oiled they maybe fine but low oil can also trash them overtime.

 

So which bearing is the head gear bearing?

 

12k miles in my ownership. The whine is still there but definetely less noticable.

The trans started making noise after I was rev bashing it quite a bit at pismo dunes. I put on 9k miles prior to this without problem or any symptoms. It's always felt good mechanically but the whine is still there. I also see the oil's exit point. Leaks where the trans and tcase meet. Ill monitor it for now, see what happens, hopefully the fresh oil does something. On a side note my truck just hit 200000.

 

The input shaft. All manual transmissions will make some noise in neutral there is a lot of stuff turning in there in neutral. The head gear turns the counter shaft turns and so do all the gears on the main shaft. The question is how much is too much noise? Mine from day one has made a slight whine in neutral that is normal if you can find some one that knows about manual transmissions maybe they can have a listen. A head shaft bearing will make a lot of noise it turns the same speed as the engine. The least amount of stress on the bearing will be in direct drive (1 to 1) at that point the input shaft is directly coupled to the main shaft.

 

I started a new thread but now answers. I'm looking for a replacement transmission and I found a 2wd trans from a manual 2rz. I'm sure it will bolt up but can it mate with my existing transfer case?