transmission noise while in neutral, goes away when clutch is depressed.
 

Newbie here, (transmission noise issue,) finishing up on assembling a Frankenstein 1928 pickup. . long story short, no noise when I first heard this truck run. I have since drained and refilled with the correct 600w lube, added a new speedometer cable. I pulled the bell housing inspection plate and the throw out bearing is not making contact with the pressure plate when running in neutral. the previous owner installed a transmission that he freshened with new bearings. I assume the speedo cable has nothing to do with this as it makes noise sitting still. I'll probably pull the transmission top cover tomorrow and do a visual while in the truck. Ideas?

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

Hard to say what makes the noise for sure with out disassembling it, but it probable is a rough bearing new or used.

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

Ross, does it make more noise with the clutch pushed in or out?

It is definitely not the speedo cable.

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

Sounds like potentially he used the poorly manufactured bearings when he freshened with new bearings. Of course he didn't know that they would fail in a few hundred miles....and many vendors still sell them. I am rebuilding a transmission and bought some used bearings from Bert's. The bearings I am talking about are the small roller bearings (two short and one long) as used in the cluster gear and input shaft. This is speculation on my part. My transmission is doing the very same thing. They should be replaced. MAC's sells the correct longer roller bearing, by the way. Do a search on transmission bearings and Tom Endy.

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

Sound to me like the throwout bearing has not been greased or is bad.

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

Quiet with the clutch depressed, sort of a rattle or rub in neutral with the clutch released

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

Could be that when you drained the old oil out that there was STP or something similar which being thick, masked the noise that you now hear. Probably a good thing that you drained it if the bearings are not good as pieces of material will eventually screw up the gear teeth if that is what is going on.

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

My clutch is never depressed. I keep it happy by not riding it when stopped at red lights. LOL
If the throw out bearing isn't touching the clutch fingers, then it should be not moving, so it can't make noise. The pilot bearing is moving with the clutch depressed, and it's stopped when the clutch pedal is released, so that shouldn't be the noise maker either. Wonder if the pressure plate has loose parts?

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

^^^ I'm with Al ^^^

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

There is a grease fitting under that inspection plate. Worth a shot of grease... Chap

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

Ross ,
Is it a whirring orcaligjt whine ? Clutch out and in neautral the main drive gear and cluster are turning. Do not run with trans top off or you will sling oil everywhere ! Just a warning .
The noise occurs usually because of work parts either the pocket bearing in the input shaft or the cluster gear shaft and bearings. I doubt it’s the main bearings but if you get into the trans I would replace them as well. Also, flywheel housing misalignment can also cause an issue or a cracked housing.

It is important when inspecting parts that you make sure main shaft pilot end and input shaft pocket are not gauled or scored inside. Also cluster gearxahaft and bearing condition.
Nothing wrong with taking a look with trans top off as it will give you a heads up on gear condition but I’m not sure it’s going to uncover your issue unless theres a severe bearing failure at the main shaft.
Keep us posted
Larry shepard

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

Check your private messages in the upper right corner of this webpage.
Marshall

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

I just went through this. Make sure the small bearing is in the nose of the input shaft, and if it’s the later transmission, it needs that metal ring spacer. I also had a brand new input shaft bearing that was noisy as well. Exactly the same symptoms you were saying. With the transmission out and the cluster out I could still turn the input shaft and hear the noise and then I can feel it in the bearings. With the clutch in. The throwout bearing is moving, but nothing in the transmission. With the clutch out in neutral the throwout bearing is not moving and the input shaft and cluster gear are moving.

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

I had the same issue on one last summer. Turned out the two front motor mount bolts were loose. Pushing in the clutch stopped the noise. Must have caused the engine to shift just enough to quiet it.
Was a bugger to chase down. Tightened them up and the noise went away.
Worth checking.

Re: transmission noise while in neutral, goes away when clutch is depressed.
 

I doubt that it really ultimately fixed the issue but just temporarily went away. It sounds like your crankshaft end thrust (rear main ) is probably the real issue.
Yes it’s possublt you could have had a pulley rubbing issue but it still can be caused by excessive end thrust crankshaft play .

Larry