TKO Neutral Squeal

[PaulProe]

I recently put my TKO600 thru some paces as I drove the backroads of Colorado. Spent a fair amount of time in 3rd and 4th, but really not enough to overheat the transmission. Track days would be harder on it and didn't notice any issues then.

After driving about 50 miles going up and down in 3rd/4th, I started to notice a distinct squeal when the transmission went into neutral. Slight squeal as I passed neutral and very loud if I put it in neutral. Shifted fine and no noise while in gear. Later in the day, after a few miles in 5th, the squeal went away.

Clutch in, the squeal goes away. Clutch out and in neutral or shifting as you pass thru neutral is the only time you hear it.

Next day, a little heat into the tranny and the squeal is back. Same thing, no issues in gear, only squeal in neutral or as you passed thru neutral Seems to come and go.

I've googled the innerwebs and nothing to be found. I know what bad bearings sound like and I remember the good ole days when the Chevy synchronizers would act up. But nothing like this.

Anyone have any ideas on what to look for? Hate to tear it apart for an 'exploratory' unless I have an idea of what I'm looking for.

Thanks

Paul

[LG57]

Sounds like you TOB is starting to go away.

[Gaz64]

Paul,

While this very loud noise in neutral is there, can you depress the clutch pedal a small amount, and see if the noise changes?

Gary

[PaulProe]

Originally Posted by Gaz64

Paul,

While this very loud noise in neutral is there, can you depress the clutch pedal a small amount, and see if the noise changes?

Gary

Gary
As soon as the clutch begins to move, the squeal quits.

If it were a throw-out bearing, would it not also squeal when released and in a given gear? This only does it in neutral or as the shift pattern moves thru neutral.

Paul

[Gaz64]

Can you post a link to a video please Paul?

While the noise is there, does it go away if you just lean on the shifter a fraction?

In neutral, all gears on the mainshaft are rolling over at their respective speeds.

If this was a particular gear needle bearing or thrust race, the noise would be there in every gear, except the gear causing the noise.

Gary

[PaulProe]

Gary
Don't have a video of when it was occuring on our cruise, and it will be a couple weeks before I am able to take it out again.

The pitch of the squeal did seem to change as I moved the shift lever, making me think it was a synchronizer ring or face. As soon as any selected gear was engaged/clutch in, the noise stopped. For that matter, as soon as the clutch was pushed in, the noise stopped. Same for all five gears and reverse. The only time the noise appeared is if all are running free.

My thoughts were the lubrication fluid may have foamed as when the temperature lowered, it did seem to better itself to disappearing completely. Yet the next day when the heat went up again, it re-appeared.

[Gaz64]

Paul,

What fluid are you using, and is the level correct?

A google search for TKO600 squeal:

https://www.google.com/search?q=tko6...hrome&ie=UTF-8

Gary

[wolf k]

Clutch out, trans in neutral, does the squeal change in intensity as you raise the revs ?

[PaulProe]

Finally figured it out - troubleshooting can be very confusing.

Turns out the noise was the nose of the starter gear rubbing on the spinning flywheel because the ignition switch wasn't snapping back from the start position when released.

The confusion of why it was doing it only when you went thru neutral - the car has a neutral safety switch/relay and in neutral, it would energize the start circuit and the motor would spin, when you left neutral, the circuit would break and the motor snap back to the park position. With the ignition switch hanging up, it would supply power to the neutral safety circuit full time, allowing it to do its thing.

Cheap import switches Big shout-out to PowerMaster starters being able to stand up to this punishment.

Now to find a switch that will hold up. 2nd one to go bad in 5 years. Hope this helps someone else.

Anyone have a suggestion on a quality ignition switch? Car is 'period correct' so it needs to look like the Lucas style on the outside dash side. I've tried the cheap chinese imports and Dorman (which is also an import and the one that has failed twice) Considering Cole-Hersee now, but it is probably an import also

? ? ?

Thanks for the group support.

Paul

[Gaz64]

I would be pulling the starter to see what damage has occurred to the faces of the pinion and ring gear.
Any car I know of that the pinion is thrown into a spinning ring gear causes the awful grinding noise we have all heard before.

Gary

[lnfletcher]

Thanks for letting us know what you found! That's a strange one that I'll try to file in the recesses somewhere in my brain. Most likely never see it again, but who knows!

[MaSnaka]

The good news...You are not pulling your trans, rebuilding it and still hearing a squeal when you put it all back together. Good job on the diagnosis.

John

[Gaz64]

Paul,

What you also need to do is involve the alternator in the start relay circuit.

That way the starter motor can only operate in neutral under 400 rpm or so.

I made my own remote start in the mid 90s that used this principle.

Gary