Transmission noise (still!) V2

JohninKuranda

JohninKuranda

Senior Member
I have posted several times before about a transmission noise. Over the past few years, I have dropped the rear end several times and removed the transmission. Over several rebuilds, I think the only original part is the transmission case.

Yesterday I removed the rear end from the U-joint and started the engine. The noise was still there - very high in first gear and reverse, less in second gear, but still noticeable in third gear. Today I removed the transmission. With the assistance of a fellow enthusiast with a stethoscope, slow and steady was my mantra. The noise seems to originate from the area near the main drive gear comes into contact with cluster gear. This Youtube video demonstrates the noise - https://youtube.com/shorts/FlLgvjgv7j4 . Under power, I guess that noise just grows to become the whine/chatter etc that is causing the issue.

Looking at both the current (almost new!) cluster gear, and the one very recently replaced, there appear to be scratch marks on one side of the gear on both units. The attachment pic is the current gear. Hopefully the marks can be seen.

If any Fordbarners have some ideas or suggestions about how to rectify this, I would dearly love to hear. I want to enjoy driving my Model A; not be embarassed to do so because of the transmission noise. As a reminder from a previous post, this was the noise that I am trying to get rid of. https://youtube.com/shorts/nYG2MGJvGCU?si=ZxLTylari8Q9f_v_

Many thanks
John
 

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does it still make that horrendous noise when you release the clutch pedal?

if so the first thing i would check is the end play on the crank shaft. (it is only supposed to be a few thousands)
there is very little clearance between the rear main cap where the drain tube exits the cap and the crank shaft. if that crank comes back too far it will hit.

then if that is ok. pull that ****** lots of things to make noise inside there. brearings, gear mesh, shafts worn out.

it has to come out anyway

OU
 
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John, you refer to several rebuilds and the case possibly being the only original part left. This doesn't tell us much without searching back for your old postings. A list of what has actually been done in these rebuilds might help. Parts replaced with "NEW" parts? Parts replaced with "good used" parts? Bearing replacements? Front & rear ball bearings? Internal roller bearings? It's easy to see you're stumped, at this point, and we can all reflect on this frustration, but more background info would be helpful.
 
I realize that you have received many suggestions...my ideas may be nothing new...

In the first video,(https://www.youtube.com/shorts/FlLgvjgv7j4) as you move the main drive gear by hand, there seems to be a lot of movement between it and the main shaft, looking where the main shaft fits into the main drive gear shaft. This is where a needle bearing is, Les Andrews calls it the main drive gear pilot bearing(shown on page 1-340 in the red book)......not to be confused to the pilot bearing in the flywheel.

If and when you disassemble the transmission I would sure check those surfaces and clearances where the needle bearings ride.

The noise is amazingly consistent.

I do not believe it is the flywheel pilot bearing as that only turns when the clutch pedal is fully depressed with the engine running and the transmission is in gear.

You would expect some obvious wear marks, or bits of metal in the oil.

Below is a picture of the bearing that I am referring to....One of the two bearings shown is worn and the rollers are not parallel...
 

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bobbader said:
John, you refer to several rebuilds and the case possibly being the only original part left. This doesn't tell us much without searching back for your old postings. A list of what has actually been done in these rebuilds might help. Parts replaced with "NEW" parts? Parts replaced with "good used" parts? Bearing replacements? Front & rear ball bearings? Internal roller bearings? It's easy to see you're stumped, at this point, and we can all reflect on this frustration, but more background info would be helpful.
Click to expand...

Yes, all parts have been replaced with NEW parts - some direct from Snyders, others from a dealer here in Asutralia who purchases from Snyders. All the gears (cluster, reverse, second & high etc), roller rearings, front and rear ball bearing, pilot bearing. Throwout bearing, throwout bearing hub. Main Shaft. Retaining rings. Literally all parts - save for the case and the spacers in the the cluster gear.
 
1955cj5 said:
I realize that you have received many suggestions...my ideas may be nothing new...

In the first video,(https://www.youtube.com/shorts/FlLgvjgv7j4) as you move the main drive gear by hand, there seems to be a lot of movement between it and the main shaft, looking where the main shaft fits into the main drive gear shaft. This is where a needle bearing is, Les Andrews calls it the main drive gear pilot bearing(shown on page 1-340 in the red book)......not to be confused to the pilot bearing in the flywheel.

If and when you disassemble the transmission I would sure check those surfaces and clearances where the needle bearings ride.

The noise is amazingly consistent.

I do not believe it is the flywheel pilot bearing as that only turns when the clutch pedal is fully depressed with the engine running and the transmission is in gear.

You would expect some obvious wear marks, or bits of metal in the oil.

Below is a picture of the bearing that I am referring to....One of the two bearings shown is worn and the rollers are not parallel...
Click to expand...


Fading light ended my dismantling yesterday - I now have just the transmission case and the gears on a bench and I will continue the tear down later this morning. Many thanks
 
Just a couple photos to compare. This is the location of the bearing I was wondering about...
 

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There have been problems with the new replacements for the small inside main & countersfaft roller bearings that were originally made by Hyatt. Nobody makes those as good as Hyatt did. The other thing to check is the clutch housing alignment. If it's too far off, it puts a hell of a strain on the input shaft bearing and the main shaft stabilizer roller bearing.
 
John, thanks from r the info on the rebuilding process. Reading what you’ve done, I too would side with Rotorwrench on areas other than the transmission itself.
 
Well, how about this theory from left field?

The transmission is now on my work bench. As I partially removed the shaft that connects to the U-joint, the chatter remained. Removed it completely, the chatter remained. So that vindicates the theory that the cause is at the front of the transmission case as was suggested by the mechanical stethoscope. The only items remaining are the cluster gear and the drive shaft. The cluster gear fits very snuggly in the transmission case on its shaft. Basically fixed. So that leaves the drive shaft. The variable here is, as I see it, the ball bearing. And here is my left field thought. The drive shaft is pressed into the ball bearing and then the ball bearing is seated in the transmission case. So two areas that could cause the gear on the end of the drive shaft to be in a position to incorrectly engage the cluster gear. The ball bearing perhaps not seated far enough on the drive shaft, or indeed seated too far. And in turn the seating of the ball bearing in the transmission case. Or perhaps whilst the overall circumference of the bearing and the centre hole circumference were correct, the thickness of the ball bearing itself was either too large, or indeed too small.

Happy for anyone to rip this theory to shreds, but I just cannot see any other circumstances that would cause the noise. But I will certainly also look at the suggestion regarding the clutch.

All the gears have been cleaned, inspected and wrapped in paper. I will be ordering all new bearings, gaskets etc. paying particular attention to the front ball bearing! None of the roller bearings appeared to be out of kilter in any way.

John
 
Your YouTube video shows an inordinate amount of noise (and clearance) between the main drive and cluster gears. The amount of noise is on full display when rotating the main drive gear input shaft so it isn't just due to one or a few teeth. Something is definitely off here! Is the main drive gear new or used?
 
now that you have that ****** out.
start and run that engine.
that will eliminate any chance the noise is from the engine. then go back to the ******.

OU
 
ursus said:
Your YouTube video shows an inordinate amount of noise (and clearance) between the main drive and cluster gears. The amount of noise is on full display when rotating the main drive gear input shaft so it isn't just due to one or a few teeth. Something is definitely off here! Is the main drive gear new or used?
Click to expand...

It was replaced as New
 
I am in favor of Old Ugly's suggestion of running the engine with the transmission out of the car. I also would advise running the transmission out of the car. You can do this with a large drill motor that will clamp on the input shaft. Some of the right angle drill motors have a large chuck. If the trans still wines then I would investigate what you posted in Post # 13. If no noise in the engine or trans then I would check the alignment between the trans and the engine. Always good to test one thing at a time.

In the past, when I wanted to run something with a large shaft from a drill motor with a chuck that was too small, I made a adapter.
 
Are you using the sealed one side main drive gear bearing ? Are you then thinking that you don’t need the main drive gear baffle ? If this baffle is not used it would allow the bearing and drive gear to move back about .020 ( the thickness of the baffle ) if the baffle is installed backwards it will lock the transmission ( don’t ask how I know ) I may have thought that I didn’t need the baffle because of the sealed one side main bearing !? And then found out the main drive gear interfered with the cluster gear , in my defense this was 25 years ago . If you were closer I would let you try my since removed transmission replaced by a Mitchell synchronized transmission .
 
nkaminar has suggested running that ****** with a drill.

when running the ****** while it is out of the car. find a piece of heater hose that will hose clamp onto the input shaft then step it down for the drill. pretty simple.

OU
 
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