Tracking Down a Third Gear Noise! (UPDATE)

[bogdonj]

As some of you may know I've been having a hard time with this noise in the 3rd gear. It's like a growling/rubbing noise and goes away with the clutch pushed in. Sounds like it's coming right under the floor boards. After having one of our friends who specialize in model A's look and listen to it he believe it was a bearing in the transmission. This weekend we pulled the rear end to get at the transmission and so far this is what I have found.

http://youtu.be/A_g7PEnqAbs


The link is a video I took of the U Joint after pulling the outer cover of the torque tube. I notice that the U Joint has a considerable amount of play back and forth... as you can see in the video... is this normal or should it be pretty tight?

I also then looked at the Inner plate that covers the U joint and it looked like it had some noticeable scaring marks in it... Could this be causing my noise? (Pictures below)


I will let you experts decide!




The OTHER THREAD- https://fordbarn.com/forum/showthread.php?t=9939


Justin

[BRENT in 10-uh-C]

It should be tight and there should not be any noticable lash in either direction.

[Kurt in NJ]

The side to side location (the movement you show on you tube) is normal, the bearing in the driveshaft is what locates the rear 1/2 of the u-joint---the side to side movement is needed for alignment because the driveshaft is held rigid by the bearing --if the driveshaft bearing gets loose the u-joint can flop around in the housing.

How much can you move the driveshaft up---down in the torque tube?

How much can you move the u-joint in--out?

How much rotational movement do you have in the in the u-joint (how much turning movement does the front 1/2 need to start moving the rear 1/2)?

With an open "modern type" driveshaft you need to worry about the side play because the u-joint supports the driveshaft and centers it.

[Tom Wesenberg]

And the outer cover should have a nice coating of grease. Was it dry?

Scoring on the inside of the bell means the U-joint was scraping on it at some time.

[bogdonj]

KURT- How much can you move the driveshaft up---down in the torque tube? Haven't looked at this yet!

How much can you move the u-joint in--out? The U JOINT doesn't move in and out..its pretty tight that way.

How much rotational movement do you have in the in the u-joint (how much turning movement does the front 1/2 need to start moving the rear. When moving the U Joint there is very little movement in moving the front 1/2 to start moving the rear!

In theory, if you have marks on the inside of the inner plate wouldn't there be too much movement in the u-joint and that's what is causing it to mark it up?

[bogdonj]

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Originally Posted by Tom Wesenberg

And the outer cover should have a nice coating of grease. Was it dry?

Scoring on the inside of the bell means the U-joint was scraping on it at some time.

yes Tom it was pretty dry... U joint wasn't bad with grease but definitively didn't have the coating you put on your U joints! Will pack it like you do when I reinstall the transmission.

[bogdonj]

Going to pull the tranny this week and see what else I can find that would cause this noise!

[Flathead]

Is the bolt that holds the u-joint to the output shaft tight?

[Gary WA]

Originally Posted by Flathead

Is the bolt that holds the u-joint to the output shaft tight?

And the correct washer in its proper place!!

[columbiA]

If the DS front brg,sleeve or shaft are worn,it could cause the U joint knuckles to rub on the inner cover.Correct oil baffles in the trans?

[bogdonj]

Originally Posted by Gary WA

And the correct washer in its proper place!!

Just checked the attaching bolt and got it to turn a bit but wouldn't say it was loose.....the washer looked to be correct. Should have the transmission out on Friday for a better assessment I did notice he safety wire on the one side bent out and was touching the U joint....just bent it back

[bogdonj]

Finally got the transmission out and took it to our Model A expert and this is what I have found so far. The play in the U Joint is normal and should be present to allow for proper fitment. We did notice that the Main Shaft had play in it and wasn't tight and the noise is coming from the main ball bearing that holds it in. Also discovered that the Pilot bearing had more play in it than it should. So far this is how far we have gotten with the transmission. If he sees anything else we will update it and replace it. All the gears look good and the U joint should defiantly be packed before installing.

Thought I would update this thread so down the line if someone else has a similar issue this will help with them.


Will get it back next week.. paint it and reinstall it and give another update!

[bogdonj]

whats the best grease to use to pack the U JOINT?

[pat in Santa Cruz]

what about the torque tube roller bearing behind the speedo drive?? Something is allowing the U joint to contact the side of the inner housing. I would guess the driveshaft is wobbling due to some bearing trouble in the torque tube. It would not be unusual for both that bearing and the rear main shaft bearing in the transmission to be worn.

[Patrick L.]

U-joiny grease.. Some folks like John Deere cornhead grease, others like a low pressure grease.. I make up a 'slop' of heavy oil and grease.. If the rear bearing is not sealed then transmission oil should mix with the grease so the cover plates should not be dry..

[bogdonj]

Originally Posted by pat in Santa Cruz

what about the torque tube roller bearing behind the speedo drive?? Something is allowing the U joint to contact the side of the inner housing. I would guess the driveshaft is wobbling due to some bearing trouble in the torque tube. It would not be unusual for both that bearing and the rear main shaft bearing in the transmission to be worn.

Your right.. I checked the roller bearing and there is no sign of play.. its pretty solid in there and doesn't make any noise... what else would I check to see if it was bad?

[bogdonj]

I'm guessing this is the bearing? If it was bad would there be movement in it? I notice a snap ring holding it in and the speedo gear underneath it.. what else is there to look at? Might as well look at everything while its out!

[Tom Wesenberg]

The marks inside the bell might be from a U-joint that went bad many years ago and was then fixed. I have a bell like that also in my spare parts.

[columbiA]

Stick a screw-driver under the DS at the bell & see what side-to-side play you have.If badly worn,the speedo drive will be worn too.

[pat in Santa Cruz]

ColumbiA is on the right track with the screwdriver method of checking play. The tension in the drive shaft can fool you into thinking its all ok because your hand strength is insufficient to move the shaft. I would take it all out as you say, while you have the chance and look at it. Doing it twice is a bummer. Behind the snap ring is the speedo drive gear, a spacer, the roller bearing, sleeve and finally the seal. The race is snapped into the tube. Tom has a point about the witness marks in the housing being possibly from the past. But the bearing could be bad, or the shaft could be worn and only a good visual inspection will determine that. A dry bearing makes a horrendous noise, and your housing looked pretty dry. When re installing the sleeve, be careful to line up the detent correctly, or you'll be sorry. Well, not really sorry, but the work involved to remove it again is a real PITA. Tom Endy has a neat trick for re installing it in his rear end treatise posted on the Orange County Model A site.