Worn transmission parts?

PeteVS

PeteVS

Well-known member
I have Mac's transmission book and he tells what to look for when looking at transmission parts, but is there a source of what DIMENSIONS should be? What I'm concerned about are surfaces that contact bearings-

OD of front end of main drive gear where it goes into the pilot bearing?
ID of back end of the main drive gear where the main shaft goes in?
OD of front end of main shaft?
ID of cluster gear?
OD of cluster shaft?

Case in point: A transmission I have apart has corrosion on the front of the main drive gear. Can this be ground to a smaller diameter? If so, how small? It's sloppy where the main shaft fits in. Is this bearing wear or wear on either of the two pieces? The cluster shaft looks good. Is it? Etc, etc....

Also, is there a quick way of telling if synchros need to be replaced?
 
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PeteVS said:
I have Mac's transmission book and he tells what to look for when looking at transmission parts, but is there a source of what DIMENSIONS should be? What I'm concerned about are surfaces that contact bearings-

Also, is there a quick way of telling if synchros need to be replaced?
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What I have done in the past was E-mail some close-up digital pics that I took of ****** parts to MacVP. These parts either had questionable wear and/or I didn't know the year of manufacture. He then did his best to determine if he thought they were ok visually or identify the pn/year they were made. You might want to check with him and see if that would be ok to do now. I have never dealt with Charlie NY so don't know if he would also be willing to do something like this or not. JM
 
JM 35 Sedan said:
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What I have done in the past was E-mail some close-up digital pics that I took of ****** parts to MacVP.

Seems like a bit of an imposition to expect these guys to verify the condition of your parts. Would have to be some great images to be useful unless the condition of the candidate parts was screamingly obvious. If the Guru say to use them and they make bad noises then they can be considered at some fault. If useable parts are condemned, well... Trans building is a judgement call with a need to examen the parts in a good light with a bit of feel for burrs on the cluster's first gear, and look for abnormal wear. On the main gear, that front that goes into the pilot bushing is commonly worn. There was a metric bearing of smaller ID that guys use but since survivorship of those gears is so high, replacement is much easier than turning the hard shaft. The synchro rings are so cheap that new is the safest choice. The alloy on the newest Chinese rings may not be too good so guys with, access to old ones may save the best of the good used, often those that were the third gear ring, for their own use while the cheap stuff goes to those impressed by something new. My recently assembled trans in my '47 is a collection of best looking parts seen lately and it still is not dead quiet. The snaggle tooth mess that came out of the car was probably quieter. The old synchros worn near smooth still functioned most of the time. Good Luck: Fred A
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Let me rephrase this...

Does anyone have drawings or other information indicating what the part diameters should be (what did the factory specify?) on the surfaces that ride on or in bearings? I don't expect anyone to diagnose my parts by photos or anything like that. I just want to know that if my part measures 1.000" and it's supposed to be 1.005 +/- .002" that I should forget about using that part or if it's supposed to be 1.000 +/- .001, I'm good. Also, there should be a "feeler gauge" dimension for the gap between a synchro and its hub when they're assembled. I figure that if a synchro hits on its flat surface before the cones engage, that's bad, but if there's say a .030 gap, is that good? Does this make sense?
 
This was the only thing that I had on the specs for the different gears. Ed
 

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Here's Ed's picture, blown up a bit.
If you get a Red X, just click on it to open picture.


4782

 
Finally a useful number,

as if I had provided any. You could do scores of these transmissions without needing any of these numbers except the second gear thrust washers (7069) that come in two thickness to take up some of the end play of the main shaft assembly, keeping the trans from coming out of second or high. If the main gear is worn at the pilot, they still have some of the original diameter and then a worn central area making a poor center for the shaft. Good Luck: Fred A
 
Thanks guys!!

This is the info I was looking for. By the way, what's the source of the pages with the numbers?
 
Pete, that came out of a copy of a Ford Motor Co. Repair Manual "Transmissions, Clutches, Overdrives, and Power Take-Offs 1932-1947" that I have. It is dated June 17, 1947. Ed
 
Ed Pitts said:
Pete, that came out of a copy of a Ford Motor Co. Repair Manual "Transmissions, Clutches, Overdrives, and Power Take-Offs 1932-1947" that I have. It is dated June 17, 1947. Ed
Click to expand...

Ed: Thanks so much. Now, all I have to do is find a reference librarian here in North Jersey with a copy of this book so I can peruse it! (Are you listening Bruce?)
 
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