Drive shaft piñon sleeve

[jdpalmer]

Can anyone tell me what the correct two dimensions are on the drive shaft bearing surfaces on the pinion sleeve

[Tom Endy]

The pinion sleeve diameter is machined to fit the inner diameter of the two pinion bearings that mount to it. The diameter where the first bearing mounts near the gear end is machined such that the bearing mounts with an interference fit. The second bearing should mount with a snug sliding fit. The difference between the two diameters is .015.

The purpose for this is so the first bearing mounts tight. The second bearing must have the ability to slide back and forth to facilitate the setting the pre-load.

The original Ford pinion sleeves are machined this way.

Reproduction pinion sleeves in later years did not take this factor into consideration and the entire sleeve was the same diameter, all interference. It makes it extremely difficult to set the pre-load. If you get it too tight it is almost impossible to back it off.

When I discovered this problem a number of years ago I made a tool from the end of an old axle. I had the end turned down so I could chuck it up in the 1\2" chuck of a drill press. This way I could reduce the diameter by a nominal .015 where the second bearing mounts using a file and the drill press.

I wrote an article about this problem and published it in the Victoria Association newsletter. Walt Bratton saw the article and called me and told me that he and Don Snyder are aware of this phenomenon and the R&P's they have manufactured and sell take this factor into consideration. From then on if I had to use a reproduction R&P I made sure it came from Bratton's.

However, as the years went by their supplier became sloppy with their tolerances. They may well have had a .015 difference in the two diameters, but the second bearing had an interference clearance. I had to use my crude machining technique in order to use them.

I would much rather use an original Henry R&P any day as I know I will not have problems with them. When I have to use a reproduction I am wary.

When you go to press the first bearing on a reproduction and as it passes the area where the second bearing mounts if there is a "crunching" sound, which is indicative of an interference fit, stop and pull the bearing back off and have the sleeve turned down in that area.

On an original pinion sleeve when you press the first bearing on it will glide over the area where the second bearing mounts. A soon as it hits the step between the two diameters you will hear the familiar "crunching" sound as it encounters interference.

To answer your original question the diameter of the sleeve is plus and minus .015 of the inside diameter of a new Timken bearing.

Tom Endy

[Tom Wesenberg]

Tom, did you mean to say .0015"?

[jdpalmer]

I do believe that is.0015 but did you write down what the first bearing fit measures like
1.571 or 1.570

[Tom Endy]

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One and a half thousandths. .0015

Tom Endy