742 case question

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mean318

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I have recently bought a complete 742 case unassembled and I am trying to build it up but I don't think all the parts are there. I am used to working on 489 cases with the crush sleeve and I know my 742 needs a solid spacer with shims I have plenty of shims but I don't know if I have the correct spacer the spacer I have is about 1 1/2" wide and it does not go in between the pinion bearings it looks as if it were to go between the outer bearing and the yoke and it looks as if it would be a small type crush sleeve. I would actually like to see a breakdown of all the parts I need for the 742 case and how it would go together. Any help would be gratly appreiciated!!! Thanks
 
You do not need a spacer with the 742 because it is a stepped pinion, the 741 is the one that uses the spacer because the pinion is not stepped. All you need for the 742 is shims for behind the big bearing for setting pinion depth and shims for the outer (small) bearing to set bearing pre-load.

If you have never set up a ring and pinion before there will be a number engraved on the pinion this is the depth that the pinion needs to be at from the carrier bearing centerline. This dimension is probably the most important setting. You get this setting by adding or taking away shims between the pinion gear and inner (large) bearing. Being this bearing is pressed on it can be a royal pain unless you do this trick. I have an inner (large) bearing that I honed out so it just slides on and off the pinion. I use this bearing to find the shim stack that I need to get the depth right. Once I find the right shim stack I take a new bearing that I heated to 400 degrees in a toaster oven I keep in the garage and slide it over the pinion then let it cool naturally, DON'T quench it with water! let it cool. This way you don't even need a press plus I don't like using a press for assembly if I can help it, just disassembly. You get this dimension right your gear contact will be right.


Chuck
 
Thanks alot I have also made a inner "test" bearing for the pinion depth I was just wondering how to get the preload set so all I need are shims for the preload? Do they go in between the yoke and bearing?
 
For the pre-load the shims go between the bearing and the pinion step. The yoke goes right up against the bearing.


Chuck
 
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