A727 Narrow Bushing Front Clutch Retainer Conundrum

[12many]

I’m going through a refresh on my 67 A727 that includes swapping out the original 3 friction drum for a 4 friction drum (in order to run 5 thins) and just received it from A&A. The bushing has been installed slightly proud of the bottom chamfer vs flush with bottom chamfer (as shown in various manuals) but my original 3 friction drum with its original factory installed bushing has it installed a little further into the bore beyond that chamfer.
The last time I rebuilt it, after checking and adjusting endplay, the 3 friction drum bushing pretty much fully rides on the reaction shaft.
Now with the 4 friction drum bushing installed, as it is, will have less engagement with the shaft, regardless of what selective thrust washer is used to set end play.
I’d think installing the narrow bushing initially for mock-up in order to set endplay, then driving it further as needed so there is full contact with the shaft would be a good idea? More load carrying or not a concern??

Factory original bushing/3 friction drum:

4 friction drum as received with pump shaft installed:

Bushing installed in 4 friction drum:

3 Friction drum with pump shaft installed with thrust washer for correct endplay:

Manual (Carl Munroe book) Instructions for Bushing install:

 

[CudaFactHackJob]

Neither one of them is deep enough. Check clearance by removing front thrust and see how far the drum will fit onto the pump.

 

[12many]

4 friction drum fits onto the pump (pump casting just drags on drum) with no thrust washer, pump shaft is essentially flush with the bushing. I need to either source a correct sized driver or fabricate one and drive it in further, so I get the full width of the bushing riding on the shaft vs. in this case way too much not. I wonder if A&A used a factory bushing driver and that’s where it ends up, or if they used some other driver and eyeballed it? Not much I can do but make it right myself

 

[CudaFactHackJob]

If you want it done right...But just find a steel disc or something the same as the outer diameter and then tap, tap, tap...no need for a press or fancy tools. I always use a forward clutch bottom pressure plate flipped over in the three plate direct drum to run four thicks; or five thins. It's lil twisty gettin the snap ring in there, but it will go.

 

[12many]

Tap, tap, tap as you said and voilà!! Got the bushing further in to a starting point using .124” (2 washers) and can just tap some more if needed when I get to setting end play. Looked all around the garage for something.....found this old Offenhauser carb thingamabob up in the attic and lo and behold it is dead nuts perfect!
Never throwing anything out pays off.
Yeah, I can rebuild transmissions, I even have my own tools! Am I hired??

With two .062” thrust washers:

The “Proper Tool”:

Bushing driven in more:

With a .062” thrust washer, the bushing contact starts right at the pump bevel:

No thrust washer, pump fully engaged

 

[CudaFactHackJob]

Dang, it looks almost like you could use a wide bushing in there and just trim it off a little bit... but that 's a real pain. It's all about where the drum rides after the endplay is set. I shoot for .020 on a cold case. They shrink down a lot when cold, the thing will lock up stuck if you set .020 on a hot day (100 deg) then come back and check it when the temp drops to 60 degrees.