Here is the question. I also attached two photos.
Just an update and another question. I solved my original problem with the clearance of the first & reverse brake pack. I took the entire thing apart again and then used the largest plate in the OEM list (5.4-mm) and it worked out fine. I am very happy with that outcome. But I have encountered another clearance issue and question.
There is another clearance measurement requirement between the sun gear input drum and the direct clutch drum. The FSM says this distance should be between 0.209" to 0.287". It also says to use a vernier caliper for the measurement, but I found that not a workable option, so I use a stack of various thickness feeler gauges, which ought to be at least as good as using a vernier. It is a simple measurement, and mine comes in at 0.190". I have taken this thing apart maybe 10 times now. I can now do it in my dreams, but no matter what I do, what I check, or what I measure, it always comes out at 0.190". When I did the original disassembly, I took a photo of this area as part of my documentation. I have attached this photo below along with the same area today. I am not seeing an additional 0.019"+ in that original photo. Has anyone else made this measurement and found it within the FSM specs?
See Step 10 in the assembly procedure; yes, feeler gauges are acceptable.
Your problem is related to the fact that you're using non-Toyota clutch plates and steels, and they don't have the same thickness tolerance that the OEM parts do.
This situation is much more complex than your first, or third, questions. The forward and direct clutches have a multitude of clutches and steels, making a stack tolerance problem likely. It's really time consuming to check every part and every bore depth and do the math to make sure that the clearances are likely to work, rather than to just require vendors to make parts the correct thicknesses and use them as gauges during the build. This was Toyota's plan for inital (assembly line) assembly.
To answer the question you didn't ask, "will this be OK?" it depends on how much gap there is between the drums and their bearings once assembled. There has to be intimate contact, or the bearings will fail. You likely won't have too much compression, or the snap rings won't fit into their grooves.
The only way to know for sure is to take everything apart, measure the height of the bore between the snap rings (you'll have to construct tools for this, unless you have access to a CMM) and then measure the overall assembled heights, taking care to note whether the bearings will have direct contact on both sides when assembled. It can be done, but it will not be quick.
If your offset was 0.002" or 0.003", I'd say let it go, but 0.019" is a lot and enough that one, or more, bearing isn't getting full support. The solution may be as simple as a 0.025" shim under a bearing, or a couple of shims totaling that much, to get you to a middle range target between 0.209" and 0.287". The reason you are instructed to make this check is that, in addition to the subassembly stacks, the two clutch assemblies also sit on each other, and there is no provision in the machining to ensure there is no possible failure. You can thank the accountants for that.
The decision will depend upon whether your intermediate measurements of clutch pack clearance during the direct and forward clutch assembly builds were within the acceptable range(s) or not. If they were not, that's where the shims need to go. If they were, then all you need is a shim behind the direct clutch.
» NOTE: any shims should be soft metal (not hardened) and be placed between the (plastic) thrust washer and the (soft) drum, not between the thrust washer and the (hardened) bearing.
This, by the way, is the root cause of the 2000 year model A343F failures in the 100 series. The tools used to measure the snap ring groove offsets were wearing and it wasn't caught in time, resulting in too much slack in the overdrive stack and an unsupported bearing. The bearing failed prematurely and the resultant wobble casued the overdrive assembly to fail, resulting in total unit failure.
Feel free to PM me if you want to discuss directly (I know conversation-by-text is problematic at best), otherwise, let's keep this topic open for the good of the group.
