'67 FORD 4500 TLB POWER REVERSING TRANSMISSION- PISTON IS CRACKED

[Sasquatch270]

Yeah I just checked my manual it must be the kind that came with it in that year..... it's roughly 4in by 6in surface area submersed at least 6 in in fluid..... I'll know for sure when I redo the pump test LOL.... and yes I could not find a picture of the sealing rings either but it was the only parts that were left in the seal kit I bought that matched the bottom ring in my picture.... the one below the ridiculous rubber o-ring -which I guess if I lived in Alaska would be okay

 

[Check Break]

Back to the 5/8" sealing rings. Unfortunately I have little recollection of where they go, and remember only that they're fragile. After looking at your picture and the shop manual, my lack of memory makes sense. There's nothing to worry about. Just don't break one on the way back and if you wonder if you broke one, maybe you did so back up and take a look. Spent a few minutes looking at the oil flow diagram in the front input shaft with respect to your o-ring. After cogitating on it a bit, I don't think it's the source of your reverse problem. Seems to me it would affect Forward more than Reverse. Another reason to make sure you blocker valve bores and pins are spotless and the springs aren't broken or out of spec.