esde - 2/23/2005 7:53 AM
So which trans is the g series and which is the f series?
OK - I have to warn you, I'm no expert. But I do have all the data in both the repair manual and the tech data book... [

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I think the different versions of the UG 2/27 trans simply were modifications of the original design. They were phased in to the assembly line at some S/N. I have no idea which SN or date, but your favorite Mog parts dealer should have that info. That's why it's so important to have all your numbers when ordering parts.
There is also a UNIVERSAL HOUSING which can replace any of the series, but sometimes modifications must take place to both the universal housing and the attachments which go on them (weld up holes, bore/tap new holes, ect).
There was no difference in main transmission between the 6-speed and "20-speed". The multiple ranges came from the addition of a special cascade unit onto the front of the UG 2/27. The main box was identical. I'll go out on a limb and say that *any* 6-speed UG 2/27 can have a cascade box attached (except a truck with a torque converter, which fit's in the same place).
To further address your original question, I have looked at pictures and drawings of both the single speed PTO and the shiftable PTO. Both units APPEAR to have the exact same housing casting, with all the same mounting holes. The single speed PTO even seems to have the hole for the shifting shaft from the two speed unit. The only real difference between the two is the dual speed PTO has a sliding shaft on which there are two gears instread of a fixed shaft and one gear.
So, your real challenge is to figure out WHICH transmission housing your two PTO's came from. I don't think the PTO is too hard to remove. With no good info on the PTO's origin, I'd simply remove the single speed unit and carefully compare it's housing to the two speed. If the housings match up and all the holes are the same, my guess is you would be good to go. If there is a missing hole or mis-aligned hole, it's a good chance you can modify the PTO housing to fit.
I hope all this makes sense [

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