ZT-3100 Vent Plug Hex Size?

logan01

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Did my first transmissions fluid / filters change yesterday. Insane. Never got the vent plugs removed. 1/4" seemed to be the size but had a tad of slop. Thought it might be 7mm but didn't have one. Broke three 1/4" allens and stopped with my fourth and last one as it was bending towards breakage. If I can know the correct size (Hydro-Gear tech support person, my dealer and a competing dealer, did not know the size :thumbsup:), I'll buy a stubby like those that insert to drivers and put a wrench to it. Only thing else I know to do is hit them with a torch which I really don't want to do near the belt and plastic pulleys. The two filters took close to 5 hours to remove. I went through 7 filter wrenches, two of which were only 2 1/2" diameter. They just wouldn't bite, even with some mods I did to them. Ended up using the filter wrench style that resembles a large set of channel locks. Took forever to fill the 2 trannys due to the burping through the reservoir process. So anyhow, does someone know the correct allen size for the vent plugs? Thank you.
 

ILENGINE

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From what I could gleem from the service manual the plug is question is a 1/4 inch allen torqued at 180-240 inch pounds. Under tools required it calls for a 1/4" allen socket.
 

logan01

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From what I could gleem from the service manual the plug is question is a 1/4 inch allen torqued at 180-240 inch pounds. Under tools required it calls for a 1/4" allen socket.
Good deal. Saw the torque values. Must have missed the size. Thank you.
 

motoman

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I feel your pain. On several occasions I have had to make an allen or square wrench due to corrosion, over torque by ham fisted operator, or just loose fit. Sometimes you can carefully reduce the next size by careful grinding (not overheat). I have also made them with hardenable steel stock in soft condition. When fit is perfect heat dull to cherry red and hold for couple minutes , then immerse in a little can of engine oil. Finsh grind if bigger after heat treat. Just did this on a Koni shock shaft tip.
 

logan01

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I feel your pain. On several occasions I have had to make an allen or square wrench due to corrosion, over torque by ham fisted operator, or just loose fit. Sometimes you can carefully reduce the next size by careful grinding (not overheat). I have also made them with hardenable steel stock in soft condition. When fit is perfect heat dull to cherry red and hold for couple minutes , then immerse in a little can of engine oil. Finsh grind if bigger after heat treat. Just did this on a Koni shock shaft tip.

That's a good deal. I'm considering making a couple myself. Just can't stand sloppy fits. But goodness, they sure do torques these things down initially. I'm even considering installing vent elbows up through the sheet metal if nothing is in the way. Wonder if someone makes remote filter adapters that size? Do it all from topside. :thumbsup:
 

ILENGINE

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Talk about torquing things, what I hate is having to replace the sprocket on a customers chainsaw, and have to heat the clutch, because they used red threadlocker on the crankshaft threads when they installed it at the factory.
 

logan01

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Talk about torquing things, what I hate is having to replace the sprocket on a customers chainsaw, and have to heat the clutch, because they used red threadlocker on the crankshaft threads when they installed it at the factory.
I hear ya. It's usually one extreme or the other.
 

logan01

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After researching and finding several positive comments, I ordered and installed Stens filters on the trannys. I immediately noticed prior to installation that the factory filters were noticeably heavier (stouter?) than the the Stens.
 
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