Ko-ken Wobble Fix Extensions
- Thread starter Ralf11
- Start date
Kind of, any reasonable amount of pressure forces the wobble into fixed status.
Kind of a pain when you need a wobble deep down somewhere and youre trying to push the socket onto the fastener and then it fixes straight ahead.
2ndGearRubber
Well-known member
Agreed. The knurling is great though. I broke a few 1/4 drive ones, I'd suggest snap on for ultimate strength. Only brand I haven't broke the head off yet, although I'm a heavy 1/4 drive user. Zero issue with my koken 3/8 standard extensions though.
IMO the fix for the tendency to pop into the fixed position is to use the ZEAL or impact-style universal joint, ball and socket design. I find this is the best design for allowing some movement (30* or so), while still allowing downward force to be applied.
Dave455
Well-known member
I’ve tried these (only in 3/8 drive) but I have to say that I don’t think I would have use for them.
Most of the time I need a regular extension. If I need some flex, then the 3771 Universal joint gives it. If I need more flex, or if space is tight, then I’d probably go for a universal socket.
I can use these accessories without weakening the square drive of the extension, or risking damaging the square drive of the socket!
Maybe as a tool to do everything, in a road box, they might be an idea, but then that’s what a I use my KoKen for and I generally get by with the universal,
Most of the time I need a regular extension. If I need some flex, then the 3771 Universal joint gives it. If I need more flex, or if space is tight, then I’d probably go for a universal socket.
I can use these accessories without weakening the square drive of the extension, or risking damaging the square drive of the socket!
Maybe as a tool to do everything, in a road box, they might be an idea, but then that’s what a I use my KoKen for and I generally get by with the universal,
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In addition to what noid mentioned (which is significant), you’re not going to get the same articulation from a wobble extension as you would with a universal socket/joint. So it’s a bit of an apples and oranges thing. But there are times where I just need a little bit of articulation and don’t want a U joint folding over, so that’s where I prefer the Koken, just get a feel for how much pressure you can apply before it locks. But if I could have only one, get the U joint first.
Agreed also. The knurling is incredible, and makes them worth it on that point alone.
Not surprised that you've broken a few of the 1/4, as I find the koken extensions to be thinner than most; great for access but not for ultimate strength.
For Japanese offerings, it looks to me like the Nepros line would have the best ultimate strength.
2ndGearRubber
Well-known member
Thickness seems the same as snap on, and sk. Gearwrench and my tetons are a bit thicker.
Agreed also. The knurling is incredible, and makes them worth it on that point alone.
Not surprised that you've broken a few of the 1/4, as I find the koken extensions to be thinner than most; great for access but not for ultimate strength.
For Japanese offerings, it looks to me like the Nepros line would have the best ultimate strength.
Shoot, those do look nice!
Did they break at the drive end/socket end or in the middle somewhere?
Any chance of tossing a digital caliper on your extensions? I'm not near mine, otherwise I would do it.
Considering the extensions act as a torsion spring, each mm should account for ~15-20% additional "strength".
2ndGearRubber
Well-known member
Mine are all at work, I can check monday. All of my wobble extensions of either design break at the thinnest part of the wobble, leaving a stump annoying stuck in the socket.
GrantCee
Well-known member
They're a neat idea and wonderfully made, but like others have said they have a tendency to lock (or unlock) when I don't want them to. I've also noticed the thin shafts seem to have a lot more "give" under torque than other extensions.
The standard Koken extensions have the same great knurling and build quality, but are significantly larger in diameter. They feel as solid under torque as any others in my box.
The standard Koken extensions have the same great knurling and build quality, but are significantly larger in diameter. They feel as solid under torque as any others in my box.
Wamsutta
Well-known member
I'd recommend skipping the wobble extensions and getting swivel sockets (or "flex sockets" as Snap-on calls them). With swivel sockets, you can use very long rigid extensions to get to an area remotely.
When you say standard are you referring to their non-wobble?
They also have the zeal extensions, but probably not the ones you are referring too considering they don't have knurling.
Also i'll drop this here for what its worth (specific strength numbers):
Fedwrench
ALLIANCE MEMBER
I don't think there is ever a reason not to buy a Koken tool 
As others have pointed out though, the wobble plus type extensions are a compromise between the two types so, I think you should get wobble and straight versions, and then pick up wobble plus as spares. That way you truly reap the benefits from each's unique design.
As others have pointed out though, the wobble plus type extensions are a compromise between the two types so, I think you should get wobble and straight versions, and then pick up wobble plus as spares. That way you truly reap the benefits from each's unique design.
pizza
Well-known member
i'm a DIYer
for my uses, i've decided that wobble fix is probably good enough for me as a do-all extension. i have plans to buy the PK3763/6 set eventually to replace my **** no-name chinese extensions.
https://palmac.net/koken-pk3763-6-offset-extension-bar-set-3-8-inch-sq-drive/
note that they don't give enough articulation to replace universal joints. i already have some of the koken zeal univeral joints (the ball-style ones) like 3771Z, and they're badass.
see also: https://www.garagejournal.com/forum/showthread.php?t=326332
for my uses, i've decided that wobble fix is probably good enough for me as a do-all extension. i have plans to buy the PK3763/6 set eventually to replace my **** no-name chinese extensions.
https://palmac.net/koken-pk3763-6-offset-extension-bar-set-3-8-inch-sq-drive/
note that they don't give enough articulation to replace universal joints. i already have some of the koken zeal univeral joints (the ball-style ones) like 3771Z, and they're badass.
see also: https://www.garagejournal.com/forum/showthread.php?t=326332
I don't think there is ever a reason not to buy a Koken tool
As others have pointed out though, the wobble plus type extensions are a compromise between the two types so, I think you should get wobble and straight versions, and then pick up wobble plus as spares. That way you truly reap the benefits from each's unique design.
Generally, Koken > everyone else for socketry.
They are the only ones who are playing outside of ISO tolerances (as in better/tighter).
Their zeal sockets have been
the dual type are pretty useless really.
the koken ball swivels are superb.
I use ball swivel and dedicated swivel extensions or dedicated standard extensions only .
Shame some of the bigger players don't do good knurl, snapon while strong are completely useless on ergonomics .
I have some german brands purely for satin finish and better handling design .
Even some better effort taiwan extensions are decent on ergonomic/finish and strength .
the koken ball swivels are superb.
I use ball swivel and dedicated swivel extensions or dedicated standard extensions only .
Shame some of the bigger players don't do good knurl, snapon while strong are completely useless on ergonomics .
I have some german brands purely for satin finish and better handling design .
Even some better effort taiwan extensions are decent on ergonomic/finish and strength .