knob wont fit umi short stick but will fit stock stick fine...

[redsoxsstink]

i bought a knob off a website it said it would fit a stock shifter, ok awesome i had purchased and a umi short stick which is the same size in diameter as the stock shifter. great so the knob should fit perfect, but it doesn't. it wont screw on, well it will but i would have to wrench it on and when i do i can only get in abt a quarter of the way down. it cant be knob because i tried the knob on the stock stick and the original stick for the pro5.0 shifter and the both fit perfect. and my stock knob fits on the umi stick too. so now what should i do? i have a knob that fits 2 stick but not the one i want it to work on

[deadtrend1]

Call umi and tell them their threads are wrong on their stick. And wrenching the knob on may have destroyed the threads on that too.

[redsoxsstink]

how could i make a case on there threads are wrong, it fits the stock knob like they said.

[BonzoHansen]

And wrenching the knob on may have destroyed the threads on that too.

lesson: more force does not make mismatched threads suddenly match.

[redsoxsstink]

lesson: more force does not make mismatched threads suddenly match.

ok.... well why would my stock knob fit on then? and why would it work fine with every other stick i have?

[BonzoHansen]

You have to inspect & measure threads. I have some nice thread gauges with my tap set. it sounds like you had bad threads or you maybe cross threaded it.

[redsoxsstink]

You have to inspect & measure threads. I have some nice thread gauges with my tap set. it sounds like you had bad threads or you maybe cross threaded it.

cross threaded? how could they be bad if every other combo works fines cept the new knob and the umi stick

[sweetbmxrider]

obviously there is something wrong. i'd grab a flashlight and really look at each individual thread on both the knob and the stick. the slightest imperfection can **** up the whole engagement. there is probably a burr in the knob and the umi stick isn't perfectly threaded like the stocker. just my guess.

[V]

it could be an issue with the tolerances of the pitch of the threads....

the stock stick and 5.0 could have loose tolerances when it comes to the thread sizing and pitch.
the stock knob could have a loose tolerance as well since it a mass produced part.
the UMI stick may have tighter tolerances due to be a smaller/more controlled production run.
and then finally, the new knob may have tighter tolerances as well being a low amount produced at a time.
in the end, 2 items with tight tolerances will be harder to match up.

this could very well be the issue you're running into.

finding out the exact thread size and pitch of the UMI stick would be the first step and then find a tap for that size and go to town on the new knob.

[redsoxsstink]

it could be an issue with the tolerances of the pitch of the threads....

the stock stick and 5.0 could have loose tolerances when it comes to the thread sizing and pitch.
the stock knob could have a loose tolerance as well since it a mass produced part.
the UMI stick may have tighter tolerances due to be a smaller/more controlled production run.
and then finally, the new knob may have tighter tolerances as well being a low amount produced at a time.
in the end, 2 items with tight tolerances will be harder to match up.

this could very well be the issue you're running into.

finding out the exact thread size and pitch of the UMI stick would be the first step and then find a tap for that size and go to town on the new knob.
wow what a awesome answer. that is probably what i the problem is, how would you go abt finding the pitch?

[sweetbmxrider]

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