Aftermarket MT shift knobs

Wave 1, en route.

 

One of dems mine

 

MINE

MINE

MINE

 

Just a quick heads up for everyone. Installation will be the same as stock, with two exceptions.

I couldn't create the thread the way they do in the factory, but not for lack of ability ... it is for good reason.

Toyota clearly uses a plug tap, which is a tap that has a taper lead on the end of it.



This creates a taper at the bottom of the threads inside of our stock knobs, kinda like this ... (the threads should also taper with the hole in the following picture, but my modeling software won't do it for some reason). Anyway, this should be enough to show what I'm talking about.



This is the reason why we get a full turn with a tightness that will hold the knob in place while we drive. Considering that my knob is metal, and not plastic ... this tightening effect is a bad thing. If I did that, somebody at some point would get their knob stuck on their shifter due to the aluminum galling against the steel. Plastic on metal, there are no worries of this happening.

I used a tool much like this to cut the threads,

so it's dead straight the whole way down to prevent a galling situation. BUT, now we have to stuff some neoprene washers (or something that would be easy to get out later)down inside the threaded hole to compress between the knob and shifter a bit to give us the same effect. I also made the threads to the looser side of the tolerance to allow for some debris particles that may find their way into the thread over time.

It would also be a great idea to put a dab of grease (rated for aluminum) on the shifter thread ... just in case some foreign matter gets in the threads at some point. Best to give it something to slide against, rather than create a potential galling situation.

I probably over complicated that, but those are the reasons I made it the way I did.

 

Should I use aircraft grease? I have access to a few different types. To my knowledge what we use should be sufficient, I've used it on many different scenarios including building ar uppers. Also, did you supply the washer to shove in there? If not I may have a few ideas to fix that issue.

 

Yep, that grease will be fine.

I didn't supply anything, because I figure somebody might figure something out better than I would for that. Whatever it is, will probably cost less than .35c at the hardware store. I'm currently using a ripped up/twisted paper towel, kinda like something you would use in a bloody nose haha. Once a more permanent solution is figured out, I figure that will be easy to get out.

The hole diameter for the thread is 27/64"(.4218" or 10.715 mm), and I'm wondering if a rubber/silicon sphere exists to fit that snugly enough to where it does not fall out. I'm interested to hear some ideas.

 

So grease it up. And whats this about some gasket?? Can you post pic of example?

 

Exactly!

 

Yea ill figure something out when in hand.. I've got a bunch of small plastic and rubber washers/grommets can see which will be best and if I find a great solution ill post it here. I'm thinking a plastic washer would be a better solution, mainly because it will create a smash effect and should come out easily with the right size.

 

Here's an illustration. Without some sort of gasket, the knob will likely not orient the way you want it to,because all of our shifter threads have different start points due to Toyota's manufacturing inconsistencies. My shifter, all threads will be the same ... with the same start point (one benefit of milling them). It will also come to an abrupt stop with no way to orient it. So, for example ... say we have a silicone sphere to put into the hole ... the shifter will crush against it providing back pressure onto the threads to give a zone of resistance for proper orientation while locking it in place with enough force.

It does not have to be a sphere, this pic is just for illustration. It can be anything really ... as long as it works and you are happy.

 

Yep, and the thread pitch is .0492 per rotation. So, if you are half a turn to proper orientation, a washer with .422 OD that is about .025 thickness(or .075) will get you perfectly lined up ... theoretically speaking.

Of course the amount of crush will have to be accounted for. As well as if the OD of the washer is sunken into the drill point taper if it is under .422 dia ... and then there's the chamfer on our shifter that might allow the shaft face to be past the bottom of the hole in the knob. If I was thinking during development I would have made the bottom of the hole completely flat, takes out quite a few variables when trying to orient.

 

I got the non-engraved shifter so this won't apply to me since orientation won't matter?

would I be able to find some grease for aluminum grade at HomeDepot?

 

It will matter to a degree, but less so without engraving. The boot connector needs to be within a margin of orientation, or it will twist your leather boot.

This is what I would grab here ...

$7 Permatex 81343 Anti-Seize Lubricant, 1 oz. Tube , White

https://www.amazon.com/Permatex-81343-Anti-Seize-Lubricant-Tube/dp/B0002UEOLO. Home depot, or even a department store like WalMart/Target should have it as well.

 

If this helps, found different rubber balls on McMaster-Carr. Sizes 3/8" & 7/16" (available) are just either smaller or larger than the 27/64" stated. Searched their site for "rubber balls"

 

7/16 can definitely work with a little modification. Thanks!

 

Too much work... on the aftermarket trd balls, just stuff some paper in there. You don't want it to be easily compressed too much otherwise it'll settle after a few months of usage at a new rotation. Or.... A dab of loctite blue.

 

Anything worth engineering, is worth over-engineering ... haha. The paper and loc-tite will undoubtedly work, but after thinking about it I want people who bought this to feel like they have a more refined solution.

In a previous post, I kinda touched on the drill point angle in the bottom of the thread ... and how I would make it a flat bottom if I were to do it over again. This feature creates a "zeroed" surface to shim from, if you will.

I had some teflon laying around from a previous project (that I completely forgot about), so I made a little filler plug for the bottom of the knob. It doesn't compress much at all, but it gives a great surface to shim from.


I put that teflon pc in my SR ball, and it was off by 1/4 turn too far. 1/4 of the .0492 rotation is .0123, so I cut up a pc of .015 plastic shim to lay down there to allow for some tightening ... lines up perfectly now. I can make enough plugs and provide a shim kit to anyone who has ordered already, and would like to use this method (for free, obviously). As for the rest of the knobs, I will have to order more material!

shim stock (In the kit I can provide .005,.015,.030). Once the solution is found, they can be held down there with a dollop of grease or even some rubber cement). Alternatively, you could just lap the surface of the teflon plug down to a size that will work without shims. Although, I feel like getting it back out of the knob will be a chore. I could have threaded the plug and milled a screwdriver slot, but honestly that is just way too much work for such a trivial issue (That, and I don't think the threaded PTFE at this fine of a pitch would stand up to the forces of tightening).


The rest of the knobs, ready for engrave and polish.