Shift rod diameter

[Mnmunky]

Quick question to all of the resto buffs and knowledgeable owners out there…

Does anyone know the OD of the shift rod, that is held up by the bushing near the gear stick?

I need to make a split version for my car, as I can easily print things and need to replace mine (it has no bushing in there at the moment and it seems such a pain to take the entire assembly out through the front).

Thanks!

Kester

[Era Vulgaris]

The shift rod bushings are already split. I've replaced them without taking the entire shift rod out before, but it's kind of a PITA. The difficult part is getting the bushing to seat in the hanger since it can't compress, since the shift rod is in the way. Then you need to open the retaining ring to fit it around the shift rod, like opening a keyring to fit a key, only way bigger.
It's really not too bad of a job to pull the shift rod out, and if you do it's way easier to install the bushing and retaining ring. Just loop a really long length of string through the end of the rod before removal, then you can pull the string to guide the rod back through the hangar and bushing when you re-assemble.
_________________
Currently own:
66 Karmann Ghia, L390 Gulf Blue, under construction, here: www.thesamba.com/vw/forum/viewtopic.php?t=760505&highlight=
99 Mazda MX-5 10AE, Sapphire Blue Mica, 6 speed, LSD

Previously owned:
98 Porsche Boxster, silver, 2.5L -- 67 Karmann Ghia, Black, 1500sp -- 98 BMW Z3, Atlanta Blue Metallic, 2.8L I6 -- 75 Porsche 914, Laguna Blue, 2270cc -- 72 Porsche 914, Signal Orange, 1.7 FI -- 74 Karmann Ghia, Black, 1600dp -- 74 Triumph TR6 with O.D., sapphire blue

[Mnmunky]

Thank you for the great reply!

I’m not looking forward to clearing everything out of the way, so that I can get the rod out. It looks like the frame head panel might be trapped by the front beam and knowing my luck, whether it’s something as simple as the car horns, or some other piece along the way, I’m going to strip or break a bolt. Dropping the front beam to do the shifter rod, would be a nightmare!

If I can just work something simple out that I can print, then for now, it might be the easier solution.

I took the gear lever / shifter off last weekend, to find that the bracket that the shift rod passes through, wasn’t attached to the tunnel any more. No bushing at all either (it’s probably in the tunnel somewhere). Trying to get the shifter back on, with the bracket captive nuts essentially being free to float anywhere, was a mini nightmare! At that point I didn’t realise that the bracket should be welded, and the T shifter had some fine screws, one of which wanted to strip the head, rather then loosen.

I needed to move the car, so my wife could get her car back in the garage (due to the huge amount of snow we have in Minnesnowta), so leaving it where it was - essentially disabled (it was in gear with no shifter connected) wasn’t an option.

I had to use string to hold the bracket and shift rod ‘up’ and in place, so I could get the bolts back into the captive nuts, and the carefully pulled the string out, before the bolts squashed and captured the string in place. It took three long and frustrating attempts, once I figured out what was wrong!

I think I have a couple of ideas, of how to create something that should snap fit together for the linkage bushing. Just need to work out the sizes to print. If it works, I can then share it on here, so others can print there own and save some of the challenges of this design!

I will weld the bracket back on, but for now, I thought that if it was loose, it might help me with the development of the idea.

I have bought a new bracket, bushing and ring. I don’t think I will need them if my idea works, but they will help with the idea development / testing.

[74 Thing]

This 2 piece unit is available:
https://www2.cip1.com/c24-111-701-259-akit/

https://www.youtube.com/watch?v=0FtgmQUQB4I

[Mnmunky]

[Mnmunky]

A Google image search found the original maker.

https://car-layers.com/en/products/vw-kafer-schaltstangenbuchse

I’ve sent them an email. There’s has the advantage that it’s proven. That said, it’s always more satisfying if you can fix things all by yourself! :p

Edit: I like the grub screws as well. Not only help you hold the part, but are magnetic too. Very clever!

[Mnmunky]

Using a lot of different search terms, the closest I have found so far is ‘just over 22mm’ from someone else asking the question here:

https://www.thesamba.com/vw/forum/viewtopic.php?p=6368803

I’m going to scale up the parts in CAD today (the others are estimated guesses - so little more than a sketch) and make sure that I can change the size in the model easily.

Will probably print three or four different sized parts around the 22mm diameter and then measure when I go to fit it and choose one.

Let’s see if I can get some good CAD time in this weekend!

Anyone think I need to add a similar pinch thread point as the cip part? Or other thoughts about the design before I get going?

Thanks!

[Mnmunky]

So I’ve started measuring parts up and have drawn two sets of components - one for a 22.25mm diameter shift rod, the other for a 22.50mm shift rod.

Printing will not be amazingly accurate anyway, so it’s going to be measure the printed part / measure the rod and use the closest of the two.

Will print them on Monday, which will give me a couple of nights to sleep on the design. I’m thinking about adding the grub screws for holding / magnet like the cip part. It’s just an added hole that can either be tapped or self tapped.

Any thoughts?

This is where I stand now:

[Mnmunky]

I’ve realised that the leading edge of the design, relies on the thicker U shape part to deform to clip over the one way location ramp.

As this is going to be a printed part, I can make these longer, by taking some more material out of the side wall next to the clip over ‘ear’.

I’m also thinking of adding a very small radius to the leading edge of the internal of the bushing bearing face.

[Mnmunky]

A quick break from painting the basement and tweaked the design to have more flexible ‘ears’.

Guess I better print it tomorrow to see if it does clip together how I think it should…

[Mnmunky]

One step forwards and two steps back!

I got the first parts printed today.

Here they are with the support material still on them. This is from our lower resolution printer, but I wanted to check for any issues.

Support material cleaned up.

And a quick test fit.

I realise that the window opening isn’t wide enough (or the snap ramp is too wide). It’s a bit too tall as well. I think I might struggle as 3D printing tends to have a weakness in the grain direction - where the layers build up on top of each other.

If I print in the best direction for the thinnest area around the bracket, then it’s really in the wrong direction for the flexing clip. And visa versa.

I’m going to try a few tweaks tomorrow and failing that, resort to using a spring clip I’ve just found at the hardware store! That would be a shame though, as I like the idea of a print only solution.

One of the techs at work asked me why I just don’t zip tie it. I told him, I couldn’t bring myself to do that. He asked me who would know? I told him I would!

[Mnmunky]

I’ve made some minor mods to the bushing today and also quickly modeled a ‘Plan B’ option that includes the clip.

Two of each went onto the platter for the good printer tonight, so should be finished in the morning.

[Mnmunky]

Well, I finally have two concepts that look like they should work.

Not sure which I’m going to use though.

I printed them on a better quality printer, though the carbon fiber filament printer was busy, so it’s on a high res printer.

The first one, is the self clipping one that I have been working on since the start of this thread:

And the second is plan B which uses a metal clip, over the top of the two halves to hold it together.

I haven’t decided which one to use yet. The first has the advantage, that it just holds itself together and has more wall thickness for wearing in general (though the section around the hanger is identical on both. The down side is that the clip material is untested - will it last 5 years of use?

The plan B has a thinner section where the clip is, making it possibly more likely to wear, but I imagine that as the clip material is metal, there are little concerns about its longevity of holding together.

I won’t get to fit them for a week or so, as I have other weekend work to do on houses first, which will give me time to think!

I printed 2 of each, so there will be three going spare if anyone wants one and I’m more than happy to share the file, if you want to print your own.