Vanagon – minor transmission work.

Small stuff. First off, I changed the transmission oil from the Castrol gear oil that I put in back in 2011. This time I’m suing Swepco 210. Lots of discussion about gear oil on the Samba, Swepco gets a good rap, many are running 201 and more recently more are using the moly containing 202 or 212.

So after 6 years and over 100,000 km the transmission plug magnet looked like this. Not too much swarf.


The second thing I did was to add more holes to my homemade transmission skid plate. Blog post about original install here. Yes, the relative lack of ventilation holes finally got to me. Even though I live in a very temperate climate, and I don’t do many long distance hot weather high speed trips, I knew I should have more air going over the transmission. Drilled more holes ( and didn’t measure spacing, but no one is going to see that are they?) and also put in some slots. And as I am always game for a questionably valid idea, I put in a bit of plastic hinge material art of the slots and infront of the holes.


Here’s my thinking. The plastic strip will create a little bit of high pressure in front which will help direct air flow up into slots, the strip also will trip the air flow and make a lower pressure area directly aft of it. It’s all pretty shaky fluid dynamics but what’s the harm in trying?

Green is air flow, gray is skid plate.


Yeah, laugh it up 🙂

The last thing I did was adjust the ball and cup part of the gear shift linkage. The parts circled here.


But what adjustments can you make with that assembly you ask? I didn’t think there was any, I was thinking the fit of the ball into the cup was worn and loose. This supposition was a little bit of a Hail Mary wish, I had been having some shifting issues. The first to second, and the third to second shifts had been getting harder over the last few months. It felt like the linkage was hitting a stop rather than anything internal with the transmission itself. The low hanging fruit was this part of the linkage and I thought I’d have a look before working forward with adjustments to the rest of the system. 

I think the specs for the ball and cup are that the cup has an ID of 30mm and the ball OD is 29.6mm. I was wondering if things were worn out and the fit sloppy. You can buy replacements. And also I was wondering if the splines on the ball part, where it fits in the splined shaft in the transmission, were worn.

Going at it I remembered that a previous owner had made a modification. The lower part of the cup lever had been cross drilled through the horizontal shift rod and tapped and nutted. The stock method of securing the cup lever to the shaft is a small roll pin coming up from the bottom. The red arrow approximates where the cross drilling was done.


Took the parts off and the cup and ball fit wasn’t that loose at all. But without the added cross bolt the fit of the cup lever onto the shaft was very wobbly. When I tightened up the cross bolt the fit became very secure. And miracle of miracles, tightening that bolt cured my shifting issues. 

It would be a little bit of a chore to drill and tap the connection on the van. I think this was done when the transmission was rebuilt ( the previous owner mentioned, but had no paperwork proving, that the transmission had been rebuilt). Maybe this mod could be of use to some of you out there. It’s something to be aware about if you are putting on a new cup lever, check the fit on the shift rod.

  1. #1 by edbee on May 27, 2017 - 9:51 am

    Interesting as always 🙂 and a good tip about the fit of the shift lever on the rod. As far as the skid plate goes: I’m thinking you could rig up a temporary wind tunnel, add some smoke so you can see what’s happening, and test the effect of that piece of plastic. I’ll bet it helps a bit but maybe a slightly larger one would work even better. (and if it gets ripped off on a rock or something, it’s easy to replace) Cool 🙂

    • #2 by albell on May 27, 2017 - 10:41 am

      Hi Ed,

      I’ve had a little experience with making water tunnels. Not big enough for full size test though 🙂 Obvious thought is a camera mounted underneath van, a series of nozzles and tubing to smoke generator, and a test drive. That ain’t gong to happen is it 🙂

      Yup, a bigger plastic strip would be better. But this bit was given to me by good friend Stephen so availability and convenience trumped. It’s held on by three 1/4-20 stainless screws, skid plate which is 3/8″ aluminum drilled and tapped. No helicoil, just the aluminum threads. Pretty well a throw away idea.

      Btw, I can’t recall if you told me or blogged it, but did you use swepco in your syncro ?

      Cheers

      Ab

      >

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