A few years ago i tried re-bushing a spare throttle body using Delrin as the bushing material. I couldn’t get the throttle action smooth, it seemed as if the Delrin had a stiction property that I just couldn’t over come either by sizing the bushing or lubricating. So I laid the project aside and forgot about it.

Then this last summer I noticed some play in the shaft of the throttle body installed in the van. There was enough play to make adjustment of the throttle position switch very fussy. So i though back on my previous experiment and I thought I’d try making bushings again, but this time out of HDPE.

First let’s go back to my spare throttle body, the one I re-bushed with Delrin. I have a blog post here showing it before I started screwing around. I even went as far as cleaning up the wear marks in the bore and making a new butterfly plate to compensate for the now enlarged bore.

See the Delrin bushing?

And on the other side, the throttle position switch side.

My daily driver one on the left, the re-furbed one on the right.

Not the larger cam on the one on the left. This is the newer, revised throttle position switch system.

It appears like a lot of space around the butterfly, but it really isn’t that bad. I can’t recall the gap size (I measure with wire).

It kinda looked ok to me.

The dried up seal on one side.

And the other.

Wear in the bore from the butterfly.

I decided to leave bore and the butterfly untouched. I chucked up a hunk of polyE and turned and reamed a couple of bushings.

Recessed on the throttle position switch side.Why? because the switch plate has little locating tabs that fit into the hole.

Pretty well flush on the other side.

Gosh, i can’t recall for sure the butterfly shaft diameter, maybe it was 8 mm, yeah I think so. I do have an 8mm reamer. Anyhow, I did think about bearings instead of bushings. But the bearings I had on hand had a larger OD and that would have meant taking the throttle body to work to use the milling machine; tedious set up and then a boring head.

Assembled. I have to say the action of the butterfly is smooth as silk, much better than the Delrin. Come to think about, I wonder if I reamed the bushings the last time?

The throttle position switch now is easier to set, there is no wobble in the butterfly shaft.

Saw this on the samba, i think it was syncroghia that posted in his thread about adding high top to his 16″ syncro. I thought it was a good idea so i gave it a go on the rear hatch.

It is just water pipe insulation, I think its foam polyethylene, cut to length and wedged into the cavity. Now that summer’s over one might find pool noodles going cheap and I think they would do too.

I like this because it is cheap and fast to install. No gluing and I don’t think it will trap moisture against the metal.

I stuck on a bit of peel and stick roofing stuff to dampen panel noise. My van had some factory applied bits already there. Remember this is a converted 7 passenger tin top. I don’t think we sties have the factory sound proofing in the back hatch, but they do have the dreaded fiberglass batting.

And just because i had some, i pushed in some 3/8″ thick closed cell foam. Left over pipe insulation stuck on lip of cut out.

I liked how it went in, I think I’ll do more of it.

About 2 months and no blog posts, sheesh, the next few posts will be playing catch up.

The 85 model year and newer vanagons have a much improved sliding door. Easier operating and a bit quieter than the old style but I thought it could be even better. I had tried UHMW polyethylene tape on the surfaces that the rollers ran on would be the ticket, blog post about that here. But the tape wore out after a year and a bit.

So i thought about a plastic version of the steel rollers. I made a quick and dirty prototype from some Delrin to try on the middle track (the track under the cover on the side of the van).

Not quite an exact copy and a bit out of focus. Here it is installed.

Verdict? Well it is quieter than the steel roller and it rolls just as easily. But with that track silenced a little, now I could hear the lower track roller noise. So some time later I set about making another middle slider roller and seeing what I could do about the lower track roller.

Middle roller, more care taken. Oh, I should mention that the bearing used in the roller is a 607RS. Dimensions are 19mm OD, 7mm ID, 6 mm thick, and rubber shield.

I took the sliding door right off as I was working on the lower roller at the same time. Here is the stock steel roller.

And my Delrin version installed. See the 2 other bearing above the plastic roller? They run in a vertical channel above the rail the main roller runs on. I didn’t do anything with them, but i probably should have thought about it.

I was going to make a lower track roller from scratch but I found a plastic roller in my junk pile. I think it was from a hanging door, but I can’t remember anything more about it. I wish I did because it is very close to the stock roller dimensions. I just had to reduce the OD by a few millimetres and replace the bearing with a 607RS. It originally had a 6mm ID bearing. The circlip retaining the bearing was a real bear to remove and I accidentally broke a little of the plastic.

here is the stock steel roller. The roller is on a post on the lower assembly , secured by a circlip. The plastic shield can be pried off and the clip removed and the roller pulled from the shaft.

This is not a roller with a pressed in bearing, the bearing and the roller are all one piece.

Has a rubber shield on the inside, the bracket side, face.

Comparison of the stock roller and the hanging door roller. Both have somewhat similar profiles. Close enough for me anyway. But as I mentioned before, I had to turn down the OD of the plastic roller.

Plastic roller with new bearing installed

And showing where I broke the darned thing.

And there it is installed on the door bracket.

So did it make a difference? Yes, it did. Again quieter and smoother. The door still is not as quiet as I would like and I think some of the noise is coming from those vertical bearings on the middle slider, the pair I should have paid more attention to.

You know, this is the kind of project that 99.9% of people would look at and shake their heads, mutter “get a life” and then wander off to chat with someone else. It is only when i sit down and write this post does that realization sink in.

Crikey, forgot to add an important thing… to thank “ZsZ” for posting measured drawings on this Samba thread. I’ll be cheeky and link directly to the drawing.