Giubo end of Vanagon syncro propshaft

I played around with a spare propshaft that I got the other day (thanks again SImon). I installed it in the van as is and it did have a vibration at around 50 kph. Wasn’t a huge vibration, but it wasn’t acceptable. Believe it or not, but it felt like the vibration was to the rear rather than the front. I took the shaft out and set about taking the giubo end apart. First thing noticeable was the U-joint had slight axial play in one of the crosses. I took off the circlips at that joint and they measure approx 0.050 in thickness. I installed a pair of 0.060 circlips and that eliminated the play. The ears of the joint look a little beaten. Also, doesn’t look like the circlip is fully in the groove does it? But it is… I think 🙂

I still could detect play at that end and guessed it might be from wear in the internal shaft and bushings. So the giubo and end u-joint had to come off.

First, here is a pic of the end of the shaft.

If you look closely you can see the head of a bolt in the inside face of the U-joint. This is to plug a grease nipple port and indicates the joint is not stock. Close up of that area.

Before taking things apart, I sprayed some paint on the works so I could put it all back together in the same orientation.

Then off with the bolts that hold the giubo to the propshaft. The giubo and joint pull out. The shaft doesn’t look too bad on the end.

Then remove the bots holding the giubo to the joint.

That end doesn’t look too bad either. You can see the shaft is thicker in the two spots, that’s where it rides on the internal bronze bushings in the prop shaft. Have a look in the hole in the propshaft. There’s an o-ring in a groove at the end. My other propshaft had the o-ring in a rebate, not a groove.

Now the giubo, sitting roughly in place, and it had washers on either side. Pretty cruddy washers, and my other propshaft did not have them.

With the giubo removed from the joint, I reinserted the shaft into the hole and tried it out for size. It felt pretty good, no slop. So where did that looseness come from that I felt when it was all assembled?

I decided to lube it all up and put it back together. I used a band clamp to squeeze the giubo into shape to let me get the bolts back in to attach joint to rubber.

And same technique when attaching assembly to propshaft.

Well, all assembled (minus those washers) and it feels nice and tight. No play like before. So I put it back into the van and had a test drive. It still has some vibration (again around 50 kph) but it is less. I had to say that didn’t I? Honestly it is better but not what I want. So the shaft is coming off again and I’ll take it to the driveline shop for spin balancing.

Addendum: In the comments Rob advised replacing that U-joint. I agree and I should have mentioned this in the post. I’ll ask the driveline guy to do it this time.

More addendum: Diagram of the end of shaft. Does it look to you like of some sort of cap at the end of the internal tube or is it integral to the inner bushing? I’m thinking the former is the case. Also note that it is a nut and bolt that holds the giubo to the U-joint yoke. In the propshaft above its a bolt, with the propshaft yoke having threaded holes. My other propshaft has same attachment method shown in diagram. No washers between giubo and shaft shown on diagram either. I bet there were some minor changes made to the shaft during production.