- Joined
- Nov 3, 2014
- Messages
- 824
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- 282
I have had a motorhome based on a 2008 Ducato panel van for 3 years. The rear suspension has always creaked loudly over large bumps at low speed, sounding like a braying donkey or the front door of Dracula's castle ! Various attempts to cure it by spraying rubber lubricant etc were unsuccessful.
Anyhow, last week I finally got round to doing something about it. At each side there is a single rear leaf spring with a shackle a few inches long at the back end. I jacked up each side in turn until the weight was just off the rear wheel, then removed the long bolts from the upper and lower bushes. These needed an E24 female Torx socket for the bolt head and a strong 24 mm hexagon socket to undo the nut, they were pretty tight so a long lever was called for.
I found that the design is a bit unusual in that there are rubber bushes pressed into the chassis and the spring eye, with metal inner liners. Into each of these are push fitted a couple of white plastic "top hat" lining bushes, then close fitting metal thick-walled tubes go through these to act as plain bearings. The upper tube is a bit fatter than the lower tube. The long bolts go through the middle of these tubes and hold the shackle plates tight to them. I guess the idea is that the white lining bushes stay put, and the tubes rotate inside them, with side thrust being taken between the inside face of the shackles and the "hat" of the bushes.
I found that the upper metal tubes were clean and still showed shiny plating. The lower tubes however were covered in orange rust, and there was a lot of rust powder in the spring eye bush between the top hats. The inside faces of the shackle plates were also rusty at the lower ends. I cleaned off all the rust with a succession of chipping hammer, wire brush and then emery cloth. The whole lot was then reassembled with graphite grease on the rubbing surfaces and a good layer of Waxoyl around the outer parts. The nuts were torqued back up to 145 Nm (107 lbs-ft).
The result was no more creaking at all - very pleasing.
It seems to me that there is a design fault, in that the spring eye has a narrow slot where the end is turned round. This is at the mercy of water spray from the rear wheels, and the slot allows water and grit to get inside the lower bush. As is so often the case with motorhomes, being left idle for long periods probably exacerbates the rusting. I made sure the slots were filled up with Waxoyl to discourage further water penetration. I am told that the design has now been changed.
Anyhow, last week I finally got round to doing something about it. At each side there is a single rear leaf spring with a shackle a few inches long at the back end. I jacked up each side in turn until the weight was just off the rear wheel, then removed the long bolts from the upper and lower bushes. These needed an E24 female Torx socket for the bolt head and a strong 24 mm hexagon socket to undo the nut, they were pretty tight so a long lever was called for.
I found that the design is a bit unusual in that there are rubber bushes pressed into the chassis and the spring eye, with metal inner liners. Into each of these are push fitted a couple of white plastic "top hat" lining bushes, then close fitting metal thick-walled tubes go through these to act as plain bearings. The upper tube is a bit fatter than the lower tube. The long bolts go through the middle of these tubes and hold the shackle plates tight to them. I guess the idea is that the white lining bushes stay put, and the tubes rotate inside them, with side thrust being taken between the inside face of the shackles and the "hat" of the bushes.
I found that the upper metal tubes were clean and still showed shiny plating. The lower tubes however were covered in orange rust, and there was a lot of rust powder in the spring eye bush between the top hats. The inside faces of the shackle plates were also rusty at the lower ends. I cleaned off all the rust with a succession of chipping hammer, wire brush and then emery cloth. The whole lot was then reassembled with graphite grease on the rubbing surfaces and a good layer of Waxoyl around the outer parts. The nuts were torqued back up to 145 Nm (107 lbs-ft).
The result was no more creaking at all - very pleasing.
It seems to me that there is a design fault, in that the spring eye has a narrow slot where the end is turned round. This is at the mercy of water spray from the rear wheels, and the slot allows water and grit to get inside the lower bush. As is so often the case with motorhomes, being left idle for long periods probably exacerbates the rusting. I made sure the slots were filled up with Waxoyl to discourage further water penetration. I am told that the design has now been changed.
