Damper stake out
Posted: Sat May 09, 2020 10:53 pm
Lovely drives in the last few days to our customary evening picnic spot at Burpham, near the Sussex Downs. Only trouble is the poor surface of the road to it after the A27, the car rattling most of the way. Yesterday, a mile short of the destination, a distinct hard knock was heard from the left rear wheel as every bump was traversed. At the stop I could make the same knock sound by trying to bounce that corner up and down. Everything was fine apart from the knock and we got home without incident after a walk, a cuckoo (second of the day) and the picnic.
Thinking about what it could be I decided that the damper retaining nut must have unscrewed itself and the damper body was moving up on bumps then falling slowly by gravity until the next bump impacted it. Sure enough, that is what I found but doing the nut up again without stripping the unit out wasn't simple.
The nut, on my unit, is a short tube with an external pipe thread welded to a thick sheet metal hexagon, about 2" (50 mm) AF, with a hole for the damper shaft to pass through it. Although I could turn this nut with my fingers (after lowering the hub to expand the spring) it wouldn't grip the internal thread of the strut's tube. I could feel that the top of the damper was not central in the tube but I couldn't lean the tube over by hand, eventually jacking up the edge of the spring platform to do it. Then the nut engaged and tightened up after about six turns. I tightened it harder with some narrow adjustable pliers before attempting to stake the tube in two places. I assume I missed this important stage in 2018 when I fitted it; it's a Spax.
Tonight we drove the same road for a picnic and the whole car seemed quieter and smoother and we hardly noticed the poor road leading to Burpham!
Thinking about what it could be I decided that the damper retaining nut must have unscrewed itself and the damper body was moving up on bumps then falling slowly by gravity until the next bump impacted it. Sure enough, that is what I found but doing the nut up again without stripping the unit out wasn't simple.
The nut, on my unit, is a short tube with an external pipe thread welded to a thick sheet metal hexagon, about 2" (50 mm) AF, with a hole for the damper shaft to pass through it. Although I could turn this nut with my fingers (after lowering the hub to expand the spring) it wouldn't grip the internal thread of the strut's tube. I could feel that the top of the damper was not central in the tube but I couldn't lean the tube over by hand, eventually jacking up the edge of the spring platform to do it. Then the nut engaged and tightened up after about six turns. I tightened it harder with some narrow adjustable pliers before attempting to stake the tube in two places. I assume I missed this important stage in 2018 when I fitted it; it's a Spax.
Tonight we drove the same road for a picnic and the whole car seemed quieter and smoother and we hardly noticed the poor road leading to Burpham!