Rear shocks

[Erich]

Hi All,

My son and I returned from the 90th Anniversary week and I can proudly say he is now a prewar convert! We have been working on finishing my Ulster Rep. A few things have cropped up. One concerns the rear shocks. The chassis is a short wheel base one, but with the rear axle changed to the wider later one. It was done fairly well. But the shocks are a bit of a dog's dinner. As they came, there were no brass disks and only one spring cup which was on the nut side with the raised portion facing outward. The nut was a nylock. According to Woodrow, there should be two spring cups, with the raised portions facing into the spring, I presume to help locate it. However, when I reversed the one existing spring cup, the ID of the spring was too small to accept the raised portion of the spring cup. So, it appears that I have springs with too small an ID to accept the raised portion of the spring cup. These could be aftermarket springs that are stiffer as the car was once raced, hence the mods with the semi girling brakes, wider rear axle, boxed chassis, etc.

Should I reassemble with the one spring cup reversed as it apparently once worked well, or get new springs and spring cups and assemble as stock. Another question is how much tension on the spring? We've set both at 15 psi.

Erich in Seattle

[Howard Wright]

Hi Erich

I’ve just rebuilt the dampers on my 28 van.  Fortunately I had all the cups and springs but needed new bushes and friction discs.

I found that the springs were too weak to get the friction needed and added an old valve spring inside them.  If you have a Nyloc holding the spring then the thread on the pin is knackered as it should be a fine cycle thread. (I doubt you can get Nylocs in this thread size).

When all back together I checked the force needed to move the damper arm by pushing it up with a set of bathroom scales underneath.  I’ve set mine at 12 lb (not psi??)

Hope this helps?

Howard

[Chris Garner]

Erich. There is only one spring cup but two spring plates which sit either side of the shock absorber arm. The plates are dished and fit / located against the outer contour of the arm. As Howard infers I'm not sure how it was possible to fit a Nyloc to an existing centre bolt. I wonder if the bolt is a made up one with either a BSF or BSW thread at the end. (?)