Friday 25 September 2020

Fettling The Replacement Outer Sill Panels

When you use replacement parts, It's probably wise to assume that some fettling will be needed to make them fit and function as intended. On a whim, I decided to do a test fit of the pins that hold the door springs and spring mechanism in the new sills.
Old and new compared. Spot the difference?
I'm so glad I did because..... the pins didn't fit. They were too tight. I'm glad I didn't find that out after I'd welded the sills in place, as it would have been awkward to access that area.
A cradle and pin in situ under the sill
In fact it wasn't even easy to rectify with the panels still off the car. The shaped edge of the sill panel also meant that I couldn't easily get a file in the holes to make them a little bigger. In the end, I put a pin on my tower drill, spun it and used emery cloth to very slightly reduce it's diameter so that it fitted. 

But it got worse. Fitting the pin showed that the cradles that the pins sit in were too wide. This is quite significant as the cradle has grooves for the springs and for retaining circles, and shoulders the rest in the cradle.
Citroen sill and cradle: aligned to the pin shoulders
On the new parts, the cradle arms aligned to the grooves  - rather than the shoulders - and so might dislodge a circle-or door spring when in use.
The cradle is wrongly aligned to the grooves
I tried bending the two sides of the cradle together, but with the sides no longer parallel, the pin wouldn't fit again! Luckily I hadn't thrown away the old sill panels I had removed and, given these two problems, decided to salvage the original cradles and re-use those. On the old Citroen parts, I carefully drilled the spot welds out from the panel side, making sure I did not cut the cradles. And I carefully drilled out the spot welds from the cradles of the new panels - making sure i did not cut the panel beneath.
Removing the cradles
I compared cradles. The ones from the reproduction panel were so over-sized (wide) that the Citroen cradles could nestle within them! They would have taken some significant re-shaping to reduce the gap and still have the two sides parallel.
The reproduction cradles were over-sized
The spot and drill marks of old and new panels showed me where the donor cradles needed to go and they were soon welded back on to the new panels. 
Telltale marks aided the re-fitting
A test fit of the pins showed every thing was as it should be....I gave the repair areas a basic wash in thinned zinc oxide primer just to prevent fish-rusting and in the expectation that it would wick between the cradle and the panel.