Z quarter window frame fix | The Z Club of Great Britain
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Z quarter window frame fix

Discussion in 'Rebuilds and restorations' started by Skallywag, Aug 1, 2020.

  1. Skallywag

    Z Club Member

    Not seen this issue raised before so I thought my experience might be helpful to anyone who ends up facing the same problem.
    First off, if you imported your Z from the States chances are you're probably safe, since UK cars are far more likely to succumb to this problem since our climate is a tad wetter.

    The problem is first noticeable when a gap appears between the vertical stainless frame bar and the lower horizontal frame bar on the bottom corner nearest the door frame. I had noticed this for some time but didn't give it much thought; that was until the gap had increased to the point that the window frame on the door started to contact with the quarter window frame. Since I was going to totally strip and rebuild the car I decided I would take the opportunity to investigate this issue further.

    I assumed since the frame was stainless everything connected with the frame would be likewise constructed of the same material. It isn't. After stripping out the rubber seals and glass I discovered that the frame connecting lugs are actually made from standard steel. Thankfully the upper and rear most lugs are positioned high enough for any water that slips past the seals not to cause any corrosion problems. However the the lug closest to the door and the lowest of the three is continually sat in any moisture that ha managed to slip past the seals.
    Unsurprisingly this results in the lug rusting away, causing the joint to expand and thereby interfering with the door window frame.

    The solution is however fairly straightforward. Remove the rusted lug by drilling out the spot welds that held it in place. (In my case the lug was so badly corroded it pulled away with very little effort)
    Source some 16mm x 3mm stainless flat bar and form a replacement lug. For some bizarre reason the 240's bottom lug has one spot weld and a 4mm set-screw holding it to the frame. On subsequent models this was replaced with the far more sensible two screw fixing that allows the frame to be seperated with greater ease.

    Using the original fixing hole as a guide, carefully mark the new screw holes through the frame on to the new stainless lug and drill and tap to take two 4mm mushroom headed set-screws. With the new lug in held in place, tig weld through the old spot weld holes to attach the other end of the lug to the frame. This will ensure no future problems.

    Hope this helps if you do find yourself having to tackle this annoying problem

    See attached photographs thumbnail_IMG_0467.jpg thumbnail_IMG_0466.jpg thumbnail_IMG_0468.jpg thumbnail_IMG_0466.jpg thumbnail_IMG_0468.jpg thumbnail_IMG_0469.jpg
    Dyst, Rushingphil, Huw and 5 others like this.
  2. AliK

    Z Club Member
    Staff Member Moderator

    Great write up!!! Thank you for sharing. Pretty sure many of us will need to do this job.
  3. Mr Tenno

    Mr Tenno
    ZClub Administrator
    Staff Member Moderator

    Agreed - had this happen on mine - was very surprised to see the normal steel bonded to the stainless. Galvanic corrosion would probably cause it to happen over time even without much moisture.
    Dyst and AliK like this.

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