How to assemble window of MK IV drop head


Good day,
I’m assembling my doors of my DHC, how do I proceed? first bolt both chrome rails and then slide the glass from above? do I have to undo the glass from the bottom rail of the window regulator?
rads Polti

(Rob Reilly) #2

This is from the Mark V Service Manual.


(David) #3

This is the order I did on my 1948 MK IV (which is the saloon not the drop head):

  1. Fit the outer chrome trim to the door with new weather seals.

  1. Leave window glass in bottom rail of window regulator, but assemble other parts of window regulator in side the door.

  1. Slide glass down from above into door cavity and re-engage glass rail into arm of window regulator.

  2. Fit assembled quarter light vent, making sure the window glass travels up the vertical chrome section of the Quarter Light OK.

  1. Grease and make sure everything works smoothly.

I did find that the new rubbers and weather seals I bought did require some bedding in, trimming with a knife, and also time and patience adjusting the screws, etc for good alignment.

  1. Fit internal door panels, handles, and trim.

(Ed Nantes) #4

Firstly to be a wet blanket, the saloon windows do not have any chrome trim on them . They have Bailey channel top and sides. and along the bottom the same channel but flat , not U shaped. The correct channel was available until recently here, It has a woven finish at the edges where it is seen, Although only available in a U section , we just cut it down the centre with tin snips and flat
However the DHC is different, Frankly a Heath Robinson design.

But we are assembling one at present. A LHD car so how the owner is going to drive it in Australia beatsme. There’s little enough rear vision when it’s on the intended side of the road. Any way … the channel on the bottom of the glass. Check that it isn’t corroded, It often is. If so it’s a standard section and used to be available from old car suppliers in UK. Other wise it can be folded up, but no shortcuts with the cross section
The glass was originally held in with glazing rubber. Flat sheet that was soaked in kero, the glass pressed in and the kro expanded the rubber and gripped the glass, Then an hour spent trying to clean one’s hands.

The DHC has chrome pivotted channels fr and rear of the door. Make sure these are in the same plane vertically as the glass won’t twist. And from he side they should be parallel with the screen pillar at the front , and the B pillar when raised. None of this can be assumed

Inserting the glass is easier with 2 people. The winding mech is not attached to the door but loose. The glass is lowered and the floating around arm[s] on the mech are engaged in the channel on the bottom of the glass. [ Pre- greased]] This will involved trying out winding the handle to move the arm.
Then when the glass and channel are engaged move the mech around while winding and put the countersunk mounting screws in . One at a time. Get one in and wind the mech around till another lines up.

The same general principle applies to the saloon windows but the glass is smaller and has only one arm on the winder.

(David) #5

I stand corrected by Ed’s better knowledge than mine. Strange that my 1948 SE car (UK car) had chrome bottom window strips - which I just had re-chromed and refitted, and are a perfect machine pressed shape, etc to fit the door.

(Ed Nantes) #6

Just back from helping Doug assemble the windows in the doors of a Mk IV DhC\ If it’s any help we…
had new glass cut and 'Triplex " etched. Used glazing rubbr to put the slide/ winder strip on the bottom[ Rubber gloves are worthwhile there]
The assembld the winder mach onto the glass. The DHC has 2 arms from the winder mech and these should be at about 10.30 and 1.30 angled to install
The giggle the window/ winder assembly in [ one person] while the other installs the 1/4" C sunk BSF screw that hold the mech to the long bars top and bottom
There are numerous traps , getting one or more of the bars mixed up from side to side.
getting ti t all installed and finding out that under load, the pinion gears jump
The DHC pinion is under much more load than the saloon. so I presume this is why ona low mileage car it had stripped.
Fortunately many other Jags used the same basic mech and the pinion gears from them can be substituted
Probably or preferably from a rear door which should have had less use.