Manual top adjustments?

[William Miller]

Anybody out there have a manual on adjusting tops on early cabs?

I am finishing up my restoration and need to do some tweeking to get it sorted out. The canvas is in great shape and I have all new seals.

I'm thinking there must be a procedure or at least a description of the order to make the adjustments. This I believe also includes adjusting the windows as well because they are part of the deal.


Here is a list of the adjustments I can recall:

1. The main hinge can be moved foreward and back where it attaches at the top of the door jamb. There were also 1 or 2 plastic shims under the hinge.

2. Behind the hinge there is an adjustment for the band that goes arround the bottom edge of the top (I think this tensions the top).

3. There are 3 clamps that secure that band to the rear deck inside the car and below the rear deck carpet. (these are slotted holes in the brackets.

4. There are 2 arms that have a turnbuckle arrangement.

5. There is an adjustment where these arms attach near the seat belt reel. (I think 4&5 some how adjust how the front edge aligns with the windsheild frame)

6. There are some slots in the horizontal frame (running front to back above the horizontal window seals)

7. I recall some type of tension mechanism within those frame sections as well.

8. Pins that go into the windshield frame are adjustable.

6. Verticle window seals (Back of the windows can adjust in and out)

7. Horizontal window seals (Above windows can adjust in and out)

8. Window frame can be adjusted so the top of the window can lean in or out.

9. Stops on the window regulator can adjust the height of the window when fully raised.

10. Stops on the window regulator can adjust the height of the window when it is all the way down (I think) On of my windows goes farther down than the other.

Thats what I can think of. Maybe missed a few.

I generally understand the purpose for most except #'s 4&5.
I'd really like to know the purpose for them all and the correct order in which to make the adjustments.

I think this is probably the secret to getting the top to fit and leak the least amount as possible.

I've seen a manual for a later electric top, but that didn't really go into this detail. It was mostly about replacing the skin.

Any help would be appreciated!

[widebody911]

You've done a good job detailing what's adjustable, but adjusting a cab top is a black art. I posted a small, simple how-to a while back, which just covered the basic top adjustments.

[William Miller]

Thanks, I also saw the conversion manual. I'm going to read that when I can and see what ino is there.

From the search I found that you have not discovered yet what exactly #4&5 are designed for. I do know the turnbuckle does effect the front edge, but would like to know what the other one is for to. I'm sure there is a system. If we find the system the black art will be discovered.

[widebody911]

Originally posted by William Miller
From the search I found that you have not discovered yet what exactly #4&5 are designed for.

The turnbuckle adjusts the angle of the B pillar relative to the roof, which has the side effect of lengthening or shortening the 'reach' of the cab top, and the postion of the window seals relative to the window. When I got my cab top, the guys who packaged it had unwound the turnbuckles, so I had to do some experimentation to get it to work, and I don't think I ever really got it right.

When you go to do your adjustments: do it with the car on level ground; make sure your tires are inflated properly; make sure the top is warm; take measurements and notes; make small adjustments, and then note their effect througout the top's operation range. Budget a good chunk of time for this - don't start on it just before you're supposed to go out on a big date.

Adjusting a cab top is an excercise in the "Peking Butterfly" effect.

[johndglynn]

Bill,

You also have cam adjustment on the intermediate roof bow to correct the outside profile and adjustment on the retaining pins on the B-post pillars so the front roof frame is held down positively when folded back.

Adjusting the roof (from the factory Cab manual):

Height: The roof has to be adjusted for height in relation to the door windows. It's height adjustable by way of shims under the mounting bolts on the B-pillars, one 2mm shim is considered normal, you can either remove or add one more 2mm shim without influencing the kinematics of the frame.

Forward adjustment: This is done using the adjustable struts of the left and right connecting levers (that turnbuckle you mention).

Alignment of the door window with the frame is important. If necessary, align door frame and window with top frame.

Top locks: If preload of the top locks has to be increased, this is done by installing shims.

Correcting stretch of rear window: This requires loosening the three mounting screws of the tensioning bar (bottom of window). Now the rear window stretch can be corrected on the left and right tensioning locks after removing the covers (these are to the rear of the hinges on both sides).

You can then adjust the seals, side seal and top seal.

Took my top to pieces last week making some adjustments. The two straps under the top were old and dried out - replacements available but £42 (about $80) each! Sod that, will have them made for a fraction of that cost.

Worst thing was found a huge crack in the cast side frame behind the passengers' side window. Right through the frame. Can probably be welded as the casting looks like really good quality but still not a cheap fix as it will all have to come apart.

[SCWDP911]

This is a cool thread for cab owners. Can somone elaborate a little more about the window stretch discussed above in John Glynn's comments. Any pictures about the area he is discussing (the tensioning locks?)