BMW used two totally different clock designs on the Tii.  The sooner mannequin (used up till 1973) is the Kienzel clock, which is electromechanical.  It makes use of a mechanical clock mechanism with is wound electrically.  These clocks are often fairly straightforward to repair once they cease working.  The opposite sort of clock (utilized in 1974 and up), is a purely digital clock, with a circuit board, transistors, resistors, and many others.  Any considered one of these parts could cause these clocks to fail, and I’ve not discovered a restore.  My resolution was to swap a VDO clock into the case of the Tii clock.  It retains the unique wiring harness, case and clock face, making it look completely inventory from the surface, whereas reaching reliability.

The donor VDO clock will be obtained from an E12 5-series or E24 6-series BMW or from a 240 sequence Volvo.  The clock face makes use of the identical mounting holes, so you need to use the unique Tii face.  The VDO motion has totally different wiring and case mounting structure, so some modifications must be made to the unique case.  Additionally, the Tii clock is about 60mm in diameter and the VDO clock is about 52mm.  This is not going to mater, because the clock actions are about the identical dimension.

Let’s dive into it…

1)      Acquire your substitute clock.  The 2 choices that I discovered work are a Volvo 240 from the 80’s or a BMW E12 5-series or E24 6-series from the late 70’s and early 80’s.  When you obtain your clock, join it to a 12v energy provide or automotive battery and run it for at the very least 12 hours to ensure it’s working correctly.  Listed below are a few pics of the 2 choices:

2)      Dismantle the VDO Clock
 

     a)      Utilizing a small flat blade screwdriver, I gently began to pry the again lip of the bezel away from the case. I began with a really small screwdriver as getting it began was somewhat harder.  After getting it began, I moved to somewhat bigger screwdriver to attenuate the marring of the bezel.  You’ll not be re-using the Volvo bezel, so no must be tremendous carful right here.  As soon as I had the sting of the bezel pried away, I used to be be capable of pull all of it the best way off.

     b)      As soon as the bezel was eliminated, I used to be in a position to take away the crystal (the clear plastic cowl with the adjustment knob coming via it) and its holder. 

     c)       On the again of the clock there are 2 small screws that must be eliminated.  They maintain the clock motion within the case.  Take away these screws.
 

     d)      The bottom then wanted to be unsoldered from the case.  With a soldering iron, warmth up the solder holding the bottom pin to the case in the midst of the brass circle. This could launch the motion from the clock case.

     e)      On the entrance of the clock motion, I eliminated the fingers by gently prying up on the fingers, evenly from the perimeters.  They need to come off straight up.

     f)       Take away the clock face by eradicating the 2 screws.  In case your VDO clock has it, you may take away the rear foam padding.

     g)      You now have the fully stripped VDO motion.

3)      Dismantle the Tii Clock – This half I wanted to watch out with, particularly eradicating the black bezel that surrounds the face on the outside.
 

     a)      I eliminated the bezel from the Tii clock, principally following the identical course of as with the VDO clock.  Nonetheless, you will want to be extra cautious since you’re re-using the bezel.  As soon as I began prying the bezel, as an alternative of utilizing a twisting movement with the screwdriver, I began prying immediately from the case.  This helped to attenuate the injury to the bezel.  Bear in mind, the ’74 Tii has a big plastic shroud the covers the clock.  This may disguise most flaws to the facet and rear of the bezel.  I additionally did some touch-up after I was completed to assist decrease what’s seen from the entrance.  As soon as I had the sting of the bezel pried away, I used to be be capable of pull all of it the best way off.
 

     b)      I eliminated the crystal and its holder. 

     c)       On the again of the clock there are 3 small nuts that must be eliminated.  They maintain the clock motion within the case in addition to the bottom connection on the again of the case.  I eliminated the nuts after which eliminated the motion from the case.  I saved the bottom wire spade connector, since I used to be going to make use of it later.  I used to be then in a position to take away the motion from the case.
 

     d)      I then eliminated the fingers and face, simply as above with the VDO clock.
 

     e)      You now have the clock case, face, bezel and crystal from the Tii clock.

Listed below are the 2 actions, side-by-side:

4)      Subsequent, I connected the Tii cross-hair face to the VDO motion, utilizing the screws from the Tii clock face.  Then I connected the white Tii fingers, ensuring to put in the hour hand first, then the minute hand.  Set up them each at 12 o’clock straight up.

5)      With every little thing dismantled, I made a template of the mounting and wiring holes so I might modify the Tii case.  I used a skinny, however stiff cardboard, like from a USPS Precedence Mail envelope.  I needed to commute between the Tii case and the VDO case to ensure every little thing lined up and marked it on the cardboard.  I then used a everlasting marker to mark the outlet and slot on the again of the case.  Connected beneath is a PDF of what I used.  It was shut, however nonetheless required some minor modifications to ensure every little thing match excellent.

6)      I used a mixture of a small drill bit, Dremel and a file to drill the additional mounting gap and the opening for the constructive wire connection. The second mounting gap lined up excellent with the prevailing gap on the Tii case that’s marked “+ -”.
 

7)      I cleaned up the crystal, its holder and the bezel (this would possibly require a light-weight coat of spray paint to make it look good once more).
 

😎    I used some JB Weld to put in the sunshine reflector into the case, centering it over its authentic mounting holes.

9)      I bought a few #6 x ¼” x 1/8” spacers from Dwelling Depot. Everbilt sku quantity 398491.  These will house the motion out the right distance from the within of the case.  I used somewhat super-glue to connect these to the highest of the treaded screw posts on the again of the motion.

10)   I then bent the bottom put up towards the screw put up.  I then acquired a really small ring put up terminal and soldered it to the bottom put up in order that the ring was proper over the screw put up.  I additionally glue a really skinny washer over the opposite spacer on the opposite screw put up, with a purpose to maintain the 2 posts equal.

11)   Subsequent, I used somewhat warmth shrink tubing on the underside a part of the 12v constructive spade connector on the again of the motion.  Depart sufficient room for the wiring connector.  This may defend the connector from by accident shoring on the case.

12)   Insert the motion into the case and use the screws from the VDO case to connect the motion.  You’ll need to evaluate how every little thing suits.  To ensure that the time adjustment knob to work correctly, and for the clock to look appropriate within the case, I had to ensure the clock was centered within the case.  This required so adjustment to the mounting screw holes and grinding down of the opposite 2 plastic posts on the motion.  Bear in mind to put in the spade connector for the bottom wire below the screw.

13)   As soon as every little thing suits and is lined up appropriately, I put in the crystal and its holder.  Ensure the time adjustment screw works easily, in any other case some extra adjustment could be wanted.
 

14)   I then put in the bezel over the crystal and the case.  I fastidiously used a bigger screwdriver to press the lip of the bezel again over the lip of the case.  As soon as executed, I touched up the paint on the bezel.

15)   I then completed up by putting in the clock again within the black shroud.

Obtain the case template right here:

Case Template.pdf