Hitman's Pontiac Trans Am Forum

Trans Am Information => Restoration => Topic started by: Gold78Spc on May 23, 2007, 09:04:55 PM

Title: How I fixed my clock.
Post by: Gold78Spc on May 23, 2007, 09:04:55 PM
I decided to attempt to fix my clock and actually did it so I decided to post what I did here and maybe I can save some of you the money that it costs to send yours out to have it done.  Its actually more work getting the clock out and putting it back in than getting it going.

The clock is actually about 95% mechanical and 5% electric and believe it or not the problem is most likely in the electric.

1. Remove your  under column trim piece and your dash bezel.

2. Hold the knob that you set the time with with one hand and using a very small screwdriver remove the screw from the knob and remove the knob.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0067.jpg)

3. Remove the screws holding in the speedo guage cluster, pull the cluster out and disconnect the tach wires, speedo wires, and speedo cable etc and gently remove the guage cluster.

4. Remove the plastic face from the cluster and the black trim piece.

5. Remove the Lights from the backside of the cluster.  I only took the stuff off of the tach side of the cluster but if you didn't want to chance damaging your printed circuit you could remove all of the lights and screws and take the circuit out.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0066.jpg)

6. Remove the screws and 2 nuts circled in purple.  Then the yellow ones.  The 3 circled in yellow are the 3 main ones holding in the tach.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0065.jpg)

7. Gently lift up on the printed circuit and pull the tach patially out.  It will not come out from the backside, you just need to lift it out far enough to disconnect the red and black wires for the clock.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0064.jpg)

8. After wires are disconnected gently lower tach back into cluster, turn cluster over and remove the tach from the front.

9. When the tach is out turn it over and remove the 2 screws holding in the clock.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0063.jpg)

10. Once the clock is out gently remove the second hand by pulling straight out.  I recommend using your fingernails if you can.  The paint on the face of the second hand is very delicate.  I pulled a little of the paint off using needlenose pliers and ended up having to repaint the face when I put it back together.  Once the second hand is off you can use needlenoses to pull off the minute then hour hand by pulling straight back.  Once the needles are off use a small screw driver to slightly bend out the 3 tabs holding the clock face on.  Only bend them just enough to remove the clock face.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0061.jpg)

11.  Once the clock face is off turn the unit over and again gently bend out the 3 tabs enough to seperate the clock housing.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0059.jpg)

12.  Once the unit is apart you can do quite a few things.  First drop a little 3 n 1 oil on the gears. Then you can test to see if the clock functions mechanically.  Do this by using your finger to move the contact indicated by the right arrow all the way to the right.  This will load the spring and if the unit is mechanically ok your clock will start to work !!.  If your clock is mechanically ok take a little fine grit sandpaper or something similar to clean the contacts up ( indicated by the two yellow arrows).  This is all you really need to do.  You can test the unit by hooking it up to your battery using jumper wires ( Black wire to the body, red to positive cable).  Once the unit has power to it what will happen is when the spring tension pulls the 2 contacts together and electrical charge will throw the right contact all the way to the right and the spring takes over again.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0057.jpg)

13.  Reassembly is basically everything you did in reverse.  When you put the housing back together, and reinstall the face make sure you use needle noses or a screwdriver to pinch the tabs back closed tightly.

14. When you reinstall the hands set the time to 12:00 exactly. Just makes sure your hands will point to the right time when you put it all back together. 

And thats about it.  If I think of any steps I missed or other helpful tips I will make sure I add them.  If anyone has any questions just PM me.  I usually check the forum at least once a day. every other at the most.
Title: Re: How I fixed my clock.
Post by: Gold78Spc on May 23, 2007, 09:16:46 PM
Well thats par for the course for this type of clock but so far its only lost about 1 minute in 9 hours.  So if thats the case I can adjust the time every now and then.
Title: Re: How I fixed my clock.
Post by: Gold78Spc on May 23, 2007, 09:28:13 PM
I actually just tested it 4 times against a digital stopwatch.  It was .22, .50, .12, and .28 seconds behind for a 1 minute test.  Some of that error could be when I hit the button, so over all I think its pretty darn close and as good as you can expect from this clock.
Title: Re: How I fixed my clock.
Post by: Hitman on May 23, 2007, 10:08:05 PM
Nice tip to have.  Thanks for posting it.
Title: Re: How I fixed my clock.
Post by: wheels78ta on May 23, 2007, 10:11:52 PM
Excellent How-To on the clock, Brian...a lot of effort just to get it on here....but why do these clocks not keep good time?  Is there anything that can be done to help it keep better time?    :P
Title: Re: How I fixed my clock.
Post by: ta78w72 on May 23, 2007, 10:52:51 PM
Read the service manual.  There's a disclaimer about how hard it is to make a clock accurate.  Kind of funny.

"The electric clock, available on all series, operates on direct current from the car battery and must not be compared too closely for accruacy to a home electric clock operating on alternating current.  The cycles per second of alternating current used in the home are controlled and periodically correct at the power house, thereby elimating accumulation of errors.  With the direct current system, no such control is possible; therfore, automobile electirc clocks will accumulate errors day by day the same as handwound, spring-operated clocks."

The most common problem with these clocks is not electrical, it's that the clock needs oiling.  The second most common problem, which can be fatal, is pitting of the contacts.  Sometimes you can file them, but most of the time it's curtains.
Title: Re: How I fixed my clock.
Post by: eroc022 on May 24, 2007, 11:43:52 AM
thats a good writeup.....but you could always just buy another car with a working clock right ?
Title: Re: How I fixed my clock.
Post by: Gold78Spc on May 24, 2007, 01:17:59 PM
It might be easier !!
Title: Re: How I fixed my clock.
Post by: rkellerjr on May 24, 2007, 01:41:05 PM
Brian, that is an awesome write up guy!  Thanks for posting.
Title: Re: How I fixed my clock.
Post by: Teglhus on June 14, 2007, 05:51:42 PM
My clock in the TA will only run for 10-20 sec. then it will stop. That can only be oil job, and the thing should run again right? :)
Title: Re: How I fixed my clock.
Post by: 784mula on July 06, 2007, 10:45:36 PM
My clock is also spuratic where it will run for several minutes, then stop or when it feels like it. I may try this procedure when I get some time. Thanks for the post.
Title: Re: How I fixed my clock.
Post by: 77 se ta on July 06, 2007, 11:19:05 PM
On mine, once I start the car I pull out the adjusting knob and release it, then the clock will run accurately as long as the car is running... shut off the car, the clock stops running within a couple minutes

So I get in the car, start it, set the time, release the knob and I'm good... weird I know, but that's how mine works
Title: Re: How I fixed my clock.
Post by: willie g on July 24, 2007, 07:38:58 AM
The clock in my 80 ta (in my avatar) keeps perfect time but the tach doesn't work.Can't have it all can we? ;)
Title: Re: How I fixed my clock.
Post by: Keith on December 16, 2007, 12:46:18 AM
Wow, what can I say. That was awesome.

Thanks!

I decided to attempt to fix my clock and actually did it so I decided to post what I did here and maybe I can save some of you the money that it costs to send yours out to have it done.  Its actually more work getting the clock out and putting it back in than getting it going.

The clock is actually about 95% mechanical and 5% electric and believe it or not the problem is most likely in the electric.

1. Remove your  under column trim piece and your dash bezel.

2. Hold the knob that you set the time with with one hand and using a very small screwdriver remove the screw from the knob and remove the knob.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0067.jpg)

3. Remove the screws holding in the speedo guage cluster, pull the cluster out and disconnect the tach wires, speedo wires, and speedo cable etc and gently remove the guage cluster.

4. Remove the plastic face from the cluster and the black trim piece.

5. Remove the Lights from the backside of the cluster.  I only took the stuff off of the tach side of the cluster but if you didn't want to chance damaging your printed circuit you could remove all of the lights and screws and take the circuit out.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0066.jpg)

6. Remove the screws and 2 nuts circled in purple.  Then the yellow ones.  The 3 circled in yellow are the 3 main ones holding in the tach.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0065.jpg)

7. Gently lift up on the printed circuit and pull the tach patially out.  It will not come out from the backside, you just need to lift it out far enough to disconnect the red and black wires for the clock.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0064.jpg)

8. After wires are disconnected gently lower tach back into cluster, turn cluster over and remove the tach from the front.

9. When the tach is out turn it over and remove the 2 screws holding in the clock.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0063.jpg)

10. Once the clock is out gently remove the second hand by pulling straight out.  I recommend using your fingernails if you can.  The paint on the face of the second hand is very delicate.  I pulled a little of the paint off using needlenose pliers and ended up having to repaint the face when I put it back together.  Once the second hand is off you can use needlenoses to pull off the minute then hour hand by pulling straight back.  Once the needles are off use a small screw driver to slightly bend out the 3 tabs holding the clock face on.  Only bend them just enough to remove the clock face.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0061.jpg)

11.  Once the clock face is off turn the unit over and again gently bend out the 3 tabs enough to seperate the clock housing.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0059.jpg)

12.  Once the unit is apart you can do quite a few things.  First drop a little 3 n 1 oil on the gears. Then you can test to see if the clock functions mechanically.  Do this by using your finger to move the contact indicated by the right arrow all the way to the right.  This will load the spring and if the unit is mechanically ok your clock will start to work !!.  If your clock is mechanically ok take a little fine grit sandpaper or something similar to clean the contacts up ( indicated by the two yellow arrows).  This is all you really need to do.  You can test the unit by hooking it up to your battery using jumper wires ( Black wire to the body, red to positive cable).  Once the unit has power to it what will happen is when the spring tension pulls the 2 contacts together and electrical charge will throw the right contact all the way to the right and the spring takes over again.

(http://i80.photobucket.com/albums/j195/sdragon555/Img_0057.jpg)

13.  Reassembly is basically everything you did in reverse.  When you put the housing back together, and reinstall the face make sure you use needle noses or a screwdriver to pinch the tabs back closed tightly.

14. When you reinstall the hands set the time to 12:00 exactly. Just makes sure your hands will point to the right time when you put it all back together. 

And thats about it.  If I think of any steps I missed or other helpful tips I will make sure I add them.  If anyone has any questions just PM me.  I usually check the forum at least once a day. every other at the most.

Title: Re: How I fixed my clock.
Post by: MacGyver on December 16, 2007, 01:24:45 AM
Great write up man!  Makes me wish I had a 2nd gen to try this with!  LOL
Title: Re: How I fixed my clock.
Post by: pwrcat4000 on November 08, 2011, 05:38:14 AM
Now how do you adjust it so it keep time well or at least better any takers
Title: Re: How I fixed my clock.
Post by: Grand73Am on November 08, 2011, 07:34:51 PM
Yes, very helpful writeup. Funny thing about that type of electric/windup clock is that they used that same type of mechanism at least as far back as 1955, so it's quite an antique design.

The 79-81's have quartz clocks, which are much more dependable and accurate. The original one in my 79 still keeps great time.
If you decide to take your cluster out,  it might be worth seeing if a 79-81 quartz will swap into your earlier cluster. Of course, you'd have to find a working 79-81 quartz clock, probably by buying a used cluster. Or some of the clock and instrument repair services may be able to do a quartz conversion on your old clock.
Title: Re: How I fixed my clock.
Post by: 78ta on November 08, 2011, 10:29:41 PM
As Grand73am mentioned, this design has been around a long time. The clock in my 70 442 is the same.

People have asked if the clock can be adjusted and, if so, how. Here's a couple pics. One from my 70 442 owners manual and one from the 78 pontiac chassis service manual. It's funny, the info regarding the TA is literally the next paragraph after what  ta78w72 posted regarding the disclaimer.
If I were to go to all the trouble to take mine apart to service it, I would hose it down with an electrical contact cleaner or at the very least plain alcohol. Something to break down the old gummy oil and dust that is in the bearings/moving parts. Then oil is with a light machine oil like 3in1. That said, I did this on my 442 and it worked for maybe a few weeks.
Some have mentioned the quartz conversion. I know they are available for the 68-72 Cutlass, Lemans, Chevelle etc so I would think there is a kit for the 78's too. The quartz 79 TA clock sounds like a great idea. Anybody personally done that?
(http://i267.photobucket.com/albums/ii295/w70442/78TA/misc/clocks/clockinfo005.jpg)
(http://i267.photobucket.com/albums/ii295/w70442/78TA/misc/clocks/clockinfo011.jpg)
Title: Re: How I fixed my clock.
Post by: pwrcat4000 on November 14, 2011, 11:18:58 AM
Thanks randy that is awesome that you have that.
Title: Re: How I fixed my clock.
Post by: 78ta on November 14, 2011, 11:58:59 PM
Thanks randy that is awesome that you have that.

You're welcome. The only problem with that procedure is that you kinda have to drive the car regularly and adjust it regularly for it to get close and stay close. Close still being a relative term. Unfortunately, most of us only drive our cars a few times a month. Maybe more than that in the summer but definitely less in the winter.
Title: Re: How I fixed my clock.
Post by: pwrcat4000 on November 18, 2011, 02:25:28 AM
I currently have mine plugged in to a power supply


(http://www.motortopia.com/files/cars/album_tacklingthetach/4eb21be0d8f79/Tackling_the_Tach_Nov_2011_001JPG_Thumbnail1.jpg)


I have been moving forward 5 min at a time today it was only off by less than a min after 12 hours
Title: Re: How I fixed my clock.
Post by: skisix38off on December 13, 2011, 08:06:00 AM
I pulled my dash apart a weekend ago to try this fix and was so excited that my clock when I put it back in.  After 3 days of working, it stopped again. The only electrical connection that I didn't clean was the solder joint for the positive terminal on the clock itself.  If it's not that, it's mechanical somewhere in the little gears, I put a little lube on those.  If I pull the adjuster pin out to change the time, the clock will work for a few minutes and then stop again. 

Any suggestions?

Greg
Title: Re: How I fixed my clock.
Post by: 78ta on December 21, 2011, 10:38:29 PM
I pulled my dash apart a weekend ago to try this fix and was so excited that my clock when I put it back in.  After 3 days of working, it stopped again. The only electrical connection that I didn't clean was the solder joint for the positive terminal on the clock itself.  If it's not that, it's mechanical somewhere in the little gears, I put a little lube on those.  If I pull the adjuster pin out to change the time, the clock will work for a few minutes and then stop again. 

Any suggestions?

Greg

If it only works for a couple minutes and stops, it sounds like the throw arm contact might not be making good contact with the solenoid as it comes back to make contact and get thrown again. Lightly file both sides of that contact if you haven't already.
Also, for anyone doing this, I'd recommend spraying some kind of electrical contact cleaner all over the moving gears to remove the grit and debris BEFORE applying the light machine oil to them. If you're just applying oil with out cleaning the gears, you're encapsulating the 40 years worth of crud that is already there causing the gears to bind.
Title: Re: How I fixed my clock.
Post by: hada76 on December 22, 2011, 12:22:16 AM
anyone notice this thread jumped ahead 4yrs w/o missing a beat?
Title: Re: How I fixed my clock.
Post by: skisix38off on January 03, 2012, 04:36:51 PM
I pulled my dash apart a weekend ago to try this fix and was so excited that my clock when I put it back in.  After 3 days of working, it stopped again. The only electrical connection that I didn't clean was the solder joint for the positive terminal on the clock itself.  If it's not that, it's mechanical somewhere in the little gears, I put a little lube on those.  If I pull the adjuster pin out to change the time, the clock will work for a few minutes and then stop again. 

Any suggestions?

Greg

If it only works for a couple minutes and stops, it sounds like the throw arm contact might not be making good contact with the solenoid as it comes back to make contact and get thrown again. Lightly file both sides of that contact if you haven't already.
Also, for anyone doing this, I'd recommend spraying some kind of electrical contact cleaner all over the moving gears to remove the grit and debris BEFORE applying the light machine oil to them. If you're just applying oil with out cleaning the gears, you're encapsulating the 40 years worth of crud that is already there causing the gears to bind.

When I put it all back together the clock worked for 3 days and kept decent time in that period.  Then it stopped working, and I would get it to run again by adjusting the time and it would run ofr a n hour or so and quit...  Does that sound like the throw contact arm?  Where is the throw arm contact?  I don't know what to file.  Thanks for the good suggestion though!
Title: Re: How I fixed my clock.
Post by: ntgarwood on August 03, 2020, 06:46:27 AM
I'm 13 years late to this thread but this was amazing!!! My clock didn't work and I had the gauge cluster out so I gave it a shot. Worked exactly as mentioned and now the clock is functioning!! Thank you so much for this post