Author Topic: Rally Pac Clocks -  (Read 4318 times)

Offline jwc66k

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Rally Pac Clocks -
« on: February 14, 2016, 08:18:50 PM »
One of those "round-tu-its", I got around to it today, some pictures of the typical problem with 60's era Ford, in our case Mustang, clocks. I was asked to try and "fix" a dozen 65-66, and 67-68 clocks. The mechanism is probable the same on 69-73 clocks, I don't know. They go in different places on those cars but the internals are identical. I was successful in repairing all but one (see below).
The theory: when the contacts are closed (pic 1), 12vdc is directed to a solenoid that pulls the moving contact away from the fixed contact. A main spring type action moves some gears that make the arms tell time as it closes. There is an adjustment for the main spring too. When the contacts closes again, about 40 to 50 seconds, it repeats. After 20 years of doing this, the contacts arc over, get pitted and either stick (blows a fuse when this happens) or no longer conduct electricity. In either case the clock don't work (that's how to tell if a Rally pack is an original - the clock don't work). Pic 2 is a close up of pic 1. The lower left contact (LH red arrow) is the movable one. Between the gears and the arrow is the main spring. If it is bouncing around, toss the clock, or save it for somebody with a lot of patience (I don't have much) and watch repair skills to make use of the rest of the clock. Pic 3 is a close up of the fixed contact. It has been burnished (a very fine filing technique) with a burnishing tool. The diameter of the contact is about 0.110 inch. There are still pits in it. Pic 4 is a close up of the moving contact (LH) and the fixed contact (RH). It too has been burnished and there are also remaining pits. But it does work. I figure there's five years of life left.
Another "quirk" of these clocks is if you don't start and run your car for a couple of weeks, they wear the battery down. That's the best reason for a battery disconnect switch I can think of.
I haven't tried this tool I found on Amazon -
http://www.amazon.com/GC-Electronics-Fine-Grade-Burnishing/dp/B00B5OK1AO
- but I will order it and this one too -
http://www.amazon.com/GC-ELECTRONICS-STANDARD-WIDTH-BURNISHING/dp/B00DJS6X9M/ref=pd_bxgy_469_2?ie=UTF8&refRID=1ZYN313MR7C2B4KSCVM7
(they both qualify for free shipping) to see if I can get the contacts in better shape.
Jim
I promise to be politically correct in all my posts to keep the BBBB from vociferating.

Offline preaction

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Re: Rally Pac Clocks -
« Reply #1 on: February 14, 2016, 08:42:36 PM »
It seems there are contacts of this type every where with ford and mercury products I for one would like to see how you make out, thanks Paul.
8F02R218047-  July 18 1968   Dearborn

Offline WT8095

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Re: Rally Pac Clocks -
« Reply #2 on: February 14, 2016, 11:29:56 PM »
Old pinball machines have hundreds of open-frame leaf switches with this type of contact (probably tungsten). The Pinball Resource sells replacement contacts, but they do not have a size listed.

http://www.pbresource.com/pfswitch.htm

Would be a nice challenge to remove and replace the old contacts...


They also sell contact disc grease which lubricates and protects the contacts.

http://www.pbresource.com/tools.html

Electrical contact cleaner works good too, it leaves a slight lubricating film.
Dave Z.

'68 fastback, S-code + C6. Special Paint (Rainbow promotion), DSO 710784. Actual build date 2/7/1968, San Jose.
'69 Cougar convertible, 351W-2V + FMX, Meadowlark Yellow.

Offline jwc66k

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Re: Rally Pac Clocks -
« Reply #3 on: February 15, 2016, 12:18:29 AM »
Would be a nice challenge to remove and replace the old contacts...
These contacts have a rivet-like rolled attachment on the opposite side of the contact surface, looks to be about a 0.037inch hole. A bit to small for "old Shaky" to attempt.
They also sell contact disc grease which lubricates and protects the contacts.
http://www.pbresource.com/tools.html
Electrical contact cleaner works good too, it leaves a slight lubricating film.
I applied a dab of contact grease on the ones I fixed before they went up on e-bay (with no guarantee).
Thanks Dave,
Jim
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Offline 196667Bob

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Re: Rally Pac Clocks -
« Reply #4 on: February 15, 2016, 04:28:30 AM »
I can't tell you how many Ford clocks from the mid fifties up through my 67 Mustang that I have fixed over the last 50 plus years using the same basic procedure as Jim has noted. My "burnishing tool" of choice has always been a piece of 320 wet/dry sandpaper, folded over so that when passed between the points, it "burnishes"  both points. Over the years, I have seen this to be the most common problem causing clocks not to work. I figured this out in the early 60's for my '57 Retractable (wanting everything to work correctly on the car), and when I was showing it during the 80's, other club members couldn't believe that my clock functioned. I resurrected, and saved from the scrap pile, many 57-59 friend's clocks during that period. I finally had to do it again to my 57's clock in the 90's, and probably will again once I get it back on the road again, since it has been sitting for about 8 years now. I have also applied this same fix to my 59 Retractable and Ranchero, my 57 and 62 T-Birds, and my 66 Rallye Pac and 67 clock with successful results. The "fix" doesn't take near as long as the R & R.

Bob
1966 Coupe, C Code, 3 Sp MT, 6T07C154XXX, Build Date 11/22/65
1967 Conv, C Code, C4, 7F03C154XXX, Actual Build Date 01/31/67
MCA 04909

Offline WT8095

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  • Dave Z.
Re: Rally Pac Clocks -
« Reply #5 on: February 15, 2016, 09:06:35 AM »
These contacts have a rivet-like rolled attachment on the opposite side of the contact surface, looks to be about a 0.037inch hole. A bit to small for "old Shaky" to attempt.

Definitely stay away from coffee before giving it a try...  ;)

In your photos the contacts look severely pitted from arcing, not just mechanically worn. Is there any sign of a flyback diode to protect the points? I'm guessing there isn't one. It shouldn't be too hard to add one, but I can't see how accessible the wiring is.
Dave Z.

'68 fastback, S-code + C6. Special Paint (Rainbow promotion), DSO 710784. Actual build date 2/7/1968, San Jose.
'69 Cougar convertible, 351W-2V + FMX, Meadowlark Yellow.

Offline 196667Bob

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Re: Rally Pac Clocks -
« Reply #6 on: February 15, 2016, 11:03:04 AM »
Definitely stay away from coffee before giving it a try...  ;)

 Is there any sign of a flyback diode to protect the points? I'm guessing there isn't one. It shouldn't be too hard to add one, but I can't see how accessible the wiring is.

Dave : This is something I've been thinking about for years; a condenser or diode to reduce the sparking effect on the points. Maybe a good EE (like 67gta289) can help on this.
It's just something that I've never gotten around to asking him about as I've had other items more important to tap into his knowledge and "hands on" experience about. This now seems to  be "timely" (pun intended).

Bob
1966 Coupe, C Code, 3 Sp MT, 6T07C154XXX, Build Date 11/22/65
1967 Conv, C Code, C4, 7F03C154XXX, Actual Build Date 01/31/67
MCA 04909

Offline WT8095

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Re: Rally Pac Clocks -
« Reply #7 on: February 15, 2016, 09:39:19 PM »
I'd start with a diode. I can spec one out if someone (Jim?) can get a measurement of the coil current. Probably have to hold the contacts closed for a few seconds to be able to get an accurate reading. Alternatively, measuring the coil resistance would probably get us close enough to pick a diode.
Dave Z.

'68 fastback, S-code + C6. Special Paint (Rainbow promotion), DSO 710784. Actual build date 2/7/1968, San Jose.
'69 Cougar convertible, 351W-2V + FMX, Meadowlark Yellow.

Offline 67gta289

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Re: Rally Pac Clocks -
« Reply #8 on: February 16, 2016, 07:29:43 AM »
You guys are on the mark - the flyback diode should do the trick.    In addition to the coils specifications (current or resistance) it would be good to know the cycle time of the contact.  If it cycles fast enough we need to be concerned about the diode recovery time.   How often does the contact make or break?  I've never looked at one closely.
John
67 289 GTA Dec 20 1966 San Jose
7R02C156xxx
MCA 74660

Offline WT8095

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Re: Rally Pac Clocks -
« Reply #9 on: February 16, 2016, 08:36:11 AM »
It's been awhile since I've run one, but I remember it being about once a minute or so. When the solenoid fires, it winds the mainspring and then the clock runs mechanically for a period of time. As it winds down, the contacts close to energize the solenoid, and the cycle repeats. Very low duty cycle for the solenoid.
Dave Z.

'68 fastback, S-code + C6. Special Paint (Rainbow promotion), DSO 710784. Actual build date 2/7/1968, San Jose.
'69 Cougar convertible, 351W-2V + FMX, Meadowlark Yellow.

Offline midlife

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Re: Rally Pac Clocks -
« Reply #10 on: February 16, 2016, 01:39:33 PM »
All very interesting.  But what I would really like to know is whether you can turn the clock back....



...say 25 years earlier so I wouldn't have gray hair and 50 pound lighter... ;D
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Offline jwc66k

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Re: Rally Pac Clocks -
« Reply #11 on: February 16, 2016, 01:52:59 PM »
I'd start with a diode. I can spec one out if someone (Jim?) can get a measurement of the coil current. Probably have to hold the contacts closed for a few seconds to be able to get an accurate reading. Alternatively, measuring the coil resistance would probably get us close enough to pick a diode.
Coil resistance is around 11 ohms. The fixed contact is "hot" and appears to go thru the coil. The arm for the fixed contact is steel as it the moving arm and the entire electrical portion is "staked" for assembly. I assume that the moving contact is grounded possibly thru the pivot arm. I would think that anything attached to the moving arm would throw off the movement. Case ground is from a spring like arm at the positive stud/nut terminal. There does not appear any copper in the circuit path that a diode could be attached (in an easy manner). The only visible copper is from the opposite side of the positive stud to the solenoid, the wrong side of the circuit..
How often does the contact make or break? 
The cycle time is 40 to 50 seconds. That comes out to 12 to 15 million cycles in a 20 year period of time. And you wonder why the contacts burn out.
Jim
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Offline jwc66k

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Re: Rally Pac Clocks -
« Reply #12 on: February 16, 2016, 03:34:14 PM »
All very interesting.  But what I would really like to know is whether you can turn the clock back....



...say 25 years earlier so I wouldn't have gray hair and 50 pound lighter... ;D
Not far enough back. Where's a DeLorean when you need one?
Jim
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Offline jwc66k

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Re: Rally Pac Clocks -
« Reply #13 on: February 18, 2016, 02:49:07 PM »
My ohm meter was off. The "zero" at that scale was 1.4 ohms. A different meter gave me a reading of around 2.8 ohms. The "bad" meter is history.
Jim
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Offline jwc66k

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Re: Rally Pac Clocks -
« Reply #14 on: May 20, 2016, 05:39:44 PM »
I finally got around to using my new burnishing tool, it works fine. From Amazon -
http://www.amazon.com/GC-ELECTRONICS-STANDARD-WIDTH-BURNISHING/dp/B00DJS6X9M/ref=pd_bxgy_469_2?ie=UTF8&refRID=1FFPVW1KH5DSF4DNB1FM
This burnishing tool will also work on the brush contact areas on motors, as in heater blower and/or A/C fan motors. 
Jim
I promise to be politically correct in all my posts to keep the BBBB from vociferating.