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Alternator Date codes
There are three date codes on most Chrysler round back alternators built between 1960 and 1971. The exception to this is some early '60s units. There was a company called Lester that was casting some housings and they apparently were not required to put a casting date on their castings. When checking your castings, don't use sandpaper or a wire brush. We have found that a toothbrush and some mineral spirits will clean the housing while highlighting the dates. If more cleaning is needed, use a brass brush. The square backs built from model year '72 and up had casting dates but the part number and build date were stamped on a tag that was attached by one of the through bolts.
Round back ('60 thru '71) Square back ('72 and up)Front half casting date
There is a casting date on the front half of the alternator. We call it a date wheel and we have seen many styles but they are all read the same. There is a 2 digit number in the middle and that is the year. There are 12 "pie" sections that can be filled with raised dots. Each pie section is a month and each dot is a week. See examples below for two different styles. The first would be read as an early November 1970 casting and the second would be read as mid January 1966. The third picture shows a Lester. Note that there is no date wheel, but if you enlarge the picture, you will see an oblong circle with the words "Lester" in it. It also has the Chrysler casting number 2095191 cast into it just under the Lester logo. If it doesn't have a Chrysler casting number cast in it, it is an aftermarket housing. We have not come across any Lester castings past 1966.
Click to enlargeRear half casting date
There is a casting date on the rear case half in approximately the same location as the one on the front. It is read the same way as the front. Again, it could be a Lester with no casting date. The Lester rear housings have the "Forward Look" logo cast into them in about the same location as the date wheel would be. Also, like the front, an oblong circle with the word "Lester" in it will be cast into the housing. The casting number 2095192 will also be cast into the housing. See pics below. The first shows the Lester logo and the casting number. You have to look closely to see the casting number. It is down between the fins near the Lester logo. The second shows the "Forward Look" Logo.
Click to enlargePart Number and build date
All round back alternators will have a build date and a part number cast into them. They are located on a boss that is just below the "Bat" terminal. The part number is a 7 digit number and the build date is a pair of numbers usually underneath the part number. It is read as wk yr. For example the picture below is read as part number 2444599 with a build date of the 20th week of 1968. We don't know what the 2 1 2 number means but we suspect it has something to do with shift, line number, etc.
Click to enlargeTips to see if your alternator is restorable and/or is correct for your car.
1. Check all of the above dates. The front casting date should be before the build date.
2. According to the "Experts", the alternator should be built from 3 weeks to 4 months prior to the build date of the car.
3. If the alternator has been rebuilt at some point in it's life, it has probably been shot blasted and will not be restorable to an OE judging level. It can be restored and painted with a paint that closely resembles the as cast color. Most of our customers are OK with this look for their driver type cars but I am told that it is not OK for OE gold type judging.
How to tell if your alternator has been rebuilt.
1. Check the casting dates and make sure they make sense. Most rebuilds will have mismatched front and rear covers.
2. The pulley should be a stamped unit. A lot of rebuilds have machined pulleys, usually dual groove as they will fit everything.
3. Look at the rear bearing. Most rebuilds will have a flat bearing. The original bearings had some raised ridges on them. See pics below. Note that most of our units have a flat bearing because that is all that is available. We do have some NOS bearings available for an extra cost. We prefer to save those for cars that will be OE gold judged as the supply is limited.
Click to enlarge4. Look at the diodes. The original diodes were date coded. You probably won't be able to decipher the dates, but the positive diodes might still have some red still visible and the negatives might have some black legible. If by chance they are legible, the dates are a 4 digit number. The first three are a day and the last is the year. The pics above would be the 98th day of 1969. These should be dated prior to the build date of the alternator.
5. Look at the screws. Up through calendar year 68, the screws had a silver finish. Some time in 69, they switched to a blackened screw. We have seen both screws in the 69 and 70 alternators. It seems like they were using both. For the record, the black screws can be a bear to remove. Be careful as they break easily. The silver coated ones come out easily 95% of the time.
Click to enlargeIf all of the above seem correct and it doesn't look sandblasted, It may be a candidate for an OE level restoration.
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Starter Date codes
There are two date codes on most Chrysler starters built from 1962 up through the eighties. When checking your castings, don't use sandpaper or a wire brush. We have found that a toothbrush and some mineral spirits will clean the housing while highlighting the dates. If more cleaning is needed, use a brass brush. This segment covers the gear reduction starters that make the noise that we all know and love. I will cover the direct drive starters separately. The original gear reduction starter design lasted through the '69 model year as part number 2095150. For the '70 MY the solenoid mounting was changed to provide better sealing. This new design had two through bolts holding the solenoid on and the part number was 2875560. For the '73 MY and up, the part number was changed to 3656575.
Click to enlargeGear housing casting date
There is a casting date on the aluminum gear housing. Most are similar to the alternator date wheels. There is a 2 digit number in the middle and that is the year. There are 12 "pie" sections that can be filled with raised dots. Each pie section is a month and each dot is a week. We have seen a few 64 through 68 castings with a rectangular date code. It is a rectangle with 12 segments that can be filled with raised dots. The year is cast below the rectangular box. See examples below . The first would be read as an August 1969 casting and the second would be read as mid July 1964.
Click to enlargePart Number and build date (???)
All Chrysler starters will have a build date and a part number cast into the Armature housing. They are normally located near the end of the starter. Every once in a while we see one stamped on the end of the housing that is closer to the gear housing. The part number is a 7 digit number and the build date is a three digit number stamped underneath the part number. It is read as wk yr where the first two digits are the week and the last digit is the year. For example the picture below is read as part number 2875560 with a build date of the 40th week of 1969. It is thought by some that this build date is the build date of the starter. I am not convinced of this. Although most of the time, this date is after the casting date on the gear housing, I have seen enough of them that were dated before the gear housing to make me think that this date is just the build date of the housing itself. In either case, you have to go by the later of the two dates when dating the starter.
Tips to see if your Starter is restorable and/or is correct for your car.
1. Check both of the above dates to see if they make sense.
2. According to the "Experts", the starter should be built from 3 weeks to 4 months prior to the build date of the car.
3. If the starter has been rebuilt at some point in it's life, it has probably been shot blasted and will not be restorable to an OE judging level. It can be restored and painted with a paint that closely resembles the as cast color. Most of our customers are OK with this look for their driver type cars but I am told that it is not OK for OE gold type judging.
How to tell if your starter has been rebuilt.
1. Check the casting dates and part numbers make sure they make sense. Most rebuilds will have mismatched gear housings and armature housings.
2. Check the pole screws on the armature housing. Up through 1968 MY should have slotted screws, '69 thru 72 have flat phillips screws, and the 3656575's have phillips pan head screws.
Click to enlargeIf all of the above seem correct and it doesn't look sandblasted, It may be a candidate for an OE level restoration.
Chuck's Plum Crazy Garage
