3857584 tail housing date codes

[Ronald L.]

Does anyone know how to read these Muncie Tail housing date codes?

See picture, thanks.

[William C.]

Re: 3857584 tail housing date codes

I'd be thinking it was a mold cavity ID.

[Ronald L.]

Re: 3857584 tail housing date codes

I am thinking these were Ratcheting clocks, month year week?

[Joe L.]

Re: 3857584 tail housing date codes

I am thinking these were Ratcheting clocks, month year week?

Ronald------


I think that one of the circles contains information regarding month and week, but no information as to year. I don't recall just how the month and week information was coded, though. I think it might be that the month is shown by a number in one half of the circle and the week is shown by dots in the other half.

[David L.]

Re: 3857584 tail housing date codes

I agree with Joe. The bellhousings have the same circle type date coding.

[Wayne M.]

Re: 3857584 tail housing date codes

Does anyone know how to read these Muncie Tail housing date codes? ....

Ron --- I agree with most of what others have said, and here's examples, after looking at three "584's" I have handy in my stock.

One of the circles is intended to be the month (numeral, above the line, and week, # of dots in the bottom half of the circle). This is similar to maincase castings, shifter sidecovers, and bellhousings, although the quality of this casting info is worst on the tailhousings, IMO.

I have an original '66 M21 trans P02xx assembly; maincase circle [numeral 1 above the line and 5 dots below]. The tailhousing has a "1" and 4 dots. Sometimes the dots are even OUTSIDE the circle. The second circle may be a design revision record, as Noland discusses in his Vol 2. I see your photo shows a "2". Any dots in the vicinity ? I have two housings with what looks like "GM" above the line, with "2" below on one, and GM and "1" below on another, but totally outside the circle.

[Ronald L.]

Re: 3857584 tail housing date codes

Wayne,

In that photo I think I see one sloppily done dot that would be consistent with worn dies. Look at the amount of flash around these two 'plugs'.

1st week of Feb would be consistent with what I have seen on other tail housings that had more lead time than the main case. On 67's I have seen better definition that does coincide with this.

[Jim C.]

Re: 3857584 tail housing date codes

Just to make sure I get it, the circle with the line across the center has a number on top and dots on the bottom. The number indicates the month and the number of dots indicates the week the part was cast. Right? Is it possible to have some dots inside and outside the bottom half of the circle at the same time? I found the circle on the tail casting of my transmission. Where is the circle located on the main body casting of the transmission? Thanks for the info.

Jim C.

[Joe L.]

Re: 3857584 tail housing date codes

Just to make sure I get it, the circle with the line across the center has a number on top and dots on the bottom. The number indicates the month and the number of dots indicates the week the part was cast. Right? Is it possible to have some dots inside and outside the bottom half of the circle at the same time? I found the circle on the tail casting of my transmission. Where is the circle located on the main body casting of the transmission? Thanks for the info.

Jim C.

Jim------


It's very possible to have dots outside the circle. Just what that means, I do not know. However, on the ones I've seen with dots outside the circle, there are usually no dots in the circle half. So, in that case, I suppose the dots outside the circle mean the same thing as dots inside the circle.

I don't recall ever seeing the bifurcated circle on transmission main cases. The main cases were a sand casting and the extension housings were a die casting. I have only seen the circle on die castings.

[Ronald L.]

Re: 3857584 tail housing date codes

Jim,
Yes as Joe has said perfectly normal sloppy pattern setters.
Post a picture of the RHS of your case, the main number and th P date and I'll point to those for you.

[Wayne M.]

Re: 3857584 tail housing date codes

....I don't recall ever seeing the bifurcated circle on transmission main cases. The main cases were a sand casting and the extension housings were a die casting. I have only seen the circle on die castings.

Joe -- here's a 325 case off late '65 #22330 -- Canadian delivered; note the VIN derivative stamp, without the model year prefix; TFP for all but the first thousand or so cars. Both bifurcated circles are on the maincase. The month/week circle shows a 6 with 2 (or 3 ?) dots. The trans was assembled soon after, 29 June. The part # tag is for a wide ratio.

All the 325 cases and most of the '010' cases that I've seen have both circles, or just one circle with the month/week dots sometimes outside.

By the time the 1968-69 '660's were being cast, the date coding seemed to end. Then, with the '661' cases, they used that horizontal line with about 6 vertical lines (never really studied this characteristic to figure out what info it conveyed).

I've also attached a '383' bellhousing, with month/week of March/3rd week (of 1964).

[Jim C.]

Re: 3857584 tail housing date codes

So after reading the posts, there are date code circles on the main transmission case, or no, there are not? Like I said earlier, I definitely found one on the tail extension with a "6" and one dot. The dot was raised. I can't really post a photo, because my transmission is currently on my car, and its reletively difficult to see. I've got all the other transmission numbers straight. Now I'm just trying to determine if there's a date code on the main transmission case or not. If so, where is it?

I also asked if it were possible to have some dots in the circle and some dots outside the circle at the same time. My bellhousing appears to have a "2" on the top half of the circle, with four dots below which are also inside the circle. There appears to be one more dot, just outside the circle. Ever seen that before? Again, it's a little tough to see, and perhaps the dot outside the circle is just a casting flaw, if you could even call it that. The only reason I ask is because the four dots inside the circle appear to be the same as the one outside the circle.

Jim (who's having a lot of fun squeezing his fat head under his car to find little circles and tiny dots)

[Ronald L.]

Re: 3857584 tail housing date codes

Jim - yes & yes.

Circle with a number & dots and if & when they were sloppy those are outside the circle.
Here is an example of them out side the circle, most of them for 66 I have seen are outside the circle.

[Jim C.]

Re: 3857584 tail housing date codes

Hey Ron,

Thanks for the info and the photo. So the photo is the right side of the transmission case, and I think I see a "10" with two dots. Right? That means October, 2nd week. Right?

Jim.

[Ronald L.]

Re: 3857584 tail housing date codes

Jim,
Exactly and you can do this from the ground, though certainly easier on a lift, just get a bit of a line of sight to the case, sick the camera in there and fire away, the benefits of digital. Are you trying to ID yours or looking for something specific?

"Normal" casting dates on main cases are not that far ahead of the assembly stamp. At least in 1966 the data I have is pretty tight from casting to final assembly. Tail housings and side covers have more float, but for sure not 4 months or more.