Muncie 4 speed Trans

[binky3]

I've got a Muncie 4 speed trans. I've identified it's a '65-'67 trans. I think. It has a 3885010 main case, a 3857584 tail shaft case, and a 3884685 side cover with 3/8 fine thread male studs(to attach the shifter rods).  I've also identified the "circles" on each case. It has 'NO' notches on the shaft and no drain plug(Did all M22's have a drain plug??)It has the letters/numbers on stamped on bearing retainer(piece inbetween the main case & the tail shaft case) "PO307". What is that??(rebuilder's #?). 

Then stamped on the main case, bigger numbers/letters(looks like from GM--like stamping the factory would do) "6Z142867"(or "1" maybe the last number instead of "7"). Is that some sort of factory number??  Thought I'd ask before pulling the side cover and count gears. Should inspect anyway. Help Please.

[bertfam]

P0307 is the date code (March 7th, 1966). 6Z142867 is the VIN of the car it came out of. In this case it came out of a 1966 Chevelle built in the Fremont, California plant.

Yes, all M22 tranmissions came with the drain plug but remember, transmissions may have been rebuilt and parts swapped several times over the years, so the only real way to tell if it's an actual M22 is to pull the cover and look at the gears.

Ed

[binky3]

Thanks Ed. Yes, I'll pull the side cover anyway now. The "PO307" stands for March 7th 1966 out of a Chevelle. How did you determine that please??

[bertfam]

Most everything you need to know about transmissions can be found HERE! The VIN code of 6Z is the indicator. 6 is 1966 and Z is the Fremont plant, and in 1966 they only built Chevelles.

Ed

[Kelley W King]

I believe Fremont built GTO,s in 66 also.

[bertfam]

You are correct Kelly, but I meant the only "Chevrolet" product built in Fremont in 1966 (unless they also built trucks, which I don't think they did).

Also, the M22 wasn't available on the Goat, but if this really isn't an M22, then it could be from a Goat. Is there a 1 or a 2 before the 6Z?

Ed

[JohnZ]

Put it in second gear and pull the side cover - M20/M21 gears have a 39* helix angle (top photo), and M22 gears have a 21* helix angle (bottom photo).

[firstgenaddict]

It's easy to see why the M22's are stronger....

[jdv69z]

Would a Goat Trans have the speedometer cable located on the other right or left side?

Jimmy V.

[firstgenaddict]

Same side

[JohnZ]

As I recall, Goats didn't use the 584 tailhousing with the speedo on the passenger side - they used the 429 housing with the speedo on the driver's side; not sure when they changed to the 584 housing.

[Kelley W King]

66 Goats were drivers side.

[Flowjoe]

As I recall, Goats didn't use the 584 tailhousing with the speedo on the passenger side - they used the 429 housing with the speedo on the driver's side; not sure when they changed to the 584 housing.

Were still driver's side in '69 (my 50K original is so)