oldsmoboogie

I bought a pile of parts when i bought 455 for my cutlass i got 2 muncies in the deal and was told one of them was out of a 442. I was hoping someone could help me decode the numbers and tell me if its for an olds. First of the speedo cable is on pass side and the number on the case is 3885010 and the number on the tail is 3857584. It needs rebuilt and if its for an olds i will keep it and rebuild it if not i might just buy a new one thanks in advance for any help.

wmachine

Look for a 4 or 5 digit date code stamping that starts with P.
Also look for a VIN derivative stamp. That will help zero in.

oldsmoboogie

There was a number that read p1020

wmachine

That would make it a '63-'66 trans, Oct 20th build. The year wasn't included until '67. What is the spline count on the input shaft and is it one groove or two?

ethn_bert

Yes that is a muncie. The question is which one? 3885010 = 1965-1967.
P1020 = Muncie Plant 4 speed(P) Oct 20th;

Since your trans casting number is 1965-1967 and your date code is numbers instead of letters that transmission is 1965 or 1966.

To figure out the ratios/type list the number of rings on the input shaft and the diameter of the cluster pin. 65-66 all muncies had a 10 spline input shaft.

No rings= M20wr or M22cr <-open up to tell difference(cluster pin size)
1 ring on input = M21cr
2 ring on input = M20wr



http://www.5speeds.com/muncie2.htm
http://www.dandltransmission.com/muncieratio.html

Good Luck

oldsmoboogie

It is a 10 spline and has 2 grouves. Is there anyway to tell if its olds specific or did they just put whatever trans was available in the cars as they rolled down the line? Thanks for the help

ethn_bert

M20 Wide ratio. An oldsmobile muncie would have a BOP bell housing . Just kidding. The transmission is no different for an oldsmobile or chevy or any other. The bell housing is the difference.

The only difference would be the VIN derivative would be brand specific and vehicle specific. Do you see any VIN stamps? Could you decipher the VIN derivative(Most likely need to know what brand of car it came from)?

Good Luck

66400

3885010 case was used for 66 and 67 model year only. Date stamping code of P1020 would make it a transmission for a early production 66 model car.

Henry