4l60e 94 only 13 pins or 12 pins on plug????

[spasticone]

Ok... I'm having some real issues trying to find the right used tranny... call me cheap, I don't care, but please help me with something constructive to aid me in my pursuit of the truth.

My transmission plug has 13 pins and EVERY other Blazer 4l60e that I looked at so far has 12. I was told by a freind that knows trannys that it has to do with the "FWM" on the front casting behind the convertor. Most junk yards told me that "94 only" was listed for an interchange, but I looked at at least 14 blazers with build dates ranging from 1/93 to 6/95, ALL with the old body style and EVERY one had 12 pins. WHAT GIVES!!!. I want to slam a tranny in this thing and sell it, but I'm told the 12 pin, or the "non FWM" transmission will throw codes and send me into limp mode. ANY info would be VERY much appreciated. Thanks in advance. Kris

[MT-2500]

The 13 pins were more on a 1995 trans.
What is your build date and what engine?
Does it have a VCM or PCM? Computer on right fender or under dash?
MT

[spasticone]

Ok... here's what I have. It's a 4.3 W, 4x4, build date: 12/9# (Of course the last digit is rubbed off.) I'm guessing it's 94, making my blazer a 95 tranny???? Didn't check the computer part yet.. Snowin like a fiend here.

Here's a nice little tidbit. I looked at a blazer in the scrap yard that was build date 6/95 with the old body and the non-balance shaft motor with metal valve covers(a 93 drive train??). good greif Charlie Brown. This is discusting.

[blazes9395]

For a '94, yes your friend is right you need a non PWM(pulse width modulated) tranny. The 4L60E(has to be electronic) out of a '92,'93,'94 will work, as these trannies are non PWM trannies, with a on/off torque convertor. The PWM came in for the '95 model year, and was changed again for the '96 model year again. Another unique thing for the '95 model year.

[spasticone]

Just to finish this problem out.... My 94 blazer has a 95 tranny. It also turns out that many built around the same date have 94 and even older transmissions so WATCH OUT! It seems these years were a dumping ground for leftover "stuff" I got a 95 with 78k on it and just finished puting it in. Yuck what a S&@&# job. I was covered from head to toe in old dirt stuck to my new, seemingly perminant layer of atf. Well, thanks for the help.

[MT-2500]

Glad you got it going and figured out.
I have torn a lot of trans down and the built date on the trans parts never matches the year of the car.
Always about a year off for some reason.
MT