DaveBerlinetta

I've read all the articles that explain why '87-later 700r4's hold up better. I even have personal experience with my own junk breaking down.
But nothing I've read explains how to ID (externally) a later date tranny.
Casting codes? Type of pan bolts? Number of splines? Alien markings?

Mikz86TA

iTrader: (4)

82-84 1/2 had 27 splines and anything after had 30 splines. Easiest way to tell if its a 87 or later is drop the pan and look for the auxillary valve body. But the best way is to get the ID off of it. If its a 82-84 the ID liiks similat to this ( 9 TA Y 0 M 12 N ) , if its a 85-86 the ID looks like this ( 6 MD 146 A ) , if its a 87-88 the ID looks like this ( 7 YK M Y 45335678-141 A ) and if its a 89-Later the ID looks like this ( 2 YD M 2 145 C ) . These series of #s all mean something as far as year, model, build date, etc. On the 85/86, 87/88 and 89/on the 1st digit it the model year. As in 85/86 the 6 is 86 and 5 is 85. On the 87/88 its the same. Also the 88 and later it is as well. Being a 1 is a 91, a 8 is an 88, and so on. Since the models stretched over a long period of time, you need to ID the year series 1st by the ID type. Notice how different each is. There is also a model code (MD) on the 85/86 sample and YK on the 87/88 sample, that will tell you more about it.

duckmanquacker

well said!!!!

darkride86T/A

Also the last 3 digits of the pump serial # on 88-up 700's should be 732.
That indicates that it's a 10 vane pump, used in the 88 and later trannies.
I read about that elsewhere in this forum but I can't remember where.

Mikz86TA

iTrader: (4)

Good info. Where is the Pump ID? I just pulled my tranny for a rebuild and would like to verify. The casting # on mine is cast big into the front. Its # 8654732. Top right. Also, is there a certain year that used the Double Priming Springs in the pump vs. the Single?

darkride86T/A

Mikz86TA, you have a 10 vane pump. The 8654732 is the pump"s serial/casting #. I believe they started using the double priming springs
in 1988, but don't quote me on that.

DaveBerlinetta

Thanks for the replies; EXACTLY the type of information that I was looking for. I know where I can get what is advertised as an '87, and an '89, but how do I know for sure?

Thanks again.

Mikz86TA

iTrader: (4)

I just read something about the 732 at the end being a late model pump. Also found mine to have the correct Aux VB port, the larger hole (.215") between the sealing rings which should make it a late 87-92 according to ATSG. I am guessing the double springs are present. I also found my Tranny ID is 91( I already knew) but that I have a VBody with the extra Converter Clutch Valve Port. IDK if the 91 had it (wouldnt think so) or weather the last tranny builder put it in there from a 87 model since I had no-ECM to control lockup. Im stumped on that...ANY INPUT? The spacer is a (EA) ID and OEM part # 8680144. That corresponds with 1991 and the model code from my tranny ID KWM. Im getting a new spacer plate tomorrow from Superior. This ones seen better days.

Fast355

iTrader: (2)

The improved 700r4s also have an extra rib added externally, near the 2-4 servo. It started in 1987 and is was still being used on the last 4L60E I looked at. It starts near the bellhousing, goes up and right to the servo, the down toward the pan rail. It is a raised peak cast into the casting, looks like a hill, with its base starting at the pan rail. I will post pictures tomorrow to show the difference.