1987 Suburban V10 4X4 700R4 Trans id???

[Burb restorer]

Greetings and good evening to all. I am trying to figure out something with the transmission code on the 700R4 in the 1987 Suburban 4X4 I am restoring. From everything I have been told, the code on the right rear of the transmission suggests that I have the auxiliary valve body 700R4, but I DON'T. It is NOT a "K" case either BUT, here's the code: 7TXM-Y-00525758-276B. AND, MD8 is cast into the case so at least it's a 700R4, that's for sure. It DOES have the 6 bolt holes for the aluminum flywheel cover. There is NO parting line running on the right hand side of the transmission and there are pressure line plugs on the right hand side. Funny thing is that the code is NOT stamped like from a set of steel letter/number stamps with a hammer but looks to be imprinted with tiny dots, maybe laser etched? Hope I have explained this without too much confusion. Any idea what transmission is in this thing?? The RPO codes in the glove box have 9MD8 listed. I want to rebuild a stouter transmission and can't seem to find out if I can put in a 700R4 WITH the auxiliary valve body in place of this one...…….I keep seeing info that says "1986 and up had the auxiliary valve body", well, I don't know about that.

 

[bucket]

The '7' at the start of the code denotes the model year, doesn't it? I could be mistaken, but I believe there were 'K' cases that did not actually have the 'K' cast into them... they simply got the name because of the big 'K' on them, when really 'HD' would be a more fitting name for them. Anyway, those are just my thoughts and I could be completely wrong. It's been a while since I swapped 700r4's around.

But I can say with certainty that 86's didn't have the auxiliary valve body. Or at least not in cars. I was under the impression that '87 was the first year for that.

 

[Burb restorer]

Hey thanks for the quick reply. At least the 6 bolt holes for the flywheel cover designates it for 4WD. I am wanting to know if I can replace it with an auxiliary valve body transmission as a direct bolt up without having to modify/change anything. Since the 700R4 shift points are hydraulic and not electronic, I don't see why not. Anyone else out there successfully perform this task? I finally was able to post a decent picture this morning.

You must be registered for see images attach

 

[HotRodPC]

If I had to guess, I'd say it's probably an Early 87 case. If I get a chance, I'll see about digging out my Changes to 700r4 book and it'll tell me what month and year of production changes were made and when the Aux VB was included. I think I see a pressure tap on the side of the case too in that pic. Those pressure taps on the side of the case also designate earlier case. I hear that are some later cases that also have the pressure taps but they are fairly rare and probably only in the transition year only.

Yes, you can run a later Aux VB transmission and it'll work just tine.