Help ID 700r4!

[patmckinneyracing]

How do you ID a 700r4? Is there a stamping or casting number someone that would tell me where it came?

 

[patmckinneyracing]

Re: How to ID 700r4 trans

Nevermind I found the stamping. Anyone wanna help me research? The stamping is 5YZ051A

I went over to my buddy Johns (itsnotanova) house yesterday and picked up a 700r4, correct new cut driveshaft, 4 speed b&m shifter, and crossmember for 150$! That guy is cool as hell.

 

[anakputa]

google the trans numbers. Hopefully its an older one and its good. You will only need a module to lockup the converter. I thought I bought a good one cheap and it only lasted a year. (5 speed stick now)

 

[patmckinneyracing]

Nothing is popping up except this topic on google when I put that number in. There is also MD8 raise lettering on the side of the bellhousing.

 

[MrHernandez]

Dunno but i overheard someone say the "K" code is the one you want because it was used on v8's, then again maybe they said thats the one that was used on 4 wheel drives, sorry, i forget, none the less you lucky b*st*rd, I been trying to find a 700r4 for cheap and you got a shifter and x member thrown in for $150

 

[patmckinneyracing]

Don't forget the proper cut driveshaft too, needed that since I snapped mine in half lol

 

[jrm81bu]

Hopefully its an older one and its good.

Why would that be? The newer ones have a 30 spline input shaft vs. the older with 27. The newer 30 spline would be the better one. At the same time you wouln't really want one that was so new it was a 4l60e, because of the expense of the controller.

 

[patmckinneyracing]

All I know so far is that it is a 1985 trans, on the side of the bellhousing is MD 8, and it is supposed to have a 30 spline count by that time.

 

[MrHernandez]

i believe the 88 and later 700r4's are supposed to be built a bit better, not sure how much but i was told to get one of these if i could....anyone else ever hear this?

 

[patmckinneyracing]

From what I could find on the net and other forums, the first generation was from 82 to 84 with a 27 spline input shaft that was weak and followed the design of the 2004r. Then in 85 they beefed it up with the 30 spline input and I believe some better internals such as a 10 vane oil pump etc. This is the second gen. The third gen 700r4 goes from 87' onward and is what you mentioned MrHernandez and is supposed to be the more reliable and sought after. IMO the second gen. is similar to the third and the only reason it would matter is if you decide to go without a rebuild. I would not do this with any used transmission.

Maybe I need to go onto other forums. The corvette and F body guys are very interested in the 700r4 while GBody is aimed more at the 2004r, since it is a direct swap for most. Problem is that everybody wants stupid money for the 2004r's and they probably cost more to beef up to hold under power. With the 700r4, it's a truck transmission and is made to hold up to some decent power. The corvettes and camaros used them throughout the 80's instead of the 2004r so they can't be too bad. Got a buddy with a 92' chevy stepside with a pretty strong vortec 350 and 3.73 gears and is still using the stock 700r4 without a rebuild. The key in the longevity of the overdrive transmission is cooling. If you don't have an extra transmission cooler, along with the one built into your radiator for those who do, then standby because that trans is gonna get hot. Only reason I bought this one is because it was practically "FREE".

I just want that 4th gear to go with my 3.73's. I'm tired of that high whining engine on the highway, it gets old.