What is the difference in earlier and later 700r4's

[rs74]

What makes the later 700's so much better than the earlier versions. In what year did they get better. Can the earlier trans be upgraded or just have to get the later one for a better trans.

[beamn7]

Get an 87 or later. 87's and up have the aux valve body. TOTALLY avoid pre-1984 (had smaller 27 spline input shaft vs 30 spline and multiple other concerns) 87-91 are typically the best of the mechanical speedo 700's.
Always start with a good core and be sure to use 'the beast' reaction sun shell, updated 30 element forward sprag/roller clutch, alto 3-4 clutch kit, larger boost valve (.500 max, I prefer .470 for daily driver), alto wide 2-4 band, new bushings, replace 7 vane pump rotor with at least the 10 vane kit if not a 13 vane kit. You don't always need the "corvette servo" but will get the most holding power in 2nd with it. 3 sizes were made and I usually use the middle size (don't recall specs off hand, have at home but traveling for work this week) Wire torque converter to only apply in 4th. Many kits available to accomplish this. DO NOT run this trans for any extended period of time without the converter locked up in 4th. They like to and most likely will overheat. Also get a LPD pressure drop cooler from True cool. Wire wheel off the paint on the sealing surface of the front pump seal and install with red loctite along with the factory retainer. Hardened input housing (if you are putting over 375hp) and certainly one piece seals rather than slash cuts on the input shaft. Those are just some of the things that come to mind after dusting off my memory banks......

Good info https://www.atsg.us/atsg/gm-manuals-1.html

Hope this helps.
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[rs74]

WOW! That is some good info there. Thanks. I am looking at an 84 4x4 and it has the 700 in it an supposed to be rebuilt two years ago is why I ask. I also have on in an 85 K10 as well but it doesn't run. Thanks I appreciate the info.

[beamn7]

They are a great trans when set up right. I have an 87 version in my 85 and have put it through its paces towing, etc..... Yours should at least be the 30 element trans so that's a big plus. I say if the fluid looks good and smells good, don't worry about it for now. Remember, some clutch material is normal but the fluid should be red and not smell burnt. If its dark and smells burnt, then the clock is ticking...... You can always get a good core and build it so you have one ready to swap in....

Best of luck,
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[1977cheyenne_C10]

how can you tell what transmission you have and what year?

[silvereagle07]

Tags and casting numbers on the side of the transmission.

[rs74]

beamn7, are there any rebuild kits that have most of what you are talking about that you would recommend?

[gchemist]

I have an 85 Camaro in my truck. A long tail shaft was added. Built to take all HP I can put down. Costs $2k+!! Worth every dime to me. Killer shifts and response.

[Rich84]

My 700r (and TPI) came out of an 85 Camaro too.. The 1st to second shift is firm but the 2nd to 3rd is a little mushy..Fluid looks good so I'll just keep driving her..

[beamn7]

Work with these guys. I have in the past and they are great to deal with, reasonable prices and have all the different parts / kits you need.
http://www.transmissioncenter.net/