C5_Taylor

So the 700r4 went out in my c4. I found a rebuilt for $1300 but I have so many projects I really can't afford that right now. My question is, is it worth trying to rebuild myself? I know how an automatic trans works but I've never been inside of one other than pulling the pan. I have a sizeable mechanical background and I have access to a full shop. The rebuild kit with a torque converter is $400 which sounds a lot better than $1300 to me. Any thoughts on the matter? Thanks.

tunedport85inject

There are some good pic by pic thread on the net , some good video from ATSG and obviously their manuals, not a piece of cake rebuild a 700r4 but doable. It requires some special tools to resize some teflon seals and spring compressors to remove snap rings. You can make your own tools lot of tricks about it ... And , at the end, your mech skill is an important part of the game

cudamax

No way would I'd say do your first trans that way. Go get a junk yard trans and Bench rebuild it with a cheeper soft kit and then Install that one one day and make sure you pull the governor out of your vette trans and swap it out on the bench. They are Special for those higher rpm shifts. Then rebuild your Vette trans and keep it

JackDidley

You can get a DVD how to video fairly cheap . I think it would be handy if you decidet to try it.

C5_Taylor

I figured I would get a DVD and probably a manual as well if I do try it. I know a 700 isn't an easy transmission though so I'm awful skeptical. Thanks for the second opinions!

cudamax

I don't want to discourage you in any way. If I have, thats not my Intent. I just want to let you know I've seen guys that have pulled those trannies and completely tear them down and could put them back together in the dark and they would work great for a long time.

On the other hand I've seen guys pull them, completely tear them down and then have nothing but problems and have to do-em over after putting-em back in the car. Some more than once.

You really need a trans guy looking over your shoulder the whole way thru a rebuild on your fist time. At least or really take your time, after reading the manual and a video or two, and you should rebuild a junkyard trans first and put that baby in. Then see how it goes.

Good trans guys are hard to find and by wanting to rebuild your own tranny says a lot about you and you just might be a natural at this. So by all means go pick up a junk yard trans and go at it. If you end up being good at it.

You could get a job at any Dealer. They always are looking for a good trans guy. Go for it. Those really are not that hard. Just stay a way from taking apart the Valve body and pay real good attention to everything about the front pump, and stock up on the Vasoline. Do just a normal rebuild for now and latter get into the trick High Performance Stuff

confab

Like an engine rebuild "kit" a trans "kit" isn't everything you need..

Can you do it? Sure..

tunedport85inject

Confab is a pro since he has his own tranny shop,and his question its a clear advice...the 700r4 had lot of upgrading during its service life.the bigger improvement was in 1987 when it was redesigned as 4l60,new auxiliary valve body and internals upgrade.lot of hard parts were upgraded ,you can open different 700r4 and find different valvebody arrangement,different oil switch,different valves,different specs for clutches packs from V8 and V6 aplications all informations are into the ATSG manuals,that are specific for 82-86 and 87-91 but for sure you can find some issues or misunderstanding during the way ...you need selective back plates when you end a clutch pack,since you have to measure with a filler gauge the specs between the last steel plate and the backing plates.you have to ceck everything for wear , may be the pump need a rebuild , sometimes the 2 part of pump body need a resurfacing or new one if they are worn out by the rotor and vanes....

C5_Taylor

Hey thanks for the input. I've studied some really in depth rebuild videos for the last 2 hours. I'm developing a good understanding of what's going on and what to expect. However why do you recommend attempting it on a junk yard trans if my transmission is already toast?

cudamax

If you can get a real cheep junk yard one. Do it only if you can drop the pan and find one without metal in the filter and all over the place and only you would need to get a junk yard spare if you drop the pan on your and it has a bunch of metal pieces in the pan. Generally if it goes and you find metal in the pan. A planetary set went south and or a front pump went bad. If you don't have a spare for 1 to practice on and 2 to get parts off of. Things will have to be put on hold and those parts aren't cheep.
It's always a front pump or a planetary on those. Hardly ever is it just a soft part that stops them.

Check this out. The guy does one in 6mins and the step by step book is a must and if you have a video recorder, use it when taking it apart until you can do it a sleep. Just record yourself
http://www.powerblocktv.com/two-minu...mission-part-1

C5_Taylor

It slips in 3rd and 4th I'm assuming the clutches are burnt, I have a really good transmission shop locally that agreed with me. the transmission is already out and I've already had the pan and filter off. No metal.

cudamax

Kool then You could fix that easy and forget a spare parts trans. Good luck Man and just watch and remember your Disassembly. Let us know how good it turns out.
Am-acoo-man

C5_Taylor

Thanks! I appreciate your help, I'll probably order parts soon and I'll post again once I get things rolling.

cudamax

If you really are up to it and since you are already there. Go with a shift kit. Their shouldn't be any slipping of the clutches for a Mush shift in your corvette trans. Don't think you will be complaining about it shifting quick and firm and that your trans will be lasting longer due to longer clutch life.
Also check and tighten up all of your Drums clearances. Find out from a factory manual where they should be at Assembled and shoot for the tighter end of the numbers by buying and putting in thicker hard parts. Most of all of them came out way past spec and past the looser side.
Also not sure on yours but the Mopars 727 Torqueflites drums, the Clutch apply pressure ports made the drum apply slow and ****-ided and by drilling a few extra ports it applied/slammed the drums straight and quick and by eliminating a clutch or 2 in the final drive drums along with full line pressure, made it a lot quicker down the quarter. Alot Quicker.

Cliff Harris

If you decide to rebuild it yourself I recommend having both the ATSG manual and the Haynes manual. The ATSG manual has line drawings and the Haynes manual has photographs.

There are two ATSG manuals, one for the early version of the 700r4 and a different one for the 1987 and later version (which includes the 4L60 -- same trans, different name).

One thing to watch for is to not use too much air pressure to test the lip seals. I blew out one of mine by applying 100 PSI. The manual says to use 30 PSI but I figured more is better...

This thread might be helpful:

https://www.corvetteforum.com/forums...and-tools.html

cudamax

Here is something to read about whats good and what really isn't
http://www.transmissioncenter.net/competition.htm

cudamax

These guys really take rebuilding these to a high level.
http://www.hotrodders.com/forum/1993...des-30072.html

cudamax

You might want to get this and a few other things.
http://www.transmissioncenter.org/700r4_Parts_List.htm





#4XX. 700R4 throttle valve elevated pressure spring. The original TV valve spring is a bit weak resulting in low line pressures and insufficient throttle pressure. If left uncorrected this can result in premature 3-4 clutch failure. Cost $5.00

cudamax

Here is a guy that did his first trans rebuild and took advice from a pro and wrote it all down
http://www.thirdgen.org/techboard/tr...0r4-check.html

C5_Taylor

Thanks for all the sources! I greatly appreciate it. I was planing to go ahead and go with an upgraded kit including a shift kit. I'll definitely read up on all of those articles this evening. Thanks for the help!