So I get this 700R4 rebuilt about a year ago and it works fine for about 6 months. Then it looses OD for about 4 months then it comes back. A month after that, it loses OD and 3rd gear. Now it will only drive in 1st and 2nd. I can't afford the gas on that crap. I have to act soon and I don't think I have many options. I took it to an AAMCO and had them do a diagnostic. They said to have it rebuilt again and they would charge me $2,000. I said yeah, right. Alternatavely, I could buy a "working" one from someone local for relatively cheap and run on that until it dies. I've screwed around with the car a lot to try and get it to shift and it just won't. I'll describe it's behavior and see if you guys might be able to suggest something I haven't tried yet... just to give it a last chance before I change it out.

P-R: Good

P-OD: Nothing/Like Nutral

P-D: Starts off in 1st good, will not shift into 2nd at full throttle/ shifts at 1/2-3/4 throttle at 25mph, will not shift into 3rd; redlines

P-2nd: Goes to 1st, tries to go to 2nd @ 25mph and slips into "nutral"

P-1st: Good

Manual Shift D-2nd @60mph+: Stays in 2nd for about 2 seconds then slips to "nutral"

Powershift D-OD @ 80mph+: Will not grab

D-1st @ 25mph+: Stays in 2nd and will shift to 1st when speed drops under 25mph


Any suggestions to help me out would be greatly appriciated. If someone gives me information that ends up fixing my existing tranny, I wouldn't feel guilty paying them a little something for making my life 20x easier.

*EDIT* Oh, yeah. By the way, the downshift from 2nd-1st is very, very late; keeps the rpms high most all the time.

 

What year tranny is it??? The early 700s sucked. Very easy to blow with bad front pump problems. once they did blow, if its not cleaned 100% and a new TC used, this is what happens.

Ya build it, it blows, they say Ill build it again and the pattern continues.

When they first came out and did blow.
Most shops would not rebuild them after they went. putting a warranty on one was costly as 50% of them came back.

 

It's an 85'. They introduced the 700r4's in 83', right? I hope the one I have isn't too early. According to the previous owner the transmission fuctioned just fine for about 17 years before it needed a rebuild. It had roughly 220,000 miles on it when it was rebuilt. A really cheap 700r4 near where I live has about 150,000 miles on it, may or may not have been rebuilt, and is said to work just fine. I guess I should go with that? Is there something I'm missing with this one?

 

No they sucked till like 87-88 when they changed the pump, I oculd be wrong on the date.

buddy had an 86 monte carlo with like 70,000 on it. Front pump went and no one would touch it.They all said buy a new ones.

he ended up putting in a stick.

This was also 10+ years ago but no one would rebuild it as unless it super cleaned, tranny, lines, cooler and all super duper clean, it will fail again. most likley. not allways but its not like rebuilding a blown th350 and you know it will last forever.

a tranny needs built after 100,000 easy. it may still "work fine" but its not a reliable part. Just find the newest, lowest miles one you can find.

call junk yards and try to get a warranty.

People come up with low mile 4gen motors all the time.
so there must be low mile trans too.

 

I have SEVERAL of them.

No real complaints and they are about the best OD tranny you can run in a street driven car/truck with 250-350 hp.

There were several "upgrades/updates" made to them thru the years but the old ones were not exactly junk like some folks think.

If I had an old one 83,84,85 and I wanted to rebuild it I wouldn't hesitate to do so.

The pump in yours is good. If it wasn't you wouldn't be driving in ANY GEAR.

Sounds like you have a little trouble in the valve body area.
Could be a weight thrown off or a spring thrown off your govenor. A simple/inexpensive fix.

Your TV could be stuck and that will cause it not to shift or shift HARD. Most times it feels like you have to rev to 5000RPM to get it to shift.

You need to find someone that knows something about these things to check it out for you.
Someone that doesn't feel they need to make thwir whole lifes fortune just on this one tranny.

BTW, GM STILL makes then and installs them. Must not have been such a bad design if they've managed to use them to this very day.

I have one in my 98 Z28 LS1. Works great. I have an old one in my 84 Vette. Works great. I have a newer one in my 91 Vette. Works great.
They were putting them in Corvettes up until 2005.

If you want to work on it yourself, check the govenor first.
Then remove the valve body and clean all the valves up. Focus highly on the TV. It controls the pressure in the tranny which controls how/when it shifts in conjusction with the govenor.

The 700R4 is a FINE transmission.
Just get it fixed, it'll be fine.

 

Oh, IMHO, STAY AWAY from AAMCO.

They ALWAYS say you need a complete rebuild.
RUN don't walk from them.

My opinion based on experience.

 

I had that feeling when I talked to these guys. I'm a salesman myself and I knew that just by driving the car and tapping the underside of the tranny with a pen they knew I need a rebuild was BS. I'm bringing the car into the garage tonight to update the interior; I'll do the herky jerky with the TV cable and take on "the govenator" if I have time. Thank you for your input; greatly apriciated.