Thread: tranny question

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Hey guys , I got a chance to buy a 700r4 out of a 87 iroc-z for $100 . I'm running a th - 350 now , in the 55. The tranny is good , rode in the car shifts clean , no weird noises , he's puttng in a speed and said he sell t to me. I'm no tranny wiz but what would I have to do to make it work in my car , I know there are some elec stuff like the overdrive lockout valve , I know this cuz one went bad in my 87 monte ss years ago. any help would be appreciated.

I did this years ago to my father-n-laws 55. It was too simple. As for the electronics, the only reason you will need to mess with that is if you want the torque converter to lock up and not slip. There are lots of after-market companies who can help with that like Painless Wiring, or TCI Transmissions, etc.

The only thing additional I did for my father-n-law was to install a different plastic gear indicator to show the overdrive between Nuetral and Drive.

If my memory serves me right, I had to move the crossmember a couple of inches. He still has the car if you need me to look at it for you.

You shouldnt have any problems. Let me know if you do.

Troy

Thanx for the feed back . I'm going to call a tci and b&m when i get a chance to see if they got a wiring kit.

I almost forgot...Make sure you adjust the kickdown cable before you go out on the road. The 700R4 is very delicate if this is out of adjustment.

this link should help with the cable adjustment:


http://www.classictrucksweb.com/tech/0307cl_cable/

From 82-84 avoid like the plaque, they have the 27-spline input shaft, and have durability problems. 85-87 can be upgraded.
This can be found in Hot Rod Magazine March 1995, the article is called "THE GREAT DEBATE (700r4 vs. 200r4) Which is a better overdrive."


If it were me I'd jump on it. That is a great price for a 700r4. I have a detailed instructions for beefing up 700r4's if you want them let me know.

If you can't stand a 350 Turbo, then go to the 400. I honestly don't understand all the hype about the 700R4 all over the perfomance mags today. The shift quality in a stock 700R4 is dismal at best, and the things weigh a ton. I guess everybody loves that bitchin' low gear, it makes a 350 Chevy haul ass like a big block, but it's all over in 2nd. And, if you do manage to stay with a 5.0 Mustang through 2nd, you're going to see tailights when it goes to 3rd and slips into lockup. What crapola! 350 Turbos are better trannys than most people want to believe. I've overhauled about 40 of them over the years, and only had two that were beyond salvation. They can handle any smallblock, and with a good intermediate sprag clutch, they can tackle a big block as well. I can't deny that a 400 Turbo is GM's finest effort though; you cannot beat them for shift quality and durability. A 400 weighs about a ton as well, but in this case, it's worth it.

I'm not just blowin' smoke here, I'm driving a '90 Chevy 1/2 ton with a pretty tough 700R4 in it on a daily basis. For the most part, I don't use the overdrive unless I'm on the highway, since it's always shifting into it at exactly the wrong time. As a matter of fact, I generally shift this transmission manually every time I drive the truck. The thing just doesn't seem to know when to shift, so I do it for it. Low gear is a blast, but it's more or less useless for anything else than showing off. I much prefer the 350 Turbo in my '79 Chevy 1/2 ton, it knows exactly when to shift, and it has performed flawlessly since 1979 (26 years and counting) without any more than an occasional fluid and filter change.

I'd think very seriously about going to a 700R4, it's a lot of trouble and EXPENSE to go to for dubious benefit. And besides, how come GM couldn't even call this one a Turbo? Were they ashamed of the mess they made redesigning the 400 into an overdrive, and felt like it wasn't worthy of the Turbo lineage? That's kinda what I think, although I don't have an explanation for using Impala and Malibu for those atrocities that now bear those once proud names.

If you plan on using the overdrive on the 700 make sure you get the lock-up torque converter working. If not it will create a lot of heat in overdrive, especially if your running a highway gears.

i think the 700 is the way to go. if you build these units right they can hold up to 500 ponies.

your biggest concern at this day and age is gas mileage. and with that fourth gear and lockup it will be cheaper in that shoebox.

my advice is before you put it in the car get a well known and respectable builder to go over the unit.

from the factory these units are junk. but after a few updates they will last for along time.

just a few insights on udates for this unit are.

1.the beast reverse sun gear shell
2.29 element dual cage sprag
3.get a good 3-4 clutch pack setup (red eagle)
4.hardened pump rings.
5.10 vane pump some go to the 13 i dont think its necessary
6.2-4 servo get the 093 . firmer 1-2
7.trans go jr. shift kit.
8.new boost valve

there is a ton of more stuff to do if its in your budget ,just make sure to buy a decent torque converter , if you dont that good trans will get eaten up .

putting the unit in the car is a snap
definitly have to get the lockup to work or you will burn up the trans, lockup actually cools the fluid
the tv cable must also be adjusted correctly . this is what controls throttle pressure in the trans . hope this helps