[corwin69]

Originally Posted by JonRunaas

Hey Guys, need some advice here
I'm gearing up (no pun intended) for my summer project of getting my 78 Impala coupe up on the road. It has a bum tranny in it and I plan to swap in a 700R4, and rebuild (or have rebuilt) the stock rearend with limited slip and 3.42 gears. I will be using it for 90% street/highway driving, with 10% ecclectic mix of drag racing (purely for fun, nothing serious), goofing around and pulling small/medium sized trailers. I am planning on a torque converter with similar specs to TCI sizzler or saturday night special. I would consider myself very mechanically inclined and patient, but also very inexperienced. Ok, that is the background info, now on to my questions:

1: Should I attempt the tranny rebuild myself, or have a shop do it? I would love to learn how, but I also don't want to bite off more than I can chew. How long would it take a beginner to rebuild the tranny, if he had a good manual and maybe one of those rebuild videos?

2: How much should I "build" the tranny for my uses? In a perfect world I would want crisp, strong shifts when I am pulling a trailer or accelerating hard and smooth, comfortable shifts when cruising around town. How should I accomplish this?
Also related to this, I notice in the catalogs all sorts of rebuild kits with heavy duty clutches, bands, etc. Are these necessary for my uses? Will they increase the life of my tranny?

3: I would like the ability to hold the tranny in the gear of my choosing, eg. when engine braking down long hills, etc. What is the best way to accomplish this?

4: Any other advice you guys have for a newby?
Any help would be greatly appreciated! Thanks a bunch!

If you have never rebuilt a tranny before I wouldnt try it unless you have some one to show u. Atlearts get a good book at a good trans parts store. this trans is alot like a 350 just added extra gear and valbody. Ive seen ppl pul out a tranny the build alot just cuz they got the year mixed up and put 1 checkball in wrong place.. you will need some special tools and know how to do the valve body. Need to put a shift kit in it. If you have never done a tranny before I wouldnt do it. Ive been doing it for over 30 years. I have 3 700r4's im building. 1 full race i street/strip and a stock one with shift kit
For keeping the tranny in any gear you need a -3 shift kit or a new valve body full manaul. U dont want that on stree get a -2 VB Thats a lower kit thats nice and still auto. For what you want find someone thats good to build it for u. It will cost about 1,000-2,500 depending what u want with torqe converter. Hope I helped im going out to work on my trans.

[corwin69]

Originally Posted by Mad Machinist

So I'm not sure how much I can tell you about rebuilding a 7004r, but I can tell you something about driving one. It will "hold" its gear without any modification whatsoever. Almost all non-computer GM automatics will. If you put the shifter into "2", it won't shift past second. It'll downshift to prevent stalling if you slow down enough though.

Not true. If the RPM's of a computer get to high it will shift, also if rpm are too high it wont down shift. You put a shift kit it it will work, I put some kind of shift kit in all 700r4's I do. They never run just right without one. Also reverse will go in gear slow. There is a hole that needs to be put in rev piston that helps.Put the kit in u can put in 1 geat at 6000 grand, stuff may blow up ..lol He said manual mode. That makes the tranny full manual. You have to shift like a stick shift.. Unless ur on Race track all the time dont go manual -2 shiftkit is best.

[tnsmith10]

Originally Posted by corwin69

Not true. If the RPM's of a computer get to high it will shift, also if rpm are too high it wont down shift. You put a shift kit it it will work, I put some kind of shift kit in all 700r4's I do. They never run just right without one. Also reverse will go in gear slow. There is a hole that needs to be put in rev piston that helps.Put the kit in u can put in 1 geat at 6000 grand, stuff may blow up ..lol He said manual mode. That makes the tranny full manual. You have to shift like a stick shift.. Unless ur on Race track all the time dont go manual -2 shiftkit is best.

if your having to install some sort of "shift kit" for each 700r4/4l60e you build, theres something wrong.
ive done plenty without any kind of modifications and they worked just like theyre supposed to.
the most common "kit" that gets installed on a 700r4 is the sk jr by transgo.

to the OP, the best booklet to get to help for rebuild would be the ATSG blue book. do a google, theyre easy to find.

[Crosley]

corwin69 posted to an old thread.

[tnsmith10]

i was wondering why i saw quotes but not the posts from the quotes.

[fierosum]

There's also a green book. What's the difference between the ATSG Blue book and the ATSG green book?

[tnsmith10]

the green book is an update supplement manual.