Rebuilding a 700r4

[Russell]

Hey fellas, on a scale of 1 - 10, how tough is it to rebuild a 700r4 tranny? I wanna beef it up a bit so it can take my 355 later on (300 - 350 hp, and 350 - 400 ft lbs of torque is what I am aiming for)

What all is involved with this, and do you think that a kid like myself could do it? The tranny I am getting worked when it was removed minus a bad front seal, but it has a lot of km on it, so I would like to rebuild it right away.

Also, I seem to have a longtail TH400 (if such a thing exists, just a heck of a lot longer than the four speed granny I have) so would I need to get a new driveshaft as well?

My father knows a guy who owns a transmission rebuild shop who would likely be able to get me fairly cheap parts for it, so I'm thinking it may be worth it..

[1FaastC10]

on a scale of 1-10, i'd put it at about a 12. lots of special tools required, lots of very critical clearances in there, and dirt must never find its way into the trans.

[Russell]

Originally Posted by 1FaastC10

on a scale of 1-10, i'd put it at about a 12. lots of special tools required, lots of very critical clearances in there, and dirt must never find its way into the trans.

Sounds like fun

What kind of tools do I need? I'm sure the guy has them, but borrowing them may possibly be a different question, lol

[TwinTurbo]

There are no super special tools required. Get the ATSG manual, the TransGo (NoYoYo) video and manual and you will be able to do it yourself. Just lay everything out in the order it came out, work in a clean area. Contamination is the biggest enemy of an auto tranny. If you have the early 700R4 with the smaller oil pump, get the upgrade stuff for the larger pump, stronger drums and clutch packs that hold more clutches.

[SanitysBane]

i would put it at a 4, the hard part is getting it out, special tools? just get something to pull the front pump off and the rest just slides out, take a hammer and tap in the 2-4 servo enough so u can get the ring out, u will need a pair of snap ring pliers, and that 700R4 if built right can easly handle any small block

[79BIG10]

If you have a Th400 in there now then you will have to change out at least the yolk. the splines are different count on a TH350/700r4 compared to a Th400. If you find a d/s from a truck like yours with a 9" tailshaft for a Th350 then it will work. You then just need to slide your crossmember back and redrill holes.

[Russell]

I have snap ring pliers here, so that isn't a problem, what other special tools do I need, and where can a guy buy a book on this so I can do some reading up on it and know what the specifications and such are on it?

Brandon -- So all I need is a longtail TH350 driveshaft and it'll be good? Will the TH400 crossmember work with the 700r4?

[SanitysBane]

you are also going to need something to pull the front pump off, as foor a book, get a guine helms shop manual, one for an 1988 and to about a 92 or so truck, firebird, corvette, or camero(borrow from some one or libary) also read the manuals that come with the parts(B&M shift kit etc.) thats the biggest thing for a 700R4 to handle any amount of power. The 400 crossmember will work, u will just need to move it around alittle bit and that will be good, and y not just get a drive shaft for a truck that original came with a 700R4? it shouldn't be that much money to do so.

[SanitysBane]

p.s. the helms is a guine chevrolet book, all others suck, there not worth burning

[Opper77]

Russ, the crossmember will have to be moved.. My frame had the holes already in it, but some mods were required to make it fit.. And the driveshaft will need to be modified, cause the yoke is different..

Also the th400 is electric kickdown while the 700r4 is mechanical.. i went from 700r4 to 400 so I had the easy route, you have more work ahead of you.

[1972C10]

700-R4s arent the best to learn on Must be fairly clean Unlike a th350 or 400 you can almost build one of them in the sandbox.

If you do build it get a hardned sunshell a vette cervo and it will shift nice and firm and wont have to worry about the sunshell shattering if you get out in the mud or loose traction and then regain it .

Shift kits dont seem to work out as good in those as they do in a th350 if you put one in do a mild shift kit a full out tends to break stuff inside the transmission

You had better hope the pump isnt stuck sometimes it takes a special tool to pull them

and it is a the same lenght as a th350 longtail like those trucks come with i happen to have a driveshaft out of one if you need the dimensions for comparision.

You will need the tv cable bracket If you cant find one let me know ive got a few most intakes have the holes for it seems even old ones have hte holes there but i think they were used for coil back then .

If you want a little higher stall speed than a stock convertor without a large price get a camaro convertor they 2100 stall as opposed to the trucks 1800 not alot of difference but same price .

And you might be better off to have it done Friend of mine did his and it was bad ass for three days after that it puked out .

Im about to have to get a 700 benched its only going to cost me 575 with the 30 dollar vette cervo and a shift kit

[RockHQ]

The 700R4 is factory rated at 350ftlbs. The 200R4 is factory rated at 330ftlb.

[SanitysBane]

my 700R4 is holding to over 500 ftlbs. as for the shift kit, the harder the transmission shifts, the easyer it is on the clutches, and if u want the thing to last any time, go with the 'vette servo, and goviner, as well as kevlar clutches and 2-4 band, it may cost more but it will last a lot longer. the basket also tends to brake around the weld, get a corvette one and your good to go,

[TwinTurbo]

the B&M shift kit is junk, it unnecessarily raises the line pressure, giving the harder shifts. The NoYoYo (TransGo) kit is much more sophisticated with new valving. If you do upgrade, get that one instead.

[SanitysBane]

the higher line pressure gives u harded shifts which is good, because a good hard shift doesn't allow the clutches to slip into place, in turn it will make the clutches last longer and will also be able to handle more power

[79BIG10]

Originally Posted by Russell

Brandon -- So all I need is a longtail TH350 driveshaft and it'll be good? Will the TH400 crossmember work with the 700r4?

If it's a 9" tailshaft and the same length bed as your (LWB or SWB) then you're set. Not sure about the crossmember but maybe someone else can jump in on that. Also look here for more dimension info http://www.tciauto.com/tech_info/trans_dims.htm

[TwinTurbo]

The noyoyo kit also gives hard shifts, but only when you need it..on the throttle. Not at cruise or low throttle settings, then hard shifts are just downright annoying. It's a far better kit in every way possible, the B&M kit just raises the line pressure really high all the time to achieve the hard shifts,....band aid.

the B&M kit makes you remove 2 check balls, the check balls is what makes the shift smooth, without the check balls the pressure (fluid volume) won't have to take the small orifice path but can go through the big passage, slamming the clutch packs on, there's 2 balls to be removed, one for 1-2 shift, the other for 2-3. You obviously don't remove them from P-1 or P-R

The TransPak kit is not the same as the shift improver kit (shiftkit is a TransGo term), the TransPak also allows you to set it up for manual/auto and can be set up for either race/street/tow.

The B&M kit is a kit designed to be added to a tranny that's installed in the car, the TransGo kit contains a lot of items meant to imrpove reliability of your trans, it beefs up the power handling and tackles known problem areas, whereas the B&M kit just creates harder shifts.

[1FaastC10]

there is a difference between a "hard" shift, and a "firm" shift. hard is bad on hard parts, and hard parts are not cheap. honestly, Russell, judging from some of the questions you have asked on this board (and i'm not trying to put you down here, i mean this with the most respect) i would highly advise that you leave this fix up to a professional. as i stated before, lots of specialty tools required, and lots of VERY critical clearances to be set. plus, if it gets screwed up, you dont have to do it all over again. just take it to whoever rebuilt it and let them deal with it.

[Russell]

No offense taken, and yes, I know I've asked some dumb questions, lol

I guess it might be best to get it redone professionally, just that I don't have 600 USD kickin around for the tranny...

[SanitysBane]

its not hard at all to rebuild a 700R4, all u need is a helms shop manual for a 1988-1992 chevrolet or gm truck, camero, or firebird. just follow the prosses as described by GM for a correct rebuild. the guys down at your tranny shop don't know how to properly do it ether. if i persoanly had the option i would go and spend about 300 bucks on parts, shift kit(B&M preferd because its easy on the clutches and the hard stuff will brake eventually as well mainly that basket) and get a corvette 2-4 servo, basket, and goviner. by yourself some kevlar clutches and the largest 2-4band you can find, and get a pair of snap ring pliers. to remove the 2-4 servo just get a hammer and LIGHTLY tap it into the case, till you have enough room to remove the ring. once that is done then all u need to do is to remove it by getting a pair of channel locks and a rag, put the rag around the nub, and then put the chanel locks on and spin the 2-4 servo till it comes out. for the front pump, none of them are easy to get out, i have reubuilt over 20 700R4 and all of the front pumps stuck, just some worse than others. what i use, is a steering wheel puller, and a clamp, clamp down the stator on the outside of the pump, very tightly and then put on the steering wheel puller, get some long long bolts with some large washers on them, and off it will come. it works, i've tried doing it other ways but this way works best. also when u have the transmission apart be shure to rebuild the front pump, its jsut a little vane kit but not using is really bad. i had the front pump on one of mine go out and caused it to not shift into over drive, and wouldn't shift untill really high rpms, but that problem got fixed. as for the transmission is selft get a 4L60, not a 4L60E. the 4L60 and 700R4 are the same, the 700R4 was the early modle and couldn't handle anything at all. if you want the best band for your buck try to get a 90 to 92 camero or firebird 4L60/700R4, this will have the 2-4 servo and goviner on it. me personally wouldn't want to spend the extra 300 or so to get it redone and spend the money on otherh items. but thats jsut me. the hardets part about rebuilding it is lining up the clutches when u put it back together. i would advise that u replace everything that u can, besides the output shaft, inputshaft, and valve body. i used to get my parts from www.bulkparts.com but they are no longer inbusness i don't know were you would need to go to get the parts, maybe from summit or jegs. also the factory kick down braket is a pain the butt to find. your best bet is to try to find a truck that had a 700R4 in it and try to rob the braket off of that. your carb might also need the tab were the tv cable hoks up to the carb.

[TwinTurbo]

I agree with SanitysBane, I don't trust the knuckleheads at the tranny shop here either

[SanitysBane]

and once u've done one it just gets easyer with every one

[Russell]

Well, I picked the tranny up tonight (thanks Opper!!) and it looks to need a bit more work than initially anticipated -- I say this because the fluid is black, and smells very burnt...

So I need to decide if I want to do this myself, or not...

SanitysBane -- If I do this myself, can you help me out, like telling me what kind of tools I need (such as measuring calipers etc) I know I'll be rebuilding motors and trannies for the rest of my days, so I had midas well by all the little instruments right away... I don't wanna rebuild this thing just to have it die the next day...

My shop is getting overhauled right away, so dirt won't be a problem then (pressure washing the entire interior, then repainting it) I have a ton of space in the shop (enough room for three trucks side by side if we squeeze it tight) so that shouldn't be a problem either. I can have a digital camera with me to take pictures of stuff every single step of the way, and maybe produce a bit of a tutorial or something while I am at it...

I know, this may be above my head, but every single guy at the tranny shop did their first tranny at one point too, so I had midas well go ahead and do so now...

[Opper77]

Sorry if its more work than you wanted to do.. If its beyond repair you could use it for your ginea pig and rip it apart for learnings sake, and then move onto a more readily-rebuildable core.

Let me know if there's anyting I can do for you.

Opper

[Destructo]

Originally Posted by Russell

Hey fellas, on a scale of 1 - 10, how tough is it to rebuild a 700r4 tranny? I wanna beef it up a bit so it can take my 355 later on (300 - 350 hp, and 350 - 400 ft lbs of torque is what I am aiming for)

What all is involved with this, and do you think that a kid like myself could do it? The tranny I am getting worked when it was removed minus a bad front seal, but it has a lot of km on it, so I would like to rebuild it right away.

Also, I seem to have a longtail TH400 (if such a thing exists, just a heck of a lot longer than the four speed granny I have) so would I need to get a new driveshaft as well?

My father knows a guy who owns a transmission rebuild shop who would likely be able to get me fairly cheap parts for it, so I'm thinking it may be worth it..

I say 5, rebuilt my own and never rebuilt a tranny before and i'm going on 9k miles so far and flawless operation. Its not hard, you just need to keep it clean, do it right and have the proper tools. I was 18 when I rebuilt mine (19 now) and it wasn't too hard, just be sure to get a good kit and check EVERYTHING, tear down the pump, check all the clearance, check the valve body for warpage and all that type of little stuff some people forget about.