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Discussion Starter · #1 ·
Hi there!
I just finished rebuilding a 700r4 transmission and I'm having a problem. The trans is a '84 model out of a 4x4 truck, don't know if it was working before I took it apart and I rebuilt it just because I needed to swap the output shaft to install it in a car. I changed all the frictions, seals and gaskets and used the ATRA manual as a guide. I have rebuilt several Powerglides, th350 and th400 without any trouble yet but this time I'm out of luck. This 700r4 works good in first and reverse but the rest of the gears just dont work. With the shifter in D it remains in low and does not shift at any speed. I tried to shift manually but it doesn't work either. The TV cable has an initial set , the TV plunger is not locked, it slides freely and the spring moves it back and the centrifugal governor does not show any problem either. The gear is in perfect shape and the plunger moves freely. During the rebuilt procces I didn't see any obvious problem and there wasn't anything strange in the oil pan. So, before I take the trans out of the car (big PITA) I'm looking for some opinions here. Any clue where I should aim at? I guess I will be taking out the valvebody to check it but any input from experienced people is apreciated.

Thanks in advance!
 

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1949 Ford Coupe RESURRECTION
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I feel your pain.... First off, if there were no mistakes on your drivetrain portion of the rebuild, then to minimize the "trouble" of taking it out, There are a few things to address while it's still in the car. But I'd have a question or two.. when you rebuilt it, are you SURE that you got the checkballs back in the correct locations? Did you adjust the band correctly? It should only have no more than about 1/8" travel driven by the 2-4 servo. That can be checked by taking the cover off the 2-4 and push the "4" piston / pin in, with a micrometer mounted on the pin the check the travel. Did you do any air pressure tests before final assembly to assure that the clutches are being applied? I don't know everything there is to know, but I have learned about 100 things about them .... so part of this is just guessing. Did you check all the valve body valves move freely? Also, get a 300 psi pressure gauge and check your pressures...

This video doesn't make sense to me, but surely he's being factual... seems his TV valve stuck wide open or something like that......This may not be it, but ................https://www.youtube.com/watch?v=e4PXNrMy11U

In a nutshell, to save yourself from grief, you can do a number of things without taking it out, including taking the valvebody out (that's the LAST thing you want to do due to the difficulty of getting the checkballs back in (with some heavy grease to stick them where they should go)...

Here's my saga... Chapter 1

And Chapter 2

I used this guy's videos to guide me on my Chapter 2 rebuild.. the video is for a 4L60 E but the drivetrains are the same...

The guy who knows EVERYTHING about 700R4's is Dana at ProBuilt Transmissions... if all else fails.. he's very helpful in sharing his knowledge !

Keep us posted ! ! !
 

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Discussion Starter · #3 ·
Hi '49!
I'm pretty sure the drivetrain part is correctly assembled (fingers crossed). I installed the checkballs in their previous location (took a photo when dissasembled) and it matched the locations shown in the manual. I remember all the plungers in the valve body looked good and moved freely. Regarding the band adjustment I didn't really remebered doing that step, so I checked the procedure and I can tell you I didn't do it. Why? I don't know. Probably because I didn't have the tool at the moment or maybe just because I'm an idiot! In any case I didn't do my homework so I will start with that. I will have to take the tans out since the tunnel is just too tight. Anyway, with the trans out I will recheck the valve body and everything else. Will look at your links so I learn something positive out of this little tragedy.
Thanks a lot sir!
 

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1949 Ford Coupe RESURRECTION
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Before you take it out, consider cutting out the floor / tunnel ....... ! ! !! That's what I did...

this is page 2 of Chapter 2
 

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1949 Ford Coupe RESURRECTION
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Well.. you are a better man than me.........but I'm 77 ..... in any case, go ahead and get a Sonnax 2-4 COMPLETE servo kit and a 0.500 pressure control valve that goes into the bottom of the pump.. And like that guy said in the video, see if your TV cable connector/internally is sticking ....

I'm wondering what you meant by "it engages perfectly" ??????? The governor?

You are in Uruguay ??
 

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Discussion Starter · #9 ·
No way sir! I did a very ugly hole in the other side of the tunnel and was ready to make a bigger one in this side, but the 2-4 servo is in a very inconvenient place even to cut around. I'm 42 and have a good share of that kind of work!
Yes, the governor engages perfectly in the output shaft I swaped. ,I was answering to the previous post before seen yours. Sorry about that!
And yes, I'm in Uruguay. Very close to the ass of the world.
 

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Discussion Starter · #12 ·
Well, I finally found something suspicious thanks to you '49 Ford! The 2-4 servo pin is the longer one and it only left little more than 2mm of travel. I changed the band but didn't check clearances. What an idiot! Learning every day I guess. I just grinded it and now it has little more than 6mm (1/4"). Will get it together and report results. Thanks a lot to all of you!
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1949 Ford Coupe RESURRECTION
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Generally, the problem caused by the wrong pin length is that it's too short, meaning that the band may not hold, and being too long the band might burn up due to it not disengaging. 0.25" is about the limit of "too loose"......but in any case, I'm not so sure that would have caused the problem.... but I don't know everything, ya know...
 

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1949 Ford Coupe RESURRECTION
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before you do that, call Dana at Probuilt.... "phone or text 909 435-5360 or call 909 795-1876 "

a major deal, also is checking pump pressure.. do that before you take anything apart
 

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Discussion Starter · #16 ·
Boring saturday, so I took the tranny off. Again. At least its getting easier every time! I don't have a pressure gauge here but will get one on monday. In the mean time will check valve body.
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What do you think about the position of the checkballs? They're in the same spot they were when I bought it but again, Im not sure this was working right or working at all.
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1949 Ford Coupe RESURRECTION
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Watch all these and view the pictures... something seems funny with that one check ball location on the upper right of the second picture. I'm thinkin' that hole next to the check ball location is WAAAAY too big.. does it look like it's been drilled out??? I'm sure you are already pulling ALL the valves and springs in the valve body to assure nothing is stuck... and also your T/V and the detent.... and since you have it out, order that dang Sonnax 0.500 pump pressure valve. it's a ***** to get out in the car... (see my special tool I made to make it easy on my website)...

AND look for worn holes in the divider plate, but I'm sure you have already done that....

UPDATE: also get a pair of Sonnax accumulator pistons while you have it open and remove the old ones that have the rod in the center..

As a matter of fact, may as well go here and do some shopping for all sorts of things that will help performance:


Check ball information
 

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Discussion Starter · #19 ·
None of the holes look modified, all seems fine there.

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Of course '49 ford, checking every valve in this freaking valvebody! Nothing stuck or strange so far.
Thanks for the input guys.
Will keep posting results.
 
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