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700r4 weirdness

goathearder

goathearder

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Hey Guys,
I am having some weird shifting issues with my 700r4 and I don't know how to troubleshoot it. Boils down to 2 issues:

1) When I go WOT or close to from a standing stop the truck barely moves and it feels almost like its in neutral.

2) When I am accelerating and the truck is about to up shift the rpm jumps up like 1000 to 1500 first and then it up shifts. It's like it's downshifting first then up shifting. I.E. the rpm is at about 4000 and its about to shift but the rpm jumps to around 5500 first and then it up shifts.

I checked the tv cable and tightened it which seemed to have helped a little bit but its still doing it. Not sure what to check next and I don't think I can tighten the tv anymore.

Could it be the governor? Thanks for any help.
 
I need more info...

Does the slipping (that's what jumping rpm is) happen in all gears?
Always at WOT?

What happened RIGHT BEFORE this started?

If it does, then my ATSG Manual is showing that you have either:

A) Sticking TV Valve.
B) Stuck TV Exhaust ball.
C) Binding shift arm or linkage.
D) Oil pump or valve body faces not flat. (Warped)


Did you FULLY REMOVE your TV Cable to see if its broken or stretched?
You can check the Governor, and cross yer fingers.... But, this is what you should do:

1) make sure the TV is good.
2) drop the pan, and check the TV/Manual shift linkage.
3) if it ain't either of those, you'll need to drop the Valve Body to check TV valve condition.

This is where some of you guys get all: "Nope, get that witchcraft away from me!!!"
So, tread accordingly.
 
I think its happening in all gears. Not only at WOT but that is certainly when its the most pronounced and easily reproducible.

I cant think of anything out of the ordinary that happened before this. The truck was sitting for about 5 days but was fine when I drove it before that.

I did have some stuck valves in the valve body when I first installed the tranny so that could very well be the culprit.

I took the tv cable off the throttle body and pulled/snapped it and it snapped back just fine so I think the cable is ok???
 
I think there's been an influx in 700r4 threads, probably due to the fact that the oldest ones are now 30 years old, simply put it's a mass extinction.

Another possible trick is while engine running, to pull that tv cable and snap it a few times incase there's any debris in the throttle valve, it could dislodge. Wishful thinking though.

I think we need to create an 'all about the 700r4' sticky.
 
Yup, well ya figure the first ones came out in 82? Last in 90? So they're all between 20-30 years old. I'm sure no one did a fluid/filter change every 60k miles, hell I've been meaning to do mine since I bought it.

Just about time all it is. They're great transmissions, if taken care of and not screwed with, but time is time. I think there are a lot of people who don't know the difference with it's few quirks that ultimately lead to it's demise like bigger tires/lower rpm and tc lock-up (lock/unlock searching), changing carbs w/o getting a proper tv bracket, tv cable adjustment. Completely cleaning trans cooler/lines and torque converter with new install or after rebuild.

They're not bolt and go like 350s or 400s. Only reason I even know this stuff is because I've made ALL of those mistakes on a previous K5s.
 
mrschaeferpants said:
I think there's been an influx in 700r4 threads, probably due to the fact that the oldest ones are now 30 years old, simply put it's a mass extinction.

Another possible trick is while engine running, to pull that tv cable and snap it a few times incase there's any debris in the throttle valve, it could dislodge. Wishful thinking though.

I think we need to create an 'all about the 700r4' sticky.
Click to expand...

Oh dang, I snapped the cable but not with it running. I'll give that a try and see if it helps anything out.

If not, I guess I'll pull the valve body (ugh).

Anyone have experience with the TCI constant pressure valve body? Since I already had some stuck valve if I have more I am inclined to just change the valve body cause I have heard 700 valve bodies warp easily.
 
Have you pulled the pan and verified that the filter has not come loose from the pump or that the filter neck isn't cracked? Sounds to me like a low pressure/flud starvation issue. The constant pressure VB's require pump mods and servo be installed as well as the VB to keep the line pressure artificially high at all times. In my opinion you are better off with a good clean up and rebuild of the valve body you have unless you are planning additional mods to the trans or a full build.
 
Hey Greg, I haven't pulled the pan yet but I guess I have a project for this weekend. I'll drop that and make sure everything looks ok.

Anyway to tell if the TV is stuck without dropping the valve body? What about the TV exhaust ball? I remember putting that in when I had the valve body out last but is there a way to see if its stuck?
 
If someone can get the BIG MAN to okay it,
I'll upload the entire ATSG 700R4/4L60 manual.... :deal:

As long as its not for financial gain I don't see the problem? :dunno:
----------

And the short answer on 700's going bad, en masse.... Their CRAP.

The pre-'87 edition is CRAP, and the '87-up aint MUCH better.
Usually, when an 87-up bites the dust, some A-Hole will swap in a pre-87, to save money.
That goes BOOM even faster... :haha:

The pre-87, having already gone bad, has been "rebuilt", and has sat for YEARS.
Hence the "50k mile grenade" habit...

Oh and GM was on crack when they designed the thing.
It's an awful design inside.
The port sizes/lengths are retarded, the cases are cast badly, the soft parts were WAY too cheap,
The factory let some go out the door in terrible condition, the 2-3 shift design is bad,
The Sunshell is too flimsy for a Honda civic, nonetheless a 4x4. Etc., etc.
 
TheBeast_88K5 said:
And the short answer on 700's going bad, en masse.... Their CRAP.

The pre-'87 edition is CRAP, and the '87-up aint MUCH better.
Usually, when an 87-up bites the dust, some A-Hole will swap in a pre-87, to save money.
That goes BOOM even faster... :haha:
Click to expand...

I definitely knew this when I swapped it in place of the TH350 but I really needed overdrive (mines an 89 k case).

My plan was always to eventually replace it with a built 700Raptor. If built properly can they really handle the claimed power output (500HP on the stage 2)? After reading your last post I am concerned that even a built one will grenade on me. I am only running a 350hp motor and don't plan to go any bigger than that.
 
TheBeast_88K5 said:
If someone can get the BIG MAN to okay it,
I'll upload the entire ATSG 700R4/4L60 manual.... :deal:

As long as its not for financial gain I don't see the problem? :dunno:
----------
Click to expand...

If you email it to me? I'll host it and post a link back for you to share.
 
Update on this, now I'm even more confused. I went for a quick drive tonight to warm it up and tried the tv cable snap trick and that seemed to make it worse. Now it shifts waaaay later than normal (like 2500 rpm) at normal acceleration and from a dead start at normal acceleration it makes a clunking noise and slips for a second or two and then engages.

Ill pull the pan tomorrow and look but not really sure what to look for. Pointers?
 
goathearder said:
Update on this, now I'm even more confused. I went for a quick drive tonight to warm it up and tried the tv cable snap trick and that seemed to make it worse. Now it shifts waaaay later than normal (like 2500 rpm) at normal acceleration and from a dead start at normal acceleration it makes a clunking noise and slips for a second or two and then engages.

Ill pull the pan tomorrow and look but not really sure what to look for. Pointers?
Click to expand...

Bits or chunks of debris in the bottom of the pan for starters mixed with blackened red ATF and that burnt smell. :doah:
 
I should also mention that if I put the gear selector in 1 I get no clunking from take off.
 
Ok, got the pan pulled and think I found the culprit.

First off, the fluid was nice and red and aside from some black sludge (smooth with no discernable grain0 in the bottom of the pan the pan was clean too. No metal chunks or anything like that.

However, it looks like Greg had it right because the filter was not in it home! When I pulled the pan out, it was sitting in the bottom of the pan. This is actually the second time that's happened to me. The first time I thought I must have somehow knocked it loose removing the pan but I was super careful this time so there is no way I hit it.

Why would the filter keep falling out???

In addition, if you check out the attached pic, you can see something sticking out of a valve body bore right in front of where the filter goes. Nothing else sticks out of the valve body past flush like this piece so I am wondering if I am missing a roll pin to hold it in? I can push it back in the bore but it just springs back out to what you see in the pic. Could this thing be pushing out under pressure and knocking the filter out?

Hopefully this is something not too disasterous and can be fixed easily.

Valve Body.JPG
 
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