700r4 problems

[iamtherealJayy]

So I know I know I have too many clunkers. I just picked up this 1990 K5 blazer with the very powerful 350 TBI and the 700r4 and the unicorn 241 with electric vss. I got this for a steal because previous owner stated trans was rebuilt and won’t shift to second. Now I don’t know a whole lot about automatics so I have spent the time since I got it home until now researching. I pulled the governor out, it flops around seems to move around with ease, the gear on the end looked fine(this is what was claimed to be the issue so I ordered the gear on the way home) it appears to have a new TV cable and I guess it’s adjusted properly? It doesn’t sag down from the distance from the throttle body to the holder. Now, I haven’t actually driven this truck more than around the yard moving it in fear I don’t wanna burn up the trans. It has been atleast removed and separated from the tcase since there’s fresh blue silicone instead of a gasket. The fluid was low when I got it, I added probably 2.5qt of dex III to it. What could the issue be? How harmful could a test drive be? I don’t want to completely trash the trans if it’s salvageable currently. I really don’t want to replace it either since I can’t find a 4x4 700r4 within four hours of me. The fluid is a bright pinkish color, not dark, smells fine I suppose?
Edit: by not shifting to second I mean he claimed it just wouldn’t shift at all not that it skips second. I put it in D to move it, I haven’t had the truck above 12 or so mph

 

[squaredeal91]

Being 2 1/2 qts low could do it. If it were me I'd try to drive it. Or at least jack it up and power brake it a little to see if it shifts in the air without a load

 

[iamtherealJayy]

Will the shifts through gears be obvious without a load? I’ve got plenty of stuff I can support it in the air with and let it get up to speed. I just haven’t wanted to further damage it if preventable. I mean I got it for a steal so if I have to spend a couple hundred on a trans it isn’t the end of the world but I am trying to make this one a daily, my other blazer didn’t fit the description enough.
Edit: also while I was under there I didn’t see any obvious fluid leaks, so it might’ve just been low after the rebuild. Good? Probably not. Also is there a bushing or something that goes in the gear selector rod where it meets the frame? My rod just kinda jiggles in there, I suppose replacing that could help the shift indicator lineup better? It’s more between the letters the farther down you shift. First is more on the 2 than the 1.

 

[gmbellew]

TV cable is pretty easy to check. just reset it and pull the throttle linkage to full throttle at the TBI to get the tension right.

be sure to check fluid levels with the engine running.

if fluid and TV cable are right, I'd say take it for a spin and see what you have.

if you are really nervous, drop the pan first and see what the fluid/filter looks like and if there are parts floating around...

 

[squaredeal91]

If speedo works it will be obvious. Otherwise you should feel it in the brake pedal if you're braking a little. And I usually do it with the door open so I can watch the tires.

 

[squaredeal91]

I forgot to add that I also like to try dropping it into 1st and manually shift it through the gears.

 

[iamtherealJayy]

@gmbellew when I got it the cable had a little sag so I went through the procedure for adjusting, pushed it all the way in and held wot but then I pushed it back in a couple clicks so it wouldn’t sag, I don’t know what kinda cable it is but it’s got a bajillion feet extra past the clip part.
Would taking it for a spin ruin anything that hasn’t been already? I need to button up some other things before it’s really road worthy but I have probably an eighth mile or so of straight I can play on. I still gotta get an o2 sensor since someone put headers on it and never put the o2 in.

 

[gmbellew]

cable shouldn't be lose after proper adjustment. wonder if somebody messed with the bracket geometry? is it the factory TBI unit? or has the wrong cable on it?

 

[iamtherealJayy]

It’s still got a throttle body and what appears to be the factory bracketry. I believe the cable has been replaced, possible after it was “rebuilt”?

 

[Matt69olds]

Will it back up? If not, I bet you will find it has no overdrive either. If you have no reverse, 2nd, or 4th, most likely the drive shell is broken. Fairly common issue. The Sonnax drive shell is about 125 bucks. It does require transmission removal, and almost complete disassembly. However, if that’s the only issue, no need for a complete overhaul assuming the rest of the trans is good.

Put the shifter in first, gently accelerate to 25-30mph, put the shifter in 2nd, then third. If it goes into 2, most likely the tv cable is out of adjustment. If it has no 2nd but goes to 3rd, most likely there is a band or servo issue.

If it won’t shift period, remove the govenor again. Wedge some rubber hose between the governor weights and gov shaft. Reinstall the govenor, you just made a poor man’s manual valve body. With the weights mechanically held out like that, as far as the trans is concerned you are driving 100 mph. Gently drive it again,see if it will shift with maxed out Gov pressure.

Still nothing? Could be stuck shift valve,

 

[iamtherealJayy]

@Matt69olds i have park reverse neutral and atleast one forward gear, I haven’t gone fast enough for a shift yet. I was just told it didn’t shift after a rebuild. I saw cheap K5 blazer, running somewhat driving, so I snagged on it. I can try the governor trick, I haven’t heard that one yet lol. I was told by previous owner from their “research” it had to be the governor gear. I ordered a new one on the way home, went to replace it got trans fluid all over my arm just to find the governor gear was intact, little wear but still perfect teeth. Governor weights moved freely and the inner valve went up and down.
Say putting that rubber in there and going for a drive, would I manually shift or put it in drive? I’ll try to limp it for a test drive sometime tomorrow if I get a chance.

 

[Matt69olds]

In theory it should go to first in fist gear and shift as you move the lever. I’ll be honest, I have never tried it in a 700. I have done several poor man manual valve body’s with 350/400 transmissions, so the theory is sound.

I’d try to drive it a little aggressively, and see if it will eventually shift or skip 2nd gear.

 

[rusted nuts]

Yeah, If

In theory it should go to first in fist gear and shift as you move the lever. I’ll be honest, I have never tried it in a 700. I have done several poor man manual valve body’s with 350/400 transmissions, so the theory is sound.

I’d try to drive it a little aggressively, and see if it will eventually shift or skip 2nd gear.

Yeah, Need to drive it like You would if it was shifting like it should. If You drive it easy it won't act like it should and You will things are wrong.

 

[iamtherealJayy]

I’ll try and get around to going for a test drive. Just now getting home today, so not happening today. I can drive it like I stole it and something will definitely happen, hopefully just a hard shift lol then I’ll know this trans is fine

 

[iamtherealJayy]

I went and checked the trans fluid esrlier, cold, been sitting a few days, and it’s way high? Start the truck wait a few minutes and it’s a little high, maybe a pint according to the “add 1 pint” to “full” range. Is fluid being way over full cold a bad sign or normal?