Another 700r4 another problem

[silversnail86]

Ok, so I bought a rebuilt 700r4 off Craigslist, cost me 100. The guy who sold it to me said it was a 0 mile rebuild, looking under the pan he wasn't kidding, with corvette servo and a shift kit. So I go get the trans last night put it in today go for a test drive and it won't shift. I have reverse and 1st that was it. So I swapped governors ,with the fully functional one from my old trans, now it shifts but only when it wants to. Sometimes it should sometimes early sometimes late. No overdrive, shifts can be very harsh but aren't always. If I put it in maual 1 or 2 that's it no more shifting. When it doesn't shift and I let off the gas it just goes to neutral. It has shifting problems everywhere. BTW my pressure gauge sprung a leak so i can't check the pressure. But I checked while the pan was off and its set correctly. I just dropped the pan inspected the throttle valve and it moves flawlessly. Anyway any ideas

[kmfb]

is your TV cable adjusted properly at the carb? If its out of whack even a little it can cause the transmission to burn up very quickly. Wide open throttle and the cable should be pulled tight and set, idle it should have just a hair of slack. This is how I set mine and have had no problems.

[silversnail86]

i checked throttle valve movement with the pan off.

[kalbert]

Check that the pressure regulator valve was installed correctly, one that is sticking, stuck, or assembled wrong can cause a whole host of problems.

Good idea to use your original governor, there's a hundred different weight and spring combinations for those things. Chances of getting one at random that is calibrated the same is pretty much 0.

A $100 rebuilt unit sounds fishy. People have lots of different ideas for what "Rebuilt" is. Possibly it didn't work right so the guy put a cheapo B&M shift kit in it and a "Corvette" servo to try and "fix" it. When that didn't work he yanked it and sold it. Got his $100 investment back. Have you had it open further than the pan to see the condition of the clutches, seals, and bushings? Any info on what was actually done to rebuild it?

[silversnail86]

i've only had it apart to the seperater plate which was new. there wasn.t a spec of anything on the inside. and at the dipstick hole it had a plug like you would see from a shop or shipped trans i work at a lube shop so i drop trans pans all day and have never seen a clean one like this. if it had been run there would be some debris somewhere but theres not. Anyway i cleaned and inspected a handful of valves in the valvebody, just the ones i have diagrams for and i now have everything but 4th when i shift into O.D. it won't hold any gear when i let off the gas. 1-2 shift is soft at light throttle but VERY firm and positive at WOT 2-3 however is very harsh all the time even at light throttle its enough to rattle my dash. tomorrow I will take a look at the hole that goes to the servo for obstructions. the converter has a nice 2200 stall in it thats very helpful with my crappy 2.73s!!

[silversnail86]

Plus the guy also had a vortec motor with a new cam and pistons for $150 i saw the new cam and pistons and freshly machined block myself heads were decent.

[crazeetxn]

Did you swap if for another 700R4? Reason I ask is, just because the TV is moving doesn't mean the pressure is right. They have to be set initially at the carb then slightly adjusted from there. When I swapped a TH350 for mine, I had to buy the Holley carb adapter to hold it at the right angle.

[silversnail86]

yes i swapped for a 700 You can set your tv cable properly by making sure that when you are at full throttle the plunger is completely compressed. IT IS NOT THE TV CABLE PERIOD. have the adapter have the right cable is adjusted properly Not all 700r4 problems are caused by improper cable setting. I appriciate the input but that NOT the problem. Its not the t.v. valve as I've had it out and inspected it cleaned it and made sure no sticking.

Like I said I have all gears but 4TH . Please only reply if you know of something else I should look at.