700r4 not shifting right - WTF?

[HotRodPC]

More line pressure will also blow seals. I have a feeling the 3-4 pack had been overheated before, hardened the seals, sythetic fluid being to thin, leaked past the seals. IF you haven't let it slip much, or overheat even more, a trans conditioner additive as much as I hate to suggest it, might just swell those seals enough that that they will work again. Its worth a try, or another secret I hate to suggest, with nothing to lose, try a pint of brake flluid. But, warning you know, brake fluid is harsh on the clutches, but it WILL swell the seals. IF the clutches aren't junked up yet, and just the seals are cooked a bit, the brake fluid will soften and swell them up. DO NOT use more than a pint. IT will either do the trick or it won't. But honestly, if it comes to the brake fluid trick and it works, its just a band aid and the trans is short lived. I'd say check the goveernor, but when you suggest, it acts like when it goes into the 3rd, it just starts to freewheel or slip, its not the governor. IF it wasn't trying to go into rd at all, then yes I'd think governor. TV cable or wrong elecrical wiring would have been your only hope of a fix IMO. Does the pan have a drain plug? Drain out the synthetic and put in Dextron/Mercon. Systhetic is only for GOOD, almost new transmissions, or KNOWN very well good condition transmissions. I've never been a big fan of synthetic fluid anyway. Not in an auto trans. Auto Trans fluid is good **** as is, and there really isn't alot of friction in an auto trans, not like rings scrubbing a cylinders walls or babbit metal crank bearings. Thrust washers and torrington bearings are slow wearing as it is. Keep them cool and clean and they can last just the same as Synthetic fluid kept cool and clean.

 

[HotRodPC]

PS Sorry for all the typo's My wireless keyboard is fuggin up, my internet connection sucks and it takes for ever for the edit wondow to come up so gonna have to live with my ****** posts for a few days.

 

[oneluckypops]

I cant see the TV cable having anything todo with is. SO LONG as it is hooked in the Transmission and at the carb, also adjusted correctly. The length of it should not matter aslong as its adjusted correctly.

 

[Jims86]

I cant see the TV cable having anything todo with is. SO LONG as it is hooked in the Transmission and at the carb, also adjusted correctly. The length of it should not matter aslong as its adjusted correctly.

the physical length of the cable is fine, we are just saying shorten, meaning adjust tighter, and vise versa.
My cable ends up a few clicks tighter than base setting...i dont like shifts to stack up. driving like an old man, mine shifts into 3rd at around 23-24mph.

 

[HotRodPC]

I cant see the TV cable having anything todo with is. SO LONG as it is hooked in the Transmission and at the carb, also adjusted correctly. The length of it should not matter aslong as its adjusted correctly.

You're right, and the KEY is, SO LONG AS ITS ADJUSTED CORRECTLY, and to make sure its not having to much pull on the TV valve keeping the trans in passing gear and not allowing it to get into 3rd. But, that isn't the case anyway,It obvously tries to go into 3rd and spins up with no 3-4 clutch compression. The trans would have auto all features wo TV cable, and wo electrical connections for luck up, just not right and not at coreected pressures and shift points. But it is a method of diagnosis. IF with cable and electrical disconnected and it didn't have shift, then its the governor. But I knew it wasn't that cuz he got 1-2 shift. I was hoping he'd disconnect cable and electrical, then at least get 3rd adn 4th. Didn't happen so its the 3/4 clutch pack not being compressed. Probably cuz of previously overheated seals and using thin synthetic fluid. IF he hasn't done any more damage to the trans trying, he may be able to pull out MOST of the synthetic fluid, add Dextron/Mercon and an additive to help swell worn seals, he might get some miles out of it. IF its burnt 3-4 clutch pack, its toast and nothing to fix that.

 

[oneluckypops]

You're right, and the KEY is, SO LONG AS ITS ADJUSTED CORRECTLY, and to make sure its not having to much pull on the TV valve keeping the trans in passing gear and not allowing it to get into 3rd. But, that isn't the case anyway,It obvously tries to go into 3rd and spins up with no 3-4 clutch compression. The trans would have auto all features wo TV cable, and wo electrical connections for luck up, just not right and not at coreected pressures and shift points. But it is a method of diagnosis. IF with cable and electrical disconnected and it didn't have shift, then its the governor. But I knew it wasn't that cuz he got 1-2 shift. I was hoping he'd disconnect cable and electrical, then at least get 3rd adn 4th. Didn't happen so its the 3/4 clutch pack not being compressed. Probably cuz of previously overheated seals and using thin synthetic fluid. IF he hasn't done any more damage to the trans trying, he may be able to pull out MOST of the synthetic fluid, add Dextron/Mercon and an additive to help swell worn seals, he might get some miles out of it. IF its burnt 3-4 clutch pack, its toast and nothing to fix that.

only thing that concerns me after reading one of his posts is. He said it does it right BEFORE it tries to shift to 3rd.

 

[Dieselshine]

What about maybe trying a Corvette shift servo??? With the fluid change and additive added might help, I've always had good luck with the 700r4's its always the Turbo 350/400 giving me troubles

 

[HotRodPC]

What about maybe trying a Corvette shift servo??? With the fluid change and additive added might help, I've always had good luck with the 700r4's its always the Turbo 350/400 giving me troubles

All a vette servo does is firm up a 1-2 shift. That wouldn't help this in the least.

 

[Dieselshine]

All a vette servo does is firm up a 1-2 shift. That wouldn't help this in the least.

Ahhh Ic I thought it firmed up all the shifts that's why I'm still grasshoppa lol

 

[HotRodPC]

only thing that concerns me after reading one of his posts is. He said it does it right BEFORE it tries to shift to 3rd.

Yep, so he's feeling the clutches that apply 2nd release then about the time 3-4 clutch pack should be applying it spins up cuz they aren't applying. I think its more of seal issue at this point, although the 3-4 cluttches are worn too. I only say that cuz he said he test drove it before buying it and it was all good. And it probably was. The synthetic fluid is the problem IMO. But, the trans would have been short lived even with Dextron/Mercon cuz the 3-4 pack was ailing but still functional. Could have lasted a week, might have lasted 6 months, no telling. He still has the best 700r4 core though. 88 up are the better ones with the aux valve body and more updated hard parts. Rebuild it with Alto pack or Z pack, Vette Servo, good cooler, and then the symthetic fluid. he'd be good to go for a long time.

 

[oneluckypops]

Yep, so he's feeling the clutches that apply 2nd release then about the time 3-4 clutch pack should be applying it spins up cuz they aren't applying. I think its more of seal issue at this point, although the 3-4 cluttches are worn too. I only say that cuz he said he test drove it before buying it and it was all good. And it probably was. The synthetic fluid is the problem IMO. But, the trans would have been short lived even with Dextron/Mercon cuz the 3-4 pack was ailing but still functional. Could have lasted a week, might have lasted 6 months, no telling. He still has the best 700r4 core though. 88 up are the better ones with the aux valve body and more updated hard parts. Rebuild it with Alto pack or Z pack, Vette Servo, good cooler, and then the symthetic fluid. he'd be good to go for a long time.

no offense to Jim or anyone else for that matter but, **** synthetic stick with Dexron III. We or atleast I have used it in all my gm rebuilds and it hasnt caused me any problems thus far.

 

[davbell22602]

So can synthetic fluids cause this same problem on a electronic shift transmission too?

 

[HotRodPC]

no offense to Jim or anyone else for that matter but, **** synthetic stick with Dexron III. We or atleast I have used it in all my gm rebuilds and it hasnt caused me any problems thus far.

I have no problem using synthetic T fluid, but I don't think its needed at all, and I don't think it will add life to an auto trans. For those who want to use synthetic, I"d only use it on NEW or very low mileage transmission. Past that, I'd avoid it. And if you don't know the history of the trasn, forget it, don't use it. Auto Trans fluid already has good lube properties along with detergents etc, no need for overkill and going synthetic.
NOW, those Tcases and Manual transmissions that require Auto trans fluid, I'd be all for synthetic fluid and I think there would be a beneft there.

So can synthetic fluids cause this same problem on a electronic shift transmission too?

Hell yes, it will affect E transmissions just the same as non E. The problem with Retro's trans, is that fact it was ailing, and the thiner slicker fluid is leaking past the overheated hardened seals and also the worn clutches it needs to compress the piston even further and just can't do it.

 

[davbell22602]

Hell yes, it will affect E transmissions just the same as non E. The problem with Retro's trans, is that fact it was ailing, and the thiner slicker fluid is leaking past the overheated hardened seals and also the worn clutches it needs to compress the piston even further and just can't do it.

Ok thanks.

 

[towman]

getting off topic here but my olds has a turbo 350, after rebuild put syn in it and the shift kit didn't work worth a ****, flushed it out and put dex back in it and shift kit will snap your neck going into second