Driveway carnage... 700R4 help (1 Viewer)

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TheGr8Doughboy

TheGr8Doughboy

Joined
Oct 18, 2004
Threads
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Location
Rockville, MD
Not sure this is hardcore but I thought I'd find the highest concentration of Chevy parts here.

1988 700R4 worked well for maybe 100 shakedown miles. I did not replace the clutches or the bands as the tranny shop that was lookin over my shoulder said they all looked ok and my budget was TIGHT.

Blew the hose off of the tranny cooler coming up hill in second gear didn't realize for 50 meters or so untill the smoke was rolling out :doh: Lost 4-5 quarts of tranny fluid.

Replaced the fuild and ran the truck a few times to work the fluid through and the dipstick shows full. Problem: I have a lot of slipping in second gear. When it hits 3rd it jerks pretty hard even under 40% throttle. I feel like 1st and 3rd are working well, and I cannot say much about 4th gear as I have no shocks yet.

I'm afraid that I glazed or burned the 2-4 band and ruined my tranny that I just put in.... what's the verdict?

Thanks
Chris
 
I'd be inclined to flush and refill the trans and try again before I condemed the trans as junk. While you decide what to do save your pennies and scrap aluminum cans for a complete rebuild kit to do the job again if needed. I'd run it a little while and see if the band "heals" myself. Just play nice with it.

Nick
 
What would cause you to suggest flushing and refilling? The fluid is basically all new since it was purged out... right?

It seems to pull well in 4th gear though, I had it out last night driving around.

(sorry for the newbish question)
 
My thinking is that with fresh fluid and gentle driving you might be able to "unglaze" the 2-4 band. I'm also thinking you might have washed some crap into the wrong place that is causing the goofy shifting your seeing. I'm thinking flushing it might help with that sort of problem (or at least fresh fluid). Ok, enough thinking! ;)

I was able to limp along a 4L80E in my cube van that was weak in 4th by flushing and refilling. Worked great until I overloaded the van then towed a Cruiser from NJ to IN. Made it home but had no 4th or Reverse when I got there... But then I know little about how autos work and am more than likely talking out my behind... :rolleyes:

But in a similar experience: I had JUST installed a pro rebuilt 4L80E into my cube van (after the aforementioned road trip). Got a few miles up the road and noticed a cloud following the van and it was getting worse! Pulled of to the side of the road to find a cooling line had cracked where rust had weakened it. Got some rubber cooler line to patch it up on the side of the road, topped it up and returned home. After making new lines, installing a stacked plate cooler, refilling and leak checking...it's been fine.

I doubt you lost enough fluid and ran it long enough to do much damage to it. I still say run it and see what happens. It either works fine or it's gonna need some new parts.

Maybe a couple folks with REAL trans knowledge will drop some useful advice too. :D

Nick
 
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Haha, thanks for the advice... that makes enough sense to give it a shot. I think when I do that I'll stick some lucus in and see what happens then.

Chris
 
Maybe you could check the servos when you change the fluid, ive heard of swapping vette servos into 700R4s to get the 2-3 shift to firm up so there might be some kind of correlation between them and your problem. Maybe the heat of running it without enough fluid screwed up an o-ring or something.

God slushboxes suck sometimes......
 
I'm running the corvette servo right now and it shifts great. It's just not holding which is why I suspected the 2-4 band.

It the T.V. cable the only thing that controls how hard the band or clutches are holding?

I have too much other stuff to finish up this week to really fool with this so it'll make the run back to school (I'm planning to run down saturday in traffic so the interstate will be slow)

Chris

I'm still wanting those shackles if you still wanna swap stuff. Gimmie a call again my cell died and I lost all of my numbers.
 
The tv cable could definitly be an issue, the cable on my truck was sticking so that it would be either held wide open or shut, the truck wouldnt shift at all when it happened, either too much or too little line pressure. Are you using the self adjusting gm cable? That should be a 2 minute job to check if you are. Ive seen some slick cam adjustable tv cable brackets for drag cars so you can fine tune the shift firmness, but it should be fine as long as its tightened to spec.

Ill definitly give you a call when i come down to tech next time, i transferred to VCU to be with the fiance but ill be down often to chill with my buddies and such. Left an ass-ton of stuff at my apartment when i moved out too.
 
Also get a tranny temp guage. It may or may not of helped you in that situation, but is a small price for piece of mind.

Best of luck.
 
sounds like you smoked the band. if you did, then no additive or new fluid will fix it for ya. but it's easy enough to pull the front half of the guts back out of the unit and replace the band/clean up the drum with some 80 grit.

the band is responsible for 2nd and 4th so that makes sense.
 
The slipping continues to get worse :crybaby: bummer and I'm worried that I'll get to the trail and not being able to get the power to the wheels would suck.

Is there a way to pull the pump out of this tranny with out removing the valve body? I don't wanna do that part again.

Thanks
Chris
 
you don't have to pull the VB but you do have to pull the lockup solenoid. i would definetly not attempt to drive it thw ay it sits.
 
Thanks for the help so far... one more thing to sort out so I can get it to an exhaust shop and inspected. Kind of a cross post from the 60 series section but I'm not getting much help there.

I put lucas tranny fix in and 3rd gear dissappeared. It'll shift into 3rd gear just not enguage.

So out comes the whole tranny and replaced all of the clutchs and bands... back in... still no third gear.

My apartment complex says all vehicles have to be inspected... I gotta get this stupid truck going ASAP.

Please help
 
lucas tranny fix is snake oil, just like the rest of the additives promising to fix your transmission. if that crap worked, a lot of transmission shops would be out of business.........

did you rebuild it using an ATSG manual or an instructional video?
 
I used a Haynes manual. I'm a little worried about the clearance on the 3-4 foward clutches... I think they may be a little loose.

But how would adding Lucas... even if it's "snake oil" mess this thing up? I drove to work and put it in and work and on the drive home third gear was gone. I didn't look for problems on the rebuild I just assumed that having the Lucas out of the system would fix it. Now I need to know what to look for and if I can narrow down my troubles.

I'll buy and ATSG manual this evening.

Georg I owe you a beer for all of this help man
Chris
 
peel the inspection sticker off the g.f. car, and put it on yours...problem solved...

either that, or throw some antique plates on it and then it doesn't need to be inspected :)

bk
 
Why wouldnt it pass inspection with a messed up 3rd gear, they wont drive it.
 
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