A727 Diagnosis requested..

Well, so far, from what I read, I should do everything from, Ignore it and keep driving to, HOLYF%#@ don't even leave the driveway or a landmine will explode ripping all my limbs off.

Yes, "HELP" :D

Ya gotta get it to a trustworthy transmission shop, so they can pull the pan and see what is going on. I still think its just a band adjustment.
 
The kickdown band is adjusted from outside the case. You just want to make sure you don't "snug" it too tightly because that can move the servo really easilly. The low/reverse band you have to drop the pan, and it's a smaller wrench for the lock nut. Otherwise same process. I would also pull the valve body off (I think it's 17 bolts) and drop that out of the way (let it hang by the park pawl) and look carefully at the back of the geartrain. The low/reverse band covers most of the area the sprgue is enclosed in. But you might be able to see something.
 
The kickdown band is adjusted from outside the case. You just want to make sure you don't "snug" it too tightly because that can move the servo really easilly. The low/reverse band you have to drop the pan, and it's a smaller wrench for the lock nut. Otherwise same process. I would also pull the valve body off (I think it's 17 bolts) and drop that out of the way (let it hang by the park pawl) and look carefully at the back of the geartrain. The low/reverse band covers most of the area the sprgue is enclosed in. But you might be able to see something.
Thank you. That, plus the book by my side, I'll give that a shot next time I get her up on the lift.
 
If those little accordian springs are crushed flat or there anchors are bent you probably have a problem with the sprague. My bet is debris in valve body, governor, or servo, will most likely go away with use hence my ignore/drive till it quits. Unless you are doing abusive things to the trans ... In drive big smokey burnouts, Rockford files type J turns from reverse to drive, I doubt you broke the sprague.
 
It's not really hard in a heavy car to bend the spring retainers and flatten the springs in the sprague. I've rebuilt enough of them that I've found a couple that had the makings of a problem...
But you're right - in order to rip the sprague off you need to launch at 3K and hit the nitrous and not spin the tires...lol. It is, however, really fun.
 
It's not really hard in a heavy car to bend the spring retainers and flatten the springs in the sprague. I've rebuilt enough of them that I've found a couple that had the makings of a problem...
But you're right - in order to rip the sprague off you need to launch at 3K and hit the nitrous and not spin the tires...lol. It is, however, really fun.

I dunno. . . Stan always impressed me as a banzai kinda guy. . .
 
Although I could see Stan leaving somewhere in his rant kind of way reverse J turn if there are too many the other customers are on the trashy side. Just wish I could be there to see it or better yet riding shotgun. LOL
 
I've read a lot of "what if's" regarding your dilemma but I don't think that's what your looking to resolve your issue. I would recommend ( short of a complete rebuild ) that a man of your talents jack the car, remove the fluid and pan, remove the shift body and have a peak inside. There are many who believe redoing a tranny is "black magic" but honestly with a bit of knowledge on what to look for your toaster is probably more complicated. Here is a link to a multi-part series on You Tube that, if followed, any one can do what some have paid a fortune for. Follow it through and you may end up being as knowledgeable as the tech rebuilding it. Without a doubt you will know what to look for as he explains the inner workings of the 727 transmission and how to set it up. Do not waste time trying to disassemble and reassemble the valve body - many have tried and many have failed as all those small balls fall to the floor. If you feel this is the issue buy a complete TCI unit which is vastly superior to the original. To speculate on the cause of your particular issue would be like trying to guess how fast a turd drops on the space station, but once you delve into it personally you'll know. Think of all the satisfaction you'll feel by resolving this problem yourself - it'll be like 17 all over again. Besides, if you F&$k it up the tranny shop will still be there. Who knows, could end up saving yourself hundreds of dollars for a bit of your personal time.

https://www.youtube.com/watch?v=xzJhCBZ1wMY&list=PLA9698F0D2698CD77
 
600 horse power. It is a good video series he just likes to let you know he going to have 600 horse power. I rebuilt the trans in my wife's trailblazer watching you tube videos. When I broke one of the nylon sealing rings the guy at the trans shop bailed me out for $10 and unbolted the bell housing with the funny GM bit.
 
Hey Stan, here's a trick you can try between cocktails. Add 1/2 a pint or so of brake fluid to your trans. and drive it awhile. It will soften up the seals some. I had a nearly new 79 300 that would do the same thing. The problem was that the material of the seals was changed and they didn't seal well at low pressure when cold. The rear clutch piston seal would loose the seal to the drum until the pressure would rise with rpm. If the trans is "old" you may have a weak pump too. I have a 2000 Dakota that wouldn't make the 2-3 shift in winter until it was driven 4-5 miles, same fix worked on that.
 
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Just keep an eye on it. The chances of it exploding the drum are pretty slim if you never drop the hammer from a light in D. If you have the shifter in 1 then the rear band is applied as well as the overrunning clutch. In D the only thing holding is the sprag.

Contrary to what some think, the explosion isn't related to horsepower, it's strictly a function of RPM. Engine RPM X 2.45 is what it will spin the drum to.

Kevin

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