727 trouble ?

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Pernzee

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I have a 69 dart swinger with the 727 transmission. I'm getting a grinding sound and slipping out of the tranny in first gear. It only happens off the start when I accelerate harder. A gentle acceleration shows no problems and all other shifts are fine. Do I need some kind of adjustment?
 
What does it do if you start off in Manual LOW?
 
I just recently bought the car so I haven't touched anything yet. I know that the previous owner put an edlebrock carb on the engine and he mentioned that the kick down lever is at full extension. Is this what you are talking about?
 
Start with the simple checks first, fluid level and oil color? Bright red? Is the throttle linkage (kick down linkage) hooked up to the carb linkage? If so does the throttle linkage stop when you have the throttle pushed to the wide open position? The throttle linkage should stop when the carb is @ full throttle, meaning no more movement should be available in the throttle linkage.
How does it shift under light load applications as far as harshness and RPM level? How does it shift under heavy throttle applications?
The grinding noise along with the slipping does not sound promising, there are two band adjustments on a 727, one is an external adjustment and the other band is adjusted after you drop the oil pan.
My biggest concern is the grinding, worn out band or friction discs in one of the clutches.
 
Fluid level and color is all good, I'll have to look over the kick down linkages but all shifts are nice and crisp under light and heavy load. The car still kicks down and accelerates with no problems. Only getting the noise and slippage off the start with medium to hard acceleration in first gear. The grinding sound is kinda sounds like when your TV loses signal and you get that static sound. I guess I'll see about getting the bands adjusted first. What kind of $ can a tranny rebuild cost me if in fact thats what I'll need.

Thanks for all the replies !!!
 
Does not use a band in low. In manual low the band is on for down **** and reverse use. If you put it in L or R and stand on it what happens? Sounds like a leaking servo piston for low reverse or a forward stack is slipping. Only other issues could be a vavle stuck causing very low pressure of low?
 
ok well I didn't try standing on it in reverse but I put the car in manual low and it did the same thing off the start as it does in D. It seems like if I get the car rolling I can get on it pretty hard in first without the noise, its just right off the start (from a stand still) that it does this if I hit the gas too hard.
 
Pernzee said:
ok well I didn't try standing on it in reverse but I put the car in manual low and it did the same thing off the start as it does in D. It seems like if I get the car rolling I can get on it pretty hard in first without the noise, its just right off the start (from a stand still) that it does this if I hit the gas too hard.
Click to expand...


Drop the tranny pan and look for any metal filings. It sounds like a rear sprag failure. If not, it's always good to change the tranny fluid and filter.

kenny b
 
You know this is really off base here but could it just be a broken motor mount??? A broken motor mount will let the engine rise up on the drivers side and allow the fan to hit the shroud. That could be the grinding noise. I'd have a budy stand to the side with the hood open and you put it in drive and torque it up with the brakes locked on and your bud should be able to see if the engine tilts upward.
 
The previous owner did have the engine out last winter ! And I somewhat do remember him saying that he reused the old mounts. You would think that he would have made sure that the mounts were good but you never know I guess. I like your angle! I'll check the fan shroud to see if I can see and scuff marks too. It just seems strange that it only happens when I jump the car like your saying. And I can't say for sure that its 'slipping' , because I'm off the gas as soon as I get that noise anyways.

Thanks again for all the great advice, I'll update results :)
 
Yup ! Its an engine mount! I did a brake torque and the engine shot up like crazy and the fan hit the shroud. I'm so happy that it wasn't the tranny! :) Now I have to find out which mount it is. Any guidance on motor mounts? How to replace? Where and what kind to get?

thanks
 
Man I had that happen so many times when I was a kid that I could've probably changed motor mounts in the dark.

The drivers side is the one that breaks usually but both can be broken. The drivers side is the one that lifts up when you torque it up in drive. The pass. side is the one that lifts up when you torque it up in reverse.

As far as where to get one. That's the $50,000,000 question. There's stock ones that eventually break. Schumaker makes an unbreakable interlocking rubber type but it's pretty pricey. I think about $150. There's also solid mounts that are unbreakable but don't cost alot from Summit. I never used one but hear varying reports on them. Some guys say theirs don't vibrate and other guys say theirs does. I road in a early 70's Cuda with them and it sure vibrated alot. There's also torque bars/straps but I hear they wear out often. Or you could allways fabricate something up yourself if you have the tools.
 
Got some mounts coming in tomorrow!

Thanks for everyones help !

Pernzee
 
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