727 issue NEED HELP
#1451223
06/11/13 12:29 PM
06/11/13 12:29 PM
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Joined: Jan 2003
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JERSEY
RJS
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JERSEY
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The automatic in my GTX does this one last hiccup that I need help with. I got all the linkage correct for shifting and kickdown at cruise speed and WOT. The only thing that happens sometimes is if you put it in Drive from a stop it will bump fully in when you hit the gas. You can drive a million miles without this happening until you take it out of drive and put it back in from a stop. I'm thinking line pressure because I haven't had that checked but would like to hear from someone that really knows. Trans is stock no kit in it and the fluid and filter have been changed too. Thanks Ron 
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Re: 727 issue NEED HELP
[Re: RJS]
#1451225
06/11/13 12:50 PM
06/11/13 12:50 PM
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Joined: Oct 2012
Posts: 1,106
Northeast
VincentVega
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super stock
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any possibility it is not the trans? strut rod bushings? tailshaft mount? axle backlash? Ujoints?
maybe the gear selector linkage is not quite right?
how many miles on the trans? did it ever run with water in the trans oil? I had a 727 where the radiator cooler contaminated the trans oil. it obliterated the clutch material
Looking for 1975 through 1978 B body 4 door sedan sheet metal or parts cars - monaco, fury, coronet. Please let me know
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Re: 727 issue NEED HELP
[Re: RJS]
#1451227
06/11/13 01:02 PM
06/11/13 01:02 PM
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Posts: 3,675
Akron, Ohio U.S.A.
roadhazard
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master
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I have this same issue with my Charger and posted here looking for help. From what I remember was told the forward clutch seal rings were bad. Hope to get mine gone through this summer 
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Re: 727 issue NEED HELP
[Re: RJS]
#1451228
06/11/13 01:03 PM
06/11/13 01:03 PM
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Joined: Oct 2012
Posts: 1,106
Northeast
VincentVega
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Oh, that would explain it then. probably a bad rebuild. Does sound like it could be line pressure, it could be bleeding off pressure inside or be maladjusted somehow, it could just be an incorrect assembly. Trans are pretty tricky and it's easy to do it wrong even if you are careful. Had a lockup 904 that absolutely hated going into reverse after a third party rebuild. It would do it but it would make some really ugly noises (more so when cold, less so when hot).
Looking for 1975 through 1978 B body 4 door sedan sheet metal or parts cars - monaco, fury, coronet. Please let me know
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Re: 727 issue NEED HELP
[Re: RJS]
#1451230
06/11/13 01:15 PM
06/11/13 01:15 PM
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Joined: Apr 2006
Posts: 3,675
Akron, Ohio U.S.A.
roadhazard
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If it's the sealing rings no adjustment is going to take care of it  If I initially put mine in (D) I have to be easy accelerating initially until the forward clutch engages fully. Once engaged it drives just fine. If it is taken out of (D) and put into (N),(R) or (P) the process of being easy on the throttle initially until fully engaged starts all over again. I'm sure we have an expert on the board who will chime in.
Last edited by roadhazard; 06/11/13 01:15 PM.
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Re: 727 issue NEED HELP
[Re: RJS]
#1451231
06/11/13 01:15 PM
06/11/13 01:15 PM
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Joined: Oct 2012
Posts: 1,106
Northeast
VincentVega
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If you don't mind paying to have a professional take a look at it, then go for it. Maybe it is something simple. If it is not, sounds like there's still time to put it right without probably having to shell out for a new rebuild kit
Here is what the service manual suggests
Bad rear clutch
bad front clutch (lol)
bad reaction shaft support seal rings
idle speed too low
aerated fluid (that's a possiblity. was it overfilled? re-used filtered oil? added in a weird way?)
low fluid level
bad gearshift adjustment
Low/Reverse band or servo issue
valve body issue or leakage (warpage, overtightened)
hydraulic pressure too low
Looking for 1975 through 1978 B body 4 door sedan sheet metal or parts cars - monaco, fury, coronet. Please let me know
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Re: 727 issue NEED HELP
[Re: roadhazard]
#1451232
06/11/13 01:28 PM
06/11/13 01:28 PM
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JERSEY
RJS
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Quote:
If it's the sealing rings no adjustment is going to take care of it
If I initially put mine in (D) I have to be easy accelerating initially until the forward clutch engages fully. Once engaged it drives just fine.
If it is taken out of (D) and put into (N),(R) or (P) the process of being easy on the throttle initially until fully engaged starts all over again.
I'm sure we have an expert on the board who will chime in.
That's exactly what it's doing.
I wouldn't doubt internal problem since I've had to touch everything on this "done" car.
Is having line pressure checked an easy thing?
Band adjustment?
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Re: 727 issue NEED HELP
[Re: RJS]
#1451233
06/11/13 01:36 PM
06/11/13 01:36 PM
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Joined: Oct 2012
Posts: 1,106
Northeast
VincentVega
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super stock
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E-booger recently put out a tech letter response that goes into adjusting bands with nothing but driveshaft drag to fine tune it. you can take that one with a grain of salt. the real procedure calls for accurately testing the tightness of the adjuster, "backing off", etc etc.
as far as the pressure test, that's a bit of a bear. It looks like you're supposed to be able to drive the rear wheels (so: lift) and then do some tests with the pressure gauges attached to the ports. Not sure how easy that is, and you'd need the proper tools. probably a bit of a pain
Looking for 1975 through 1978 B body 4 door sedan sheet metal or parts cars - monaco, fury, coronet. Please let me know
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Re: 727 issue NEED HELP
[Re: VincentVega]
#1451234
06/11/13 02:16 PM
06/11/13 02:16 PM
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Joined: Jan 2003
Posts: 25,902
Rio Linda, CA
John_Kunkel
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Band adjustment has nothing to do with initial takeoff in Drive.
It does sound like a pressure problem at idle or leakage in the rear clutch circuit. Be absolutely sure the shift linkage is adjusted correctly; crawl under the car and check it in each gear.
The INTERNET, the MISinformation superhighway
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Re: 727 issue NEED HELP
[Re: John_Kunkel]
#1451235
06/11/13 02:37 PM
06/11/13 02:37 PM
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JERSEY
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Quote:
Band adjustment has nothing to do with initial takeoff in Drive.
It does sound like a pressure problem at idle or leakage in the rear clutch circuit. Be absolutely sure the shift linkage is adjusted correctly; crawl under the car and check it in each gear.
John thanks for chiming in also, shifter was checked and adjusted perfectly also.
I can on with this trans. forever because it does everything else right but would love to make 100% without a rebuild.
Ron
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Re: 727 issue NEED HELP
[Re: RJS]
#1451236
06/11/13 03:19 PM
06/11/13 03:19 PM
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U.S.S.A.
JohnRR
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Quote:
So I guess I could bring it by a local shop here and ask to have the line pressure checked/adjusted and check band adjustment??
The line pressure would have to be real low like something was hanging up for it to be fine once you got on the throttle?
The bands are not in play unless you shift to manual low, as soon as you put the shifter into drive the rear clutch should apply and the car should be in gear, convertor drainback is an issue with the 727. To see if that is your issue start the trans in neutral and let it idle for a couple of minutes to allow the convertor to fill, there is a small amount of cooler flow in park but it takes a long time for the convertor to fill. After the few minutes in neutral put it in drive and see if it does it.
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Re: 727 issue NEED HELP
[Re: roadhazard]
#1451237
06/11/13 03:27 PM
06/11/13 03:27 PM
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JohnRR
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Quote:
If it's the sealing rings no adjustment is going to take care of it
If I initially put mine in (D) I have to be easy accelerating initially until the forward clutch engages fully. Once engaged it drives just fine.
If it is taken out of (D) and put into (N),(R) or (P) the process of being easy on the throttle initially until fully engaged starts all over again.
I'm sure we have an expert on the board who will chime in.
The rear clutch is not fully engaging, you have a leak in the hyd. circuit , it's either the sealing rings, the area in the stator support where the rings seal or the seals in the rear piston retainer driving it like this is only going to burn up the clutch pack the more you drive it like that. I would think the trans is slipping some as you drive it?
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Re: 727 issue NEED HELP
[Re: JohnRR]
#1451238
06/11/13 03:35 PM
06/11/13 03:35 PM
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Joined: Apr 2006
Posts: 3,675
Akron, Ohio U.S.A.
roadhazard
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Quote:
Quote:
If it's the sealing rings no adjustment is going to take care of it
If I initially put mine in (D) I have to be easy accelerating initially until the forward clutch engages fully. Once engaged it drives just fine.
If it is taken out of (D) and put into (N),(R) or (P) the process of being easy on the throttle initially until fully engaged starts all over again.
I'm sure we have an expert on the board who will chime in.
The rear clutch is not fully engaging, you have a leak in the hyd. circuit , it's either the sealing rings, the area in the stator support where the rings seal or the seals in the rear piston retainer driving it like this is only going to burn up the clutch pack the more you drive it like that. I would think the trans is slipping some as you drive it?
Yes JohnRR you are correct! I miss spoke as it was told to me before it's a rear clutch issue NOT a front clutch 
Well it drives fine and have about 4,000 miles on it like that. Long trips when it gets real hot it seems a little mushy.
Beating on it at the track after about 4 passes it didn't seem too happy so I gave it a brake and quit for the evening
Again thank you, John Kunkel and others for chiming in on that 
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Re: 727 issue NEED HELP
[Re: roadhazard]
#1451239
06/11/13 08:42 PM
06/11/13 08:42 PM
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JERSEY
RJS
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I always pull the shifter into neutral when I start the car cold. I know about converter drainback from my racing days. This is more pronounced on a warm transmission not cold. So since this car is a cruiser and not one I race I guess there is a winter project waiting!!!
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