727 Trans Slow to Shift at WOT
#2908157
04/08/21 08:06 PM
04/08/21 08:06 PM
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Joined: Feb 2009
Posts: 1,149 NW New Jersey
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OP
super stock
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super stock
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NW New Jersey
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Getting ready for fun at the Local Drag Strip and I have a concern. Last time I had the car out, and many times before that, I would bang my B&M shifter from 1rst 2nd, then 2nd to third and there was always a slight 1/2 - 1 second second delay before going into the next gear. The trans doesn't slip and the shifts are strong and positive. I have my shift light set for 6000 RPMs but by the time the trans goes into the next gear, the RPM is about 6100. Linkage appears to be set up correctly. The trans was rebuilt about 10 years ago with a cheetah reverse manual vale body and aside from the late shifts, there are no other trans issues. Any ideas?
1970 Superbird 440 Six BBL, 4-Speed, Dana, FJ5 1969 Daytona Charger 440 4-Speed, Dana, EV2 1971 340 Challenger Conv. Flemington Speedway Pace Car, FC7 1970 340 Six Pack Callenger T/A 4-speed T8 Tan 1971 340 Challenger RT Formal Roof, EV2 w/ V2 Stripe & Orange Houndstooth 1969 Talladega Torino, 428CJ 1969 Gurney Special Cyclone Spoiler II, 351 Cleveland
"Id rather have a bottle in front of me than a frontal lobotomy" Ben Franklin 1755
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Re: 727 Trans Slow to Shift at WOT
[Re: dvw]
#2908225
04/08/21 11:13 PM
04/08/21 11:13 PM
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Joined: Feb 2009
Posts: 1,149 NW New Jersey
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You have to set the shift light early. If its a stock valve body casting the amount of RPM gain increases as the car gets quicker. The feed to the front servo has a long path. You'll notice the 2/3 will have less RPM gain. To shift at 6900 my 1/2 is set at 6300. The 2/3 is set at 6450. This is in a 9.1X ET car. Doug So Doug, this is typical then? I have a good set of pills so I can adjust as needed.
1970 Superbird 440 Six BBL, 4-Speed, Dana, FJ5 1969 Daytona Charger 440 4-Speed, Dana, EV2 1971 340 Challenger Conv. Flemington Speedway Pace Car, FC7 1970 340 Six Pack Callenger T/A 4-speed T8 Tan 1971 340 Challenger RT Formal Roof, EV2 w/ V2 Stripe & Orange Houndstooth 1969 Talladega Torino, 428CJ 1969 Gurney Special Cyclone Spoiler II, 351 Cleveland
"Id rather have a bottle in front of me than a frontal lobotomy" Ben Franklin 1755
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Re: 727 Trans Slow to Shift at WOT
[Re: RSI700VIPER]
#2908226
04/08/21 11:23 PM
04/08/21 11:23 PM
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Joined: Aug 2003
Posts: 43,182 Bend,OR USA
Cab_Burge
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I Win
Joined: Aug 2003
Posts: 43,182
Bend,OR USA
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Have you adjusted the front band lately? If not do that next and see if that helps the 2/3 shift The other thing to check is the shifter linkage adjustment, you should be able to put the shifter in 2nd gear and remove the shift rod retainer and push the rod end up out of the shift arm from the tranny and see no movement on the arm, if that is good check 3rd gear engagement next. If either one move adjust the linkage so it does not move at all when putting the shift rod end into the shift arm hole in all 3 gears, reverse and neutral I've had and race with many 727 T/A Cheetah reverse manual valve bodies in both the early cable shifters cars and the 1966 and later tranny, all of them shifted quickly clean when adjusted properly
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 727 Trans Slow to Shift at WOT
[Re: Cab_Burge]
#2908317
04/09/21 08:03 AM
04/09/21 08:03 AM
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Joined: Feb 2009
Posts: 1,149 NW New Jersey
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super stock
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NW New Jersey
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Have you adjusted the front band lately? If not do that next and see if that helps the 2/3 shift The other thing to check is the shifter linkage adjustment, you should be able to put the shifter in 2nd gear and remove the shift rod retainer and push the rod end up out of the shift arm from the tranny and see no movement on the arm, if that is good check 3rd gear engagement next. If either one move adjust the linkage so it does not move at all when putting the shift rod end into the shift arm hole in all 3 gears, reverse and neutral I've had and race with many 727 T/A Cheetah reverse manual valve bodies in both the early cable shifters cars and the 1966 and later tranny, all of them shifted quickly clean when adjusted properly Will do
1970 Superbird 440 Six BBL, 4-Speed, Dana, FJ5 1969 Daytona Charger 440 4-Speed, Dana, EV2 1971 340 Challenger Conv. Flemington Speedway Pace Car, FC7 1970 340 Six Pack Callenger T/A 4-speed T8 Tan 1971 340 Challenger RT Formal Roof, EV2 w/ V2 Stripe & Orange Houndstooth 1969 Talladega Torino, 428CJ 1969 Gurney Special Cyclone Spoiler II, 351 Cleveland
"Id rather have a bottle in front of me than a frontal lobotomy" Ben Franklin 1755
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Re: 727 Trans Slow to Shift at WOT
[Re: RSI700VIPER]
#2908506
04/09/21 07:54 PM
04/09/21 07:54 PM
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Joined: Mar 2006
Posts: 9,836 MI, usa
dvw
master
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master
Joined: Mar 2006
Posts: 9,836
MI, usa
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You have to set the shift light early. If its a stock valve body casting the amount of RPM gain increases as the car gets quicker. The feed to the front servo has a long path. You'll notice the 2/3 will have less RPM gain. To shift at 6900 my 1/2 is set at 6300. The 2/3 is set at 6450. This is in a 9.1X ET car. Doug So Doug, this is typical then? I have a good set of pills so I can adjust as needed. In my experience, yes Doug
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Re: 727 Trans Slow to Shift at WOT
[Re: RSI700VIPER]
#2908725
04/10/21 12:31 PM
04/10/21 12:31 PM
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Joined: Jan 2003
Posts: 25,802 Rio Linda, CA
John_Kunkel
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,802
Rio Linda, CA
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A 1/2 to 1 second delay and the engine only gains 100 rpm?
The INTERNET, the MISinformation superhighway
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Re: 727 Trans Slow to Shift at WOT
[Re: John_Kunkel]
#2908784
04/10/21 04:45 PM
04/10/21 04:45 PM
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Joined: Mar 2006
Posts: 9,836 MI, usa
dvw
master
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master
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Posts: 9,836
MI, usa
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I even had the 2nd gear servo passageways on the valve body made larger, (Turbo Action Chettah). The rpm spread is better now for sure. But it still takes a given amount of time to complete the shift. The quicker the car, the more rpm lag it will have. This is checked using a play back tach. Also why many cars will go quicker with an earlier 1/2 shift point, they're being over revved. Mine runs a red hard band, aluminum drum, lightened sun shell, 3.8 lever. Same band and drum for well over 500 passes. Both looked new at last inspection. Doug
Last edited by dvw; 04/10/21 04:50 PM.
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Re: 727 Trans Slow to Shift at WOT
[Re: John_Kunkel]
#2908859
04/10/21 10:15 PM
04/10/21 10:15 PM
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Joined: Feb 2009
Posts: 1,149 NW New Jersey
RSI700VIPER
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super stock
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super stock
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NW New Jersey
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A 1/2 to 1 second delay and the engine only gains 100 rpm? At 6500 RPMs at WOT under full load, yeah about 1/2 plus second to go from 6500 to 6600.
1970 Superbird 440 Six BBL, 4-Speed, Dana, FJ5 1969 Daytona Charger 440 4-Speed, Dana, EV2 1971 340 Challenger Conv. Flemington Speedway Pace Car, FC7 1970 340 Six Pack Callenger T/A 4-speed T8 Tan 1971 340 Challenger RT Formal Roof, EV2 w/ V2 Stripe & Orange Houndstooth 1969 Talladega Torino, 428CJ 1969 Gurney Special Cyclone Spoiler II, 351 Cleveland
"Id rather have a bottle in front of me than a frontal lobotomy" Ben Franklin 1755
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