rebuilt 4l60e dragging in reverse
07-05-2014, 03:06 PM
#1
rebuilt 4l60e dragging in reverse appreciate any help! i just rebuilt my 4l60e and installed it in my 72 nova. I have it on jacstands and can free spin the tires forward but cannot turn the tires backwards in neutral or reverse. if i run the car and put it in reverse it acts like the brakes are applied. Any ideas what could be my problem? thanks chris.
Last edited by novaskilling; 07-05-2014 at 03:23 PM.
07-05-2014, 08:55 PM
#2
Moderator
Your band might be too tight or its anchor pins not fully engaged.
Try checking the end play of the servo. Even with a tight fit in the tunnel, you can do this by pressing with a crow bar on the cover and measuring/estimating how much it moves in.
The proper end play is between .060 and .120 - i.e. 1/16" to 1/8".
If it seems less than 1/16" you might try removing just the cover and checking if this frees reverse.
I think a lot of people install the pump before the valve body and/or servo. I prefer to install the band, then valve body, then servo, before the pump. This lets me view/measure the servo end play, and by turning the output shaft, verify it is not too tight.
BTW - When you spin the rear tires forward, the low/reverse clutch freewheels and the front planet basically freewheels too, making it relatively easy to turn the output shaft in the forward direction. However, when you turn the output shaft (or rear wheels) backwards, the entire sun shell and reverse drum turn with a fair amount of resistance. In a properly working trans, it is about 3 times harder to turn the output shaft backwards than forwards. Hopefully this explains why I think your band is too tight.
Try checking the end play of the servo. Even with a tight fit in the tunnel, you can do this by pressing with a crow bar on the cover and measuring/estimating how much it moves in.
The proper end play is between .060 and .120 - i.e. 1/16" to 1/8".
If it seems less than 1/16" you might try removing just the cover and checking if this frees reverse.
I think a lot of people install the pump before the valve body and/or servo. I prefer to install the band, then valve body, then servo, before the pump. This lets me view/measure the servo end play, and by turning the output shaft, verify it is not too tight.
BTW - When you spin the rear tires forward, the low/reverse clutch freewheels and the front planet basically freewheels too, making it relatively easy to turn the output shaft in the forward direction. However, when you turn the output shaft (or rear wheels) backwards, the entire sun shell and reverse drum turn with a fair amount of resistance. In a properly working trans, it is about 3 times harder to turn the output shaft backwards than forwards. Hopefully this explains why I think your band is too tight.
07-05-2014, 09:08 PM
#4
Thanks for the great suggestions! Ill try that tomorrow and see if this cures my issue. I haven't drove the car other than on and off the trailer, so I can't tell you if it goes through all the gears. Hope it's just the band is to tight. Thanks again really appreciate it!
07-07-2014, 03:42 PM
#7
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adapt a case makes a nice piece to eliminate the anti clunk spring it comes with a new center support that it drilled and tapped and has a plate that bolts to it and uses the rest of the lugs in the case I use it a lot in my rebuilds it was designed as a case saver but works really well in performance apps
http://adapt-a-case.com/a74761dac.html
http://adapt-a-case.com/a74761dac.html
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07-07-2014, 10:25 PM
#8
Moderator
Bummer that you had to disassemble it again.
You might want to consider why the anti-clunk spring got loose; if there is case wear in the area you might want to consider Predator's suggestion to use a case saver.
You might want to consider why the anti-clunk spring got loose; if there is case wear in the area you might want to consider Predator's suggestion to use a case saver.