I have just put a 4l60e transmission in my 69 chevelle and when i went to drive it for the first time it will not go anywhere when i put it in reverse. it will bark the tires for about 6 inches when i bring the rpm's up to about 1500 but then suddnely stops as if it where in park, but it will move forwards in drive with no issues. i am sure that the shift seletor is in reverse and is not in between gears. does anyone have any suggestions about what might be causing these problems. i am completely lost and any suggestions are appreciated.

 

hmmm somtimes the 4l60's take a dump by the reverse gear that is welded to the outside of the sunshell break. the welds break causing the loss of reverse. ive seen this in a number of 4l60's. good luck with it man