charger 12 auto lacks power in reverse

[Jakeshorsetuff 36]

Hi everyone, I just rebuilt my 1968 sundstrand hydrogear because it had very little power going forward which after rebuilding it solved that problem. Now it has a very hard time backing up under stress such as backing out of a snow pile, back blading with a snow plow and, backing up a leaf pile with no stress it backs up fine. What I have checked so far is reverse check valve, reverse damping valve, and the fluid level. Before i rebuilt it had ATF dextron but now has ATF mercon v. Any help would be great. THANKS

[pfrederi 17,885]

#1 You should use Dex-Merc  the modern replacement for Dexron (no T) but I doubt that is your  reverse problem.  Does it creep in neutral?? have you done a neutral adjustment?

[Jakeshorsetuff 36]

It does not creep but I have never done a neutral adjustment.

[953 nut 55,809]

Were the Acceleration Valve Springs all in good condition? A bad spring can do that.

[Jakeshorsetuff 36]

 Yes, I replaced the Acceleration valve Springs during rebuilding because they were broken. Did not change anything.

[daveoman1966 3,762]

Do you have the NYLON CAM (5995) adjusted so that it makes FULL range UP / DOWN travel.  Play around with adjusting the CONCENTRIC (5996) to adjust this...MAYBE that will help.  There is a SH set screw to make the adjustment. 

    

[Jakeshorsetuff 36]

 Yes, I do have the nylon cam and the cam does not go down all the way on the reverse stroke so i am going to mess around with that today. I will keep you posted.

[Jakeshorsetuff 36]

Thanks everyone for your help, I had to adjust the cam so it would shift all the way into reverse. WORKS THE BEST IT HAS EVER WORKED.

[Sarge 3,463]

I can be tough to get those cams balanced, especially on the older hydrogear type Sundstrand. Another thing - it is common to see quite a lot of wear on the metal arm itself - I have had to weld up 2 of them and re-grind the profile to correct the wear. It makes a big difference in how far that cam plate travels and opens the direction valve - if it doesn't open all the way, you don't get full speed nor full power.

 

Sarge