vso737
Well-Known Member
Well, still fighting this 1977 Chrysler A727 TCI Streetfighter auto/manual transmission. It worked great until I had T/C issues. First one sprung a leak at the weld. The second one had internal problems which caused trans fluid to burp out of the vent hole on cold starts- too much fluid drain back.
After installing the third 2400 stall 'break away' torque converter, the burping issue was resolved. I also replaced the pump with a rebuilt pump.
The current issue I have is LOW line pressure. D= 45 psi; 2nd= 45 psi; and 1st= 37 psi.
Best thing I did is to install studs for the pan. I have removed this VB probably ten times......
The other thing is putting a TEMPERATURE gauge (off of the rear servo port) and a PRESSURE GAUGE off of the line pressure port.
I have a B&M Quicksilver floor shifter with a Lockar TV cable set up.
I replaced the rear servo with a steel upgrade and cranked the valve pressure spring adjustment to 1" (it calls for 1 1/8" for competition), still LOW line pressure. The car slips real bad taking off from a stop. Once it gets going it shifts and down shifts fine.
Replaced the worn pressure valve with a "Sonnax LUBED pressure regulator valve. TCI techs tell me they NEVER heard of it and SONNAX claims the valve should work fine.
So, I purchased a used STOCK 1978 non-lockup valve body via Ebay. The VB looks much better than I expected and the vendor told me it came off a working truck.
I was elated to see that now I get 60 PSI in all three forward gears ( recommendation is 50-60 PSI)
The ONLY problem now, with the proper line pressure, the car will NOT move forward. It works great in reverse. I had to pump/play with the gas pedal quite a bit to drive it in the garage. I suspect an incorrect throttle pressure adjustment at the valve body.
I did NOT mess with the valve body pressure adjustments. The line pressure is set at the stock 1 5/16" and the throttle pressure appeared have a larger gap than the 1/8".
Which brings me to my next topic. The adjustment of the throttle valve at the VB. My "ATSG" manual instruction is to use a special tool, C-3763. I purchased the darn thing and it is NOT cheap. The TCI instructions and YOUTUBE videos I have seen use a 1/8" drill to gap the measurement. The ONLY two transmission shops that I find to be semi-trustworthy, both told me they NEVER use any tool. They did not tell me how they do the measurement/adjustment either.
Today I sent the VB that came with the transmission back to the builder to be tested. Can NOT wait to see why it would not put out the required line pressure.
In the meantime, I have the choice of dropping the pan AGAIN and adjusting the throttle pressure with my EXPENSIVE tool............OR, just wait for the original repaired valve body.
I want the automatic/manual function so I think I'll just wait.
I know NOTHING about transmissions but I'm getting to learn the A727 pretty good and it seems to be a transmission that I would NOT mind rebuilding. I think it is doable.........
I will be making a slide show from pictures of my work. I will post it when it is done for those who care to view it.
Had to replace my RR with my 1930 Model A Sport Coupe in the upcoming Solvang "wheels and windmills" car show on the 25th of this month. One of my FAVORITE shows.
LG,
Mike
After installing the third 2400 stall 'break away' torque converter, the burping issue was resolved. I also replaced the pump with a rebuilt pump.
The current issue I have is LOW line pressure. D= 45 psi; 2nd= 45 psi; and 1st= 37 psi.
Best thing I did is to install studs for the pan. I have removed this VB probably ten times......
The other thing is putting a TEMPERATURE gauge (off of the rear servo port) and a PRESSURE GAUGE off of the line pressure port.
I have a B&M Quicksilver floor shifter with a Lockar TV cable set up.
I replaced the rear servo with a steel upgrade and cranked the valve pressure spring adjustment to 1" (it calls for 1 1/8" for competition), still LOW line pressure. The car slips real bad taking off from a stop. Once it gets going it shifts and down shifts fine.
Replaced the worn pressure valve with a "Sonnax LUBED pressure regulator valve. TCI techs tell me they NEVER heard of it and SONNAX claims the valve should work fine.
So, I purchased a used STOCK 1978 non-lockup valve body via Ebay. The VB looks much better than I expected and the vendor told me it came off a working truck.
I was elated to see that now I get 60 PSI in all three forward gears ( recommendation is 50-60 PSI)
The ONLY problem now, with the proper line pressure, the car will NOT move forward. It works great in reverse. I had to pump/play with the gas pedal quite a bit to drive it in the garage. I suspect an incorrect throttle pressure adjustment at the valve body.
I did NOT mess with the valve body pressure adjustments. The line pressure is set at the stock 1 5/16" and the throttle pressure appeared have a larger gap than the 1/8".
Which brings me to my next topic. The adjustment of the throttle valve at the VB. My "ATSG" manual instruction is to use a special tool, C-3763. I purchased the darn thing and it is NOT cheap. The TCI instructions and YOUTUBE videos I have seen use a 1/8" drill to gap the measurement. The ONLY two transmission shops that I find to be semi-trustworthy, both told me they NEVER use any tool. They did not tell me how they do the measurement/adjustment either.
Today I sent the VB that came with the transmission back to the builder to be tested. Can NOT wait to see why it would not put out the required line pressure.
In the meantime, I have the choice of dropping the pan AGAIN and adjusting the throttle pressure with my EXPENSIVE tool............OR, just wait for the original repaired valve body.
I want the automatic/manual function so I think I'll just wait.
I know NOTHING about transmissions but I'm getting to learn the A727 pretty good and it seems to be a transmission that I would NOT mind rebuilding. I think it is doable.........
I will be making a slide show from pictures of my work. I will post it when it is done for those who care to view it.
Had to replace my RR with my 1930 Model A Sport Coupe in the upcoming Solvang "wheels and windmills" car show on the 25th of this month. One of my FAVORITE shows.
LG,
Mike