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SAGA continues- TF A727 from hell

vso737

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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
 

dmartin

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Well Mike when I rebuilt my A727 I knew nothing about them but had a book on the A727 and a rebuild kid from TCI and it was easy to my first the only thing I did wrong was had the reverse band on to tight would not go in reverse now it works great
 

vso737

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Well Mike when I rebuilt my A727 I knew nothing about them but had a book on the A727 and a rebuild kid from TCI and it was easy to my first the only thing I did wrong was had the reverse band on to tight would not go in reverse now it works great

Is your A727 stock or did you make it a AUTO/MANUAL with the "TCI" kit. I guess one just changes the VB.
I still can't understand why I get LOW line pressure with the VB that came with the TCI Street fighter trans and I get perfect line pressure with the STOCK VB I put in the transmission. The car will not go forward with the STOCK VB which has perfect line pressure but reverse works great.
I sent the VB back to "TCI" for testing. Should know soon what the problem is.
I intend on reinstalling the "TCI" VB.
I don't mind taking a chance and rebuilding the entire transmission myself. I think it is doable..............
I have gotten real good on removing and reinstalling the VB and adjusting the front and rear bands..........................LOL

LG,
Mike
 

dmartin

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Mine is stock, have you checked the pump, you don’t have the lines crossed do you I mean I don’t know what it could be
 

vso737

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Mine is stock, have you checked the pump, you don’t have the lines crossed do you I mean I don’t know what it could be
CONFUSED with "crossed lines".
I installed a REBUILT PUMP and new THRUST BEARING. I have two REMOTE COOLERS in front of the radiator. Both connected in-line and the HOT outgoing line is suppose to go on the LOWER radiator connector. The TOP connector, COOLED fluid, returns to the transmission. I believe it would work either way but it is best for the fluid to TRAVEL UP the radiator. (the 'crook' that installed the trans of course had it backwards)
NOT a pump issue. My troubles started with when the T/C sprung a leak. I'm on the THIRD T/C and now those issues have been resolved. NO MORE burping fluid on a COLD start either.
MY current troubles are extreme SLIPPING from a dead start and NOT shifting properly..............So far, I know the VB is NOT putting out the proper line pressure.
LG,
Mike
 

vso737

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Is your A727 stock or did you make it a AUTO/MANUAL with the "TCI" kit. I guess one just changes the VB.
I still can't understand why I get LOW line pressure with the VB that came with the TCI Street fighter trans and I get perfect line pressure with the STOCK VB I put in the transmission. The car will not go forward with the STOCK VB which has perfect line pressure but reverse works great.
I sent the VB back to "TCI" for testing. Should know soon what the problem is.
I intend on reinstalling the "TCI" VB.
I don't mind taking a chance and rebuilding the entire transmission myself. I think it is doable..............
I have gotten real good on removing and reinstalling the VB and adjusting the front and rear bands..........................LOL

LG,
Mike
"Is your A727 stock or did you make it a AUTO/MANUAL with the "TCI" kit"

I purchased the "TCI" Street Fighter from SUMMIT RACING. All the 'bells and whistles' came with the transmission. I have "B&M" Quick Silver shifter with the Lockar cable.
I assume that replacing the VB in my tranny with the STOCK 1978 truck VB did NOT work is because the VB are NOT the same. I was going to replace the PRESSURE REGULATOR VALVE in my VB with the one from the 1978 truck. The one in the truck VB is LARGER than the one in my 1977 Chrysler VB.

LG,
Mike
 

dmartin

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I can’t remember but I ordered it from TCI not Summit
 

vso737

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Well, I just removed the VB for the 15th time......................NEXT time, the entire transmission is coming out. I'm letting it drain for a few days to remove as much of the synthetic fluid as possible. I suspect that a couple of quarts will most likely stay trapped in the T/C.

I'm going to reinstall the PRESSURE REGULATOR VALVE that came with the transmission. I currently have the "SONNAX" LUBE pressure regulator valve.
The line pressure reads 50 PSI (specs are 50-60) but once the fluid reaches normal temperature, the reading drops to 37 PSI.
This reading is with SYNTHETIC trans fluid. According to the "TCI" tech, the 727 uses CONVENTIONAL Dex/Merc trans. fluid.
If the pressure still drops, I suspect it is due to a worn VB. I'm NO expert, just a calculated guess..............

The trans. slips real bad taking off from a dead start. I also have quite bit of BLACK SLUDGE in the pan.............

I have a feeling that the next step will be a complete tear down.......................

LG,
Mike
 
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