727 reverse failing.

-
S

SuffolkPete

Member
Joined
Jun 30, 2020
Messages
6
Reaction score
0
Location
England
Hi out there.
I have a 1964 727 Torqueflite auto box which has just started to lose reverse gear (almost completely gone).It had being standing for many years. I have filled and drained it a couple of times before running under load. I'm just a regular guy so no heavy technical answers please. I have looked at other threads on this subject and have seen many different answers. None of them has mentioned something that I have noticed in my situation which is coupled with the reverse going. The oil level in the dip stick/filler tube is very high up inside. 3" above full mark. Way way higher than it should be. Could this be an indication as to whats going on. If I was to guess I'd say I have a blockage stopping the oil from recirculating back into the system therefore backing up. But it may well be something more onerous. Any help would be appreciated. Thanks.
 
A 300 psi pressure gauge, a length of hose with 1/8" npt ( not the parallel pipe thread you have there ) rated at the same and a good book or factory service manual can help pinpoint the problem. There are several pressure taps on the 727 case. I assume you're checking the level as it says on the dipstick - fully warmed up, idling in neutral, on level surface. You'll need a book for the pressure tests.

TF_8_Tech_Info__Pressure_Ports.jpg
 
rustycowll69 said:
how much fluid are you adding?
Click to expand...
I carefully filled to the line on the dipstick when engine was warmed up but not running. I now know it should have being running whist it was being checked/filled.But that's how it was done. As the engine WAS running I put it through the gears with the handbrake on at standstill.
I checked the level again today without starting the vehicle and it's still 3" above top filling mark.
 
SuffolkPete said:
I carefully filled to the line on the dipstick when engine was warmed up but not running. I now know it should have being running whist it was being checked/filled.But that's how it was done. As the engine WAS running I put it through the gears with the handbrake on at standstill.
I checked the level again today without starting the vehicle and it's still 3" above top filling mark.
Click to expand...
you didn’t answer my question. how many qts have you put in? And what are the circumstances?
 
rustycowll69 said:
you didn’t answer my question. how many qts have you put in? And what are the circumstances?
Click to expand...
Hi Rusty.
Got you. I'd say around 6.25 to 6.5 Qts.
I had taken the car out for a 15 mile trial run and all seemed well. It all went badly when I tried to turn the car round to get back in the garage the next day.
The forward gears work although I have a suspicion
that not 100%. Reverse is almost non existent as had to rev high to get it back into the garage. Hope that helps. P.
 
Last edited:
rustycowll69 said:
if you never drained the converter, that sounds reasonable. And you checked it fully warmed-up, idling in neutral, on level pavement?
Click to expand...
Checked it fully warmed up. On dead level workshop floor. But not running as mentioned earlier in tread. Which I now know is not what I should have done. :-( But filled with fluid as required in manual.
 
SuffolkPete said:
Checked it fully warmed up. On dead level workshop floor. But not running as mentioned earlier in tread. Which I now know is not what I should have done. :-( But filled with fluid as required in manual.
Click to expand...
does it move in forward gears, no delays? no hesitations, no jerking? If not, did you try adjusting the low/reverse band, when you had the pan off of it last?
 
SuffolkPete said:
Checked it fully warmed up. On dead level workshop floor. But not running as mentioned earlier in tread. Which I now know is not what I should have done. :-( But filled with fluid as required in manual.
Click to expand...
this is not a cable shift trans, right?
you did adjust the throttle pressure/kick down correctly, I hope?
 
rustycowll69 said:
does it move in forward gears, no delays? no hesitations, no jerking? If not, did you try adjusting the low/reverse band, when you had the pan off of it last?
Click to expand...
It moves forward. There HAS being a delay in engaging. No jerking though.
Didn't touch anything internally.
 
SuffolkPete said:
It is a cable shift. And marked the linkage on disassembly. And thought I had replaced accordingly.
Click to expand...
don't have much experience with cable shift. I've heard they can be tricky to adjust properly
For KD, when you have full throttle at carb, you should have full throw on the KD lever. Chk that. If not done properly, the trans will not build appropriate pressure with respect to engine power developed, when applying clutches, therefore clutches can slip and fry in short order.
 
Somebody probably put the newer filter in it. That blocks the rear pump pickup. You have to cut the gauze for the rear hole. And the rule if; is you don't know that your trans is to the full mark; shut it off. I've seen one quart low burn up a trans just idling. Never warm up your trans before getting it to the full mark. Two quarts low will definitely burn it up doing that. Check forward movement for low one engine braking; if you have that, then the rear servo piston seal is okay. Check third gear; the third gear clutch pack affects reverse.
 
SuffolkPete said:
Hi out there.
I have a 1964 727 Torqueflite auto box which has just started to lose reverse gear (almost completely gone).It had being standing for many years. I have filled and drained it a couple of times before running under load. I'm just a regular guy so no heavy technical answers please. I have looked at other threads on this subject and have seen many different answers. None of them has mentioned something that I have noticed in my situation which is coupled with the reverse going. The oil level in the dip stick/filler tube is very high up inside. 3" above full mark. Way way higher than it should be. Could this be an indication as to whats going on. If I was to guess I'd say I have a blockage stopping the oil from recirculating back into the system therefore backing up. But it may well be something more onerous. Any help would be appreciated. Thanks.
Click to expand...
Hi bud. You definitely have to check the fluid when it's at least warm and on a level surface. If your park break doesn't work just block the wheels. If the fluid checks out ok then take the car for a drive. Does it shift to second and third? If it does then slow down to about 10 miles per hour and manually downshift to first gear, you should feel the engine slow the car with a jerk like you hit the breaks. So if you have good up shifts, nice and crisp then your forward and third clutch and your second gear band are probably good. If you don't have engine breaking when you shift to first then you may have a cracked or burned low/reverse band or if your really blessed it could be a blown low reverse servo seal. I replaced quite a few of those in the 70's and 80's. Hope this helps sir.
 
You must log in or register to reply here.
-

Back
Top