Before I reinstall - is it possible to do a visual inspection of the tranny and identify condition ? It seemed fine the few times I drove it before resto started , just be nice to know all appears well .............
727 bench check ?
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omahamoparguy
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Not really but you could pull the pan. I think you can see the front band/drum. Air pressure check would tell you more. Do a search or look for a vid on youtube to do the check with air pressure.
DaveBonds
Garage Trash
If you go through a factory service manual, it gives you a diagram, showing which passages in the body of the transmission run hydraulic pressure to which components.
If you use an air nozzle with a tapered rubber end on it, you perform an air pressure check with an air compressor and it will actuate parts as you perform the test on each port. I do this to all of the Torqueflites that I go through, before assembling the valve body and the only gasket it requires replacing is the pan gasket, which should be done with a filter anyway, upon reinstallation after it's been used a bit.
It doesn't take much air pressure. Essentially, you are just using air pressure as a diagnostic to actuate parts and listen for leaking in the case, to check the clutch apply piston seals and correct operation of band apply servos.
Aside from that, if you wanted to pull the front case cover at the input shaft and replace that gasket, you can physically measure the amount of gap between the clutch and ring packs and the engage piston, with a feeler gauge, at the snap ring. If it's within tolerances, button it up. If it's loose, replace the clutches and steel rings. One thing that doesn't take much effort at all is to do band adjustments. Low reverse is done on the inside of the trans, from the pan side and can be done easily with the valve body out. I can't remember if you even need to remove the valve body, it's been a while. The kickdown is done on the driver's side from the outside. Adjustments are similar to carb idle mixture screws. hand tight (with a 1/4 drive ratchet, it's inch pounds on these, if you want the actual numbers they are available) and back off to specific number of turns, lock the jamb nut.
The air pressure test is a great way to check the basic functions of the trans. The factory service manuals tell you what pressure to run into the circuits, where they are and what expected results should look like and sound like. I've caught a few problems and corrected them by doing this and all it takes is removing the pan and valve body, which is a quick operation that can even be done under the car.
If you use an air nozzle with a tapered rubber end on it, you perform an air pressure check with an air compressor and it will actuate parts as you perform the test on each port. I do this to all of the Torqueflites that I go through, before assembling the valve body and the only gasket it requires replacing is the pan gasket, which should be done with a filter anyway, upon reinstallation after it's been used a bit.
It doesn't take much air pressure. Essentially, you are just using air pressure as a diagnostic to actuate parts and listen for leaking in the case, to check the clutch apply piston seals and correct operation of band apply servos.
Aside from that, if you wanted to pull the front case cover at the input shaft and replace that gasket, you can physically measure the amount of gap between the clutch and ring packs and the engage piston, with a feeler gauge, at the snap ring. If it's within tolerances, button it up. If it's loose, replace the clutches and steel rings. One thing that doesn't take much effort at all is to do band adjustments. Low reverse is done on the inside of the trans, from the pan side and can be done easily with the valve body out. I can't remember if you even need to remove the valve body, it's been a while. The kickdown is done on the driver's side from the outside. Adjustments are similar to carb idle mixture screws. hand tight (with a 1/4 drive ratchet, it's inch pounds on these, if you want the actual numbers they are available) and back off to specific number of turns, lock the jamb nut.
The air pressure test is a great way to check the basic functions of the trans. The factory service manuals tell you what pressure to run into the circuits, where they are and what expected results should look like and sound like. I've caught a few problems and corrected them by doing this and all it takes is removing the pan and valve body, which is a quick operation that can even be done under the car.
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