727 issues

I've been working on my 72 dodge motorhome. It has the 413 and the 727. Trying get it back up and running. Rebuilt the carb, redid the brakes, changed the rear gear oil out. Went to move it and nothing. So I pulled the cooler line and it was pumping out a steady stream. So went to test line pressure and I'm getting nothing from it. I have to have it moved out by next Monday so this is not good. Looking for any ideas, hoping it's something I can fix without pulling the trans. Now this did work when I moved it about a year ago but had no brakes then. I checked the fluid level in neutral and it was just above add a pint to I added a touch. When I shift it it doesn't feel like it's engaging at all. Now when I had the driveshaft off the transmission output would spin, but when driveshaft connected won't spin at all .

Where are you taking a line pressure reading? If you have no line pressure and the dipstick is reading in between add and full, it sounds like the lugs are broken off the pump gear.

if the cooler lines have psi I would think the pump is pumping. I would wait for Kunkel to come to & chime in (he's the man) but for now I would pull the pan & at least take a peek at the VB linkage

I checked the two ports on the passenger side and couldn't get a reading out of either. I ran it in neutral for awhile first then shifted into drive to check the pressure like my manual said to. But it's weird to me that I'm getting fluid through the cooler line. But it never feels like the transmission engages, no matter what gear I put it in. But when I had the driveshaft off the transmission output shaft would spin. I guess it could be really weak pump pressure and works when there's no load on it?

The center port between the two servos is line pressure. If the pump lugs have broken, there may still be enough drag to pump oil out the cooler lines but not enough to operate any clutches. With no load on the output it is not uncommon for the shaft to turn. You could try dropping the pan and checking the pressure regulator in the valve body but I think it's going to have to come out.

Oh OK

How do I check the pressure regulator?

It's tough to check the pressure regulator in the vehicle but if it is stuck, you may be able to see it if it is stuck open. The attached picture shows where the regulator is located in the valve body. There are two springs captured by the sheet metal retainer. The smaller spring and valve is your converter valve while the larger spring and valve is the regulator. Look at the regulator valve and see how far it is sticking out. you should see virtually all of the spring and a 1/2 inch or so of the valve protruding from the body.

Ideally one would drop the valve body out and split it to check but I wouldn't recommend that unless you are familiar with transmission repair.

Thanks I'll take a look, I've rebuilt a couple c4s but never a 727. Don't claim to be an expert but I get by just fine usually, I got an automotive technology degree while I was in college to break up the boring business classes.

That's my thinking too.

Is it common for the pump lugs to shear in a non hi performance situation? Not questioning the diagnosis, just curious guys.

I've only seen a couple cases where pump lugs were sheared off and they were both in race cars with high pressure manual valve bodies but I would guess it can occur with stock setups as well. The pressure in reverse in a Torqueflite is in the range of 250PSI and higher so that puts a strain on the lugs as much as a HP valve body.

I've seen 904's sheer the lugs in a non race application , but not a 727 , not that it couldn't happen.

Did you check the fluid level ? Try reverse ?

Yeah I checked fluid levels, it was fine. Tried reverse, drive, and got nothing. I checked the line pressure spring and it was fine. I'm going toss on a new filter toss in some type f and see if anything happens. If not who's the shop to send it to to be built right?

Checking the levels doesn't work to good when it's got the wrong dipstick. I was looking down at my catch pan and it dawned on me that there was only 1 or 2 max qts in the pan. Don't know why I didn't think that the dipstick might be wrong since the engines dipstick is a Ford trans one ( I hate people that do that crap)

Good catch. Top it up and it will probably be fine.