727 not shifting into gear

[Sjd556]

my 727 is shifting into reverse but not into 1,2 or 3rd gear. It rolls in neutral, won’t roll in park and shifts into reverse but can’t get any of the drive gears. I am running a burst quarter stick and thought maybe my adjustment was off, I took the cable off and checked the adjustment but it seemed fine.. I haven’t pulled the pan yet, so not sure on how the fluid looks, that’s the plan for tomorrow but it indicates on the dipstick in neutral that it’s at a good level when warm. The converter is a 2500 Hughes and it was all freshly built and the first time it was run. I’m open to ideas before I tear into this thing, although I’m guessing that’s the only way to know for sure...

 

[dvw]

Was this a sudden failure? The rear clutch is applied in all forward gears only. If there's junk in the plan, I'd look there.
Doug

 

[Sjd556]

Not sure, Trans was freshly built by a trans shop

 

[66Satellite47]

Yup, sure sounds like the rear clutch failed.

 

[oldbee]

1st time ran since rebuild? Maybe a seal rolled and pressure not getting to clutches? Trans shop close?

 

[Photon440]

But even if the sprag clutch failed, it should still go into first by manually selecting low gear. I had that problem.

 

[dvw]

But even if the sprag clutch failed, it should still go into first by manually selecting low gear. I had that problem.

This statement is correct. However not applicable to the failure here. I meant the rear clutch assy that is attached to the input shaft. Without it functioning there will be no forward gears.
Doug

 

[Sjd556]

1st time ran since rebuild? Maybe a seal rolled and pressure not getting to clutches? Trans shop close?

No trans shop is a few states away unfortunatly

 

[Sjd556]

Draining the pan right now, will let you know what I find

 

[Fran Blacker]

 

[Sjd556]

Well here’s what the pan had to show. Should I pull the trans? Is any metal in the pan acceptable?

 

[dvw]

If this is a new build it may not have damaged the clutch. It may just be a piston seal or sealing ring on the input shaft. As long as the pan is already off. Why not pull the valve body and air check the clutch? Only the 2 bolts on the linkage and 10 on the valve body. using a rubber tipped blow gun you should here a thud when air is applied. Compare it to the forward clutch.
Doug

 

[Sjd556]

Thank you, that will be my next step, in about 2 minutes

 

[Fran Blacker]

You may have turn driveshaft as you remove and install valvebody. I got out no problem had dvw why it wouldn't go in.

 

[Sjd556]

Got the valve body out, everything looks clean, don’t have access to air tonight so will have to bring my compressor home from Work tomorrow. The bands seemed really loose I could move them with ease with just my fingers is it possible they weren’t torque down and adjusted correctly? Or is this typical

 

[Sjd556]

Also I should mention that most of that stuff in the pan is actually rust in the pan, not grime. There was a small amount of metal film like substance at the bottom, however it was minimal

 

[Sjd556]

Few more pics since I don’t really know what I’m looking at

 

[dvw]

The bands aren't you issue. You should be able to pull the band levers away from the pistons 1/4"-5/16". The rear band is functioning or it wouldn't go into reverse. The front band is applied in 2nd gear only. Look at my diagram it shows both the rear clutch and front clutch apply holes. That's where you want to put the blow gun.
Doug

 

[66Satellite47]

There is almost always a little bit of fine metal dust in the pan. Piston lip seal failure in the rear clutch would produce the no forward gear result. Seems to me a low pressure condition would come on slowly with some "slipping" before the no forward condition. Air to the rear clutch apply hole will tell the tale as dvw said.

 

[Sjd556]

Thanks, will give it a shot one I get out of work