1979 Dodge B300 5.9L V8 360 2bbl, A727 trans.

Ok so this is a fresh rebuild of a stock 727.
I have less then 10 miles on it and it's slipping in Drive 1st and slipping in Second 1st. Reverse and manual 1st are fine.
I checked the fluid warm at idle in neutral and it was about 1/8th above the low mark. I filled it a little and the level came up to a hair above the full mark. I tested it and everything was the same except manual first now had a thud into place when accelerating but that only happened a couple times. I readjusted the fluid level to a little above half way between marks and now the thud in manual first is gone but Drive and 2nd are still slipping.

I've ordered some line pressure testing equipment and it'll be here in a few days so I'll be able to perform some tests then...

What could this be?

Forgot to mention there are no leaks and that it was working perfectly at first.

Kickdown linkage present and properly adjusted?

What do you mean by drive is slipping? Do you mean both 2nd and 3rd gear slip during the shift? Or constantly? Both have different components applied to apply either gear.
Doug

Yes, that's what the last thread I opened was about...

It has no problem with the actual shift...
Once I shift into Drive first(D) it feels like the clutch is taking a little while to grip and once it gets going it grabs and accelerates fine. The same in Second first(2) but not as bad.
Reverse(R) is fine and Manual First(1) is fine.

So the problem happens at initial acceleration in Drive 1st and Second 1st but will grab and hold once it gets moving...

I’m pretty sure your problem is with the overrunning clutch. Putting it in “low first” applies the rear band, which does the job of the overrunning clutch, that’s why “low first” works when normal “drive first” does not. In third gear, the front and rear clutches are engaged, and the overrunning clutch is not needed. In reverse, the rear band is also applied, which explains why reverse still functions. Unfortunately the transmission would have to be completely disassembled to repair that.

That's what this chart is showing me...

I wasn't aware my transmission had an overrunning clutch! I rebuilt it and never once heard or read anything about an overrunning clutch. That's literally the only part of my tranny I didn't mess with when I rebuilt it!
Update: I was refering to the output shaft support that I didnt mess with... I didnt realize the sprag and overrunning clutch were the same thing. I took the rollers and springs out and cleaned them, I inspected everything and the rollers and springs looked new! There was a little wear in a couple of spots from the roller bearings but I smoothed that out... I also oiled it before assembly...
How though?! It was working perfectly when I installed it!

I'd like to do a pressure test to rule out any other possibilities before I pull it.
Could a damaged servo seal cause the same problem? Will a pressure test pinpoint the problem???

Maybe a rubber mallet could help knock something back into place or unstick something?

The 2nd gear and D positions both rely on the low roller clutch to hold the rear drum in 1st gear. If the roller clutch doesn't hold, 1st will slip. Unless you select manual low which engages the low/reverse band. But in my experience if the the roller clutch is intermittent it will shudder pretty good. They have to be pretty beat up to function intermittently. Did you check the rear drum for to see if the roller clutch was functioning during assembly? I suppose you could have installed the rollers and springs reversed.
Doug

Yes I checked by spinning the output shaft and it worked, it's also not intermittent... I'm not driving it around, I assume it can cause some serious damage if I drive it like that?

If I had put the rollers and spring backwards wouldn't it have been slipping from the begining? I drove it a few miles after install and it was working perfectly! The rollers and springs looked new and like I said before, the cam had a little wear in a few spots but I smoothed it out...

I actually do recall spinning the hub at some point to make sure it was working correctly but I guess it's possible I made a mistake if that's the only thing it could be???

I took my time on this and highly doubt I made a mistake but anything's possible...

If I have to take it apart again I actually don't mind doing it, I really enjoyed building it the first time but I have so many projects Id rather save the time and I'm hoping it's something I only have to take the pan off for!

So far all signs point to the sprag!

Ok since it's looking like a sprag on the surface I'll assume that's what it is and assume I'll be rebuilding it again...

So with the tranny disassemble are there any upgrades I should get?

I was thinking of getting a 16 roller sprag since it's only about $50 more than a refurbished stock sprag. Worth it or no??


Update:
Well??? Anyone???

Ok so tranny's out and disassembled!

Here's what I found...

The sprag is fine and not the culprit.

I found a snap ring laying in the extension housing.
It seams as though I may not have installed the medium snap ring that holds the governor body valve in place all the way and it popped off after a few miles...
That's why it was working perfect after install and started slipping later!
I'm so glad I don't have to buy a new sprag! I am so broke right now...

That will do it, like I said, it wasn't starting out in 1st gear unless you manually put it there.

Im not sure I understand. So when I shifted into Drive what gear was it going into?
So the governor regulates the pressure but from there I don't really understand where it goes and what other component it engages...

Is this normal wear??? I saw metal dust in the fluid, not a lot but enough to notice and it seams to have come from the converter hub but the bushing in the oil pump looks fine.
I still haven't inspected the pump gear so not sure if any metal came from there but I can definitely feel the wear on the converter hub with my finger and you can see in the picture a bit of light coming through between the hub and ruler.

Is it possible that if the TC pilot diameter is worn down a little it could throw the balance off enough to wear the TC hub like this?
If this isn't normal, and based off the metal dust in the oil I'll assume it's not what could be the problem?

Line pressure enters the governor and the governor converts it to governor pressure which acts on the shift valves to control the shifts. With that snap ring not seated, the line pressure passes right through the governor and engages third gear as soon as the shifter is placed in D. Placing the shifter in 1 overrides the governor.

I think the straight edge you're using to check the hub flatness isn't very straight.

That makes sense. Thanks!

As for the straight edge... I found something else... It's about the same.

Those pump bushings are pretty hard and will wear the hub. That is why many aftermarket converter companies recommend using a babbit bushing.

I remember reading something about that when I rebuilt it. The rebuild kit I bought came with some different colored bushings and I don't know what the difference is.
Take a look at the top picture... The bushing in the housing is the type a shop installed and the one on the left is the type that came with the kit I ordered. It's from Alto.
I'm still not sure what the difference of those two are and I'm currently getting ready to swap them out.

The bushing in question came with the new pump I ordered so I'm not sure what type but here's a picture of it...

If someone can take a look and offer their opinion on the condition of the inside of the TC hub and the corresponding surface of the reaction shaft I'll be greatful!
I noticed some very dark streaks around the base of the reaction shaft. I also noticed those two surfaces are very coarse...

You have the dimpled bronze bushing; the dimples retain fluid and are thought to be better but the dimples reduce the load bearing surface. Six of one, half dozen of the other. The original bronze bushing without dimples has been in service for many years with only scattered wear problems often caused by other issues.

The babbit bushing is softer and may be easier on the hub but will wear quicker; again a compromise.