Yep that's what I've got. Just using the paper clip method to check codes. I have an ALDL cable from Red Devil River but haven't been able to get it to communicate with the pcm.

From everything I've read in the last 2 days it seems like it's the forward/input sprag that has failed. Not sure why it worked fine for a couple miles then failed.

It's listed as the common issue list for no movement in OD and D, but L1, L2, and R all still work.

 

So just dropped the pan in preparation to remove the whole transmission again. No metal at all, but I did confirm one of my other suspicions. . . The filter seal had come out of the pump despite the gasket sealer. . . I should have used epoxy I guess.

Seems like I shouldn't have had any movement at all, but I'm thinking the pan was holding the filter in enough, or I just had enough fluid that the pump was getting fluid. Since there was no noise when I lost 3/4, and no metal I'm going to try fixing the seal and see if there was just not enough pressure to engage the forward clutches.

I couldn't haven't installed the sprag wrong in the first place because everything worked correctly for a few miles.

Fingers crossed that it was just the filter falling out, and that low pressure didn't fry my new clutch packs.

 

Good luck that it is a quick fix.

 

Thanks . . .me too. Although trans internals are never really a quick fix. I did get everything torn back out yesterday except for the transmission itself. My attempt at fully seating the filter seal and trying again didn't yield any different results.

Planning to work more this afternoon to get it out again, then back inside of it to see what the issue is.

I ordered a new sprag, but didn't get any more clutches. Hopefully they will all still be ok. Worst case is I could put the old clutches back in, but obviously that's not the best idea.

 

You have the manual with the troubleshooting guide, do you?

 

I have the Blue ATSG manual, and the color eBook you shared with me. Between the manuals, and a few more hours of searching I'm 99% sure my Forward/Input Sprag has failed. . . .Of course one of the only hard parts I had out of the case but didn't inspect closely. Checked rotation, but didn't disassemble it.

Only other thing it could really be other than the sprag is a big leak in the forward piston apply circuit somewhere.

Figured with a rebuild 20k mi ago that I didn't need to worry about it. Strange that it would fail right after i put it back together. . .unless I caused a pressure leak.

Should know later on today. Got the trans back out Tuesday, but haven't opened it back up again yet, so going to work on that today.

 

Found my problem:



Sprag exploded. . .or rather disintegrated. Fortunately, it was all still contained inside the sprag assembly. Stopped on my way home earlier and picked up a new sprag element from a local trans parts store.

Checked the clutches again, Over run and forward frictions were still perfect. 3/4 pack was already a little discolored but otherwise looked fine. Also, noticed a little discoloration on the band already too. Since it all still looked pretty good I went ahead and put it all back together.

This time I bought some green Assembly Goo and coated everything much more liberally than I did with the Vaseline last time. . .Just in case that had something to do with the failure.

Most likely it was ready to give up before and I didn't notice since I didn't crack it open to inspect.

Just took a break but trans is together and ready to be reinstalled, again. Planning to spend all day tomorrow working so will hopefully have good new by the afternoon.

 

Just got it all back together and went for a test drive. 2nd time in and out was much faster, after refreshing my memory on the 1st attempt. . . Been 12+ years since I've R&R'd an auto.

I've fixed the sprag problem as I have forward movement in OD and D now. Doesn't seem to be really grabbing 4th now. . . Thinking the new band and drum have broke in enough now that I need to go back and add the Shim back to the servo.

1st time I put it back together it all seemed to tight so I left the shim out. I know I installed the 4th servo piston in the correct direction, so can't be that. Of course now it's nice and hot so going to have to wait a bit to pop the servo cover to add the shim and try again.

Other than that, unless I somehow didn't get a solenoid plugged in all the way not sure what it could be. Possible I used so much assembly lube it's not fully dissolved, but that seems unlikely.

 

Son of a biscuit. . . Tried topping off and a 2nd test drive. Realized I actually don't have 3rd or 4th. It starts out in 2nd and doesn't shift. I can get 1st in L1. .

Looks like somehow I managed to install the spag backwards?!? SMH. . .I checked it like 3 times after installing the new element. Guess I over thought it, as I had it installed one way. . thought I had it wrong, checked the book, which appeared to confirm this. . .so i switched it around.

Should have checked the ATSG manual as well, but the detailed color pictures of the Cliff McCormick book error_401 shared earlier have been more helpful overall.

I checked the sprag holding it horizontally, instead of vertically (how it sits installed) like how ATSG shows it. Pretty sure that along with my brain not working contributed. Had only slept like 2hrs the night before come to think of it. . .

So I guess the project is on hold again. . . Will have to pull it back out when I have time. One positive note is I'm getting much more efficient/faster at removal and re-installation again lol. . . this time I'm thinking I'll be able to do it about as quickly as I used to at the shop back in the day.

 

Uhh - still only thing left is - I wish you good luck and a lucky hand this time when putting it together.

Thumbs up!