Dirty rotten stinking piece of C4 garbage!!!!!

bobbywalter said:

never noticed this thread. i will have to get to my note book. i have cracked a few cases with horror show results with these. they rock for 2wd drag racing though.


all the thrust goes to the rear...the selective kits and roller kits are worth the effort. maybe your housing is worn ...assuming your reusing the oem cage and thrust? stack up correct? springs right direction?

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The tail housing can't be the issue since the output shaft is locked up right now and the tail housing isn't installed yet. The problem seems to be at the rear of the main case, with the bushing between the one way clutch and the fluid distributor. The case didn't seem worn and the bushings were all replaced, but the internals are otherwise stock.

Stack up is correct according to the book I have, and as far as I can remember I never actually took the one-way apart. It was working, so I left it alone. The only thing I am not 100% sure of is that the high-reverse clutch is in the whole way. It looks like it can't go in any farther, but the fins on the shell don't sit the whole way into the slots on the drum below it which seems wrong.

i never mentioned tail or are you referring to the governor housing? the tail shaft on these bolts in from the back iirc...my memory isnt the best for this. but assume it turns fine with just the shaft and none of the inner shell ring stuff in place...i currently just got in ohio and on the way home in a bit...will look for my books when i get there to get up to task.

the inner one way race was never removed? the selective thrust is there and there is only one and it is the correct one? nothing got in there during the various assembly dissassembly?


when the trans is level does it free up a bit the whole way?

did you overdrive the case busing in? seems you would have noticed it polishing.


end play stack up is important, and you want it tight but your past tight.

the high reverse clutch...what was the pre measurement compared to spec? what is it now? are you using feelers? something is out of place if the pump is causing bind.

bobbywalter said:

i never mentioned tail or are you referring to the governor housing? the tail shaft on these bolts in from the back iirc...my memory isnt the best for this. but assume it turns fine with just the shaft and none of the inner shell ring stuff in place...i currently just got in ohio and on the way home in a bit...will look for my books when i get there to get up to task.

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Tail shaft has a weight or governor of some sort bolted near the rear. That drops into the dist block and keeps it from going to far forward. A snap ring in the rear shell keeps it from going backwards. I thought you were referring to the tail housing when you said "tail".

When the output shaft was initially installed this time it was stiff, but after being rocked back and forth a few times it turned fine, and continuted to turn OK until I put the pump in.

the inner one way race was never removed? the selective thrust is there and there is only one and it is the correct one? nothing got in there during the various assembly dissassembly?

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I don't remember ever removing the inner race of the one-way clutch. I know I had the whole thing out of the case, but I don't think I took it apart.

Selective thrust is there, I can easily turn the inner race one way, and not turn it the other way at all by hand. I don't think I got anything in it. I can't see anything in it.

when the trans is level does it free up a bit the whole way?

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No. The problem was actually discovered when we were installing the drive shaft and couldn't turn it to line up to the axle.

did you overdrive the case busing in? seems you would have noticed it
polishing.

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I actually managed to find the correct set of bushing drivers in the tool room when I did the bushings. They are all sitting flush, and aligned to their various lube passages.

end play stack up is important, and you want it tight but your past tight.

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Right, but the really weird part is the pump seems to fall right in, and go against the front of the case without any problems. I'm not going nuts or having to draw it in with the bolts. I don't remember if I said or not, but my pump bolts are only finger tight right now.

the high reverse clutch...what was the pre measurement compared to spec? what is it now? are you using feelers? something is out of place if the pump is causing bind.

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I have no idea. Initial disassembly and reassembly took place a few years ago, and I didn't measure anything this time because I was expecting to find that I'd torn a piston seal or something and that I wouldn't be replacing any parts that would change end play. I'll have to re-check end play, and probably try to assemble my last few pieces on the bench to see where they fit together outside the case.

I can't figure it out. I couldn't take an end play reading because my dial indicator is busted (yay), I'll have to see if I can find a friend with one I can borrow.

What I did do was compare my stack to the pictures in my book. It looks like my shell isn't going over the clutch packs as far as it is in the picture. So I cleaned the contact surfaces well, dabbed some vasoline on one side of each, and everything is bottoming out the way it should.

Ok, so I found some time to mess with this a little more today, still without a dial indicator.

This is what the front part of the stack looks like in every picture I can find.



This is what mine looks like.




So I took out all the clutches, from the packs and put it back together without the clutches, just to ensure there weren't any alignment issues. And then my stack looked like this:



So it seems to be a hard parts issue. But this problem cropped up without changing any hard parts.

piston / pressure plates in correct orientation?...right piston?


the long end of the sun gear correctly oriented?


every thrust washer accounted for and in correct position?


on edit...my notes only have clearances and custom valve body stuff because this is the second dumbest trans in the world and apparently cant be fawked up?


shows what i know! i am wrong again....

bobbywalter said:

piston / pressure plates in correct orientation?...right piston?

Click to expand...

The only thing that has changed from all this fitting and "working" (trans not locked up on full assembly) to now is that I took the high reverse clutch out, took it apart to inspect the piston seal, and reinstalled in right away. The next drum in that clutch pack bottoms out on a piece that doesn't get removed.

the long end of the sun gear correctly oriented?

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Sun gear in question is part of the notched lower shell. To install it upside down the whole drum has to be upside down. I might notice if I did that.

every thrust washer accounted for and in correct position?

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As far as I can tell. I ran across a few other reports of similar issues, even found one here, and every time it was the thrust washer behind the pump stator got out of place. It usually happened when someone tried to remove just the bell with the trans in the vehicle and the pump jumped too. My thrust washer is all but glued to the stator, and my issue seems to be lower in the trans.

on edit...my notes only have clearances and custom valve body stuff because this is the second dumbest trans in the world and apparently cant be fawked up?


shows what i know! i am wrong again....

Click to expand...

I can remove, strip, rebuild, reassemble, and reinstall a DPS6 without even paying attention and have it work as well as it ever will when I am done.

My ability to fawk up a traditional automatic transmission is nothing short of magical.

You are correct about this being the second dumbest transmission in the world. It has about 10 parts to it, and I can gut it and put it back together in less time than I can eat a sandwich. But for all of it's simplicity I really cannot for the life of me figure out what I am doing wrong, aside from maybe not engaging one friction disc in one of the clutches, but I think I have pretty well ruled that out. In addition to having the same problem with the frictions remove altogether every time I pull it back apart they are all lined up correctly, as if I had the inner drum in all of them.

i looked at the book and the sun i remember having an issue with....dont remember if it was a stack up like this or port passages for something..but i know it will fawk the stack like you picture....


custom pressure plates and selective snap ring are another source but this seems not applicable.










there should be a front and rear snap on the sun here....they orient a specific way....the wrong way stands off like it is pictured. i know you say you didnt touch it but its one thing i know that does this.

I'll try to check that sun gear today.

I flipped the sun gear over in the shell, it appears to be the same length on either side, and made no difference.

pic of it?

I didn't take a pic of the sun gear, I did notice while messing with it that the snap ring on one end sat slightly lower in the planet carrier than the other side did, but I had to clean up for a job coming next week, so the trans is "assembled" and sitting in the corner right now.

Here is where things get super weird though. I tried to put it together with the sun gear out, and it didn't help.






I have taken all the clutches out and stacked just the hard parts together, no change, I have taken the sun gear out so the shell sits right on the carrier, no change.

These parts are as far together as the go, but by comparing to every image I can find of the assembled internals of this trans this stack is nearly an 1/8th inch too tall.

The only thing I am aware of that can fix a C4 is in fact a pound of C4.... time for a C6?

BDAB said:

The only thing I am aware of that can fix a C4 is in fact a pound of C4.... time for a C6?

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C6 is for a big block.

I personally am thinking T5, but that opens up a whole new world of part I have to find.

I'm going to have my wife look at the stack, not because she is good at transmissions, but she is good with puzzles and such. I am convinced that this is one of two things at this point, either

A) Something so glaringly obvious that I can't see it because I can't conceive of having missed it

or

B) Some minute detail that a good transmission builder would catch quickly because of their experience, but I am just so frustrated that I keep missing it.

Looks like you're not splining the direct clutch to the forward clutch drum properly. When you push on the top of the that stack , does it feel springy?