[Reneau1320]

Don't mean to be a pain in the ass, but this build is bringing it out.
Direct drum will not, under any circumstances, seat fully. When I place in the case, it feels like it engages the first set of frictions. But, the drum is impossible to rotate. I have pushed, pulled, shaken everything off the bench, and the drum will not seat, nor will it rotate.
I'm tempted to eat the cost of everything, buy the guy a rebuilt trans and let this thing sit in the corner for eternity

 

[Reneau1320]

Here's what I have done and what I found.
Removed the sprag, outer sprag race. Used the outer sprag race to align the frictions. Without the sprag, lowered the drum into the case. There is approximately .400 of shaft above the inner edge of the drum. The drum cannot go any further down. Can I assume that this the fully engaged position?

 

[57 Vette]

Here's what I have done and what I found.
Removed the sprag, outer sprag race. Used the outer sprag race to align the frictions. Without the sprag, lowered the drum into the case. There is approximately .400 of shaft above the inner edge of the drum. The drum cannot go any further down. Can I assume that this the fully engaged position?

 

[57 Vette]

I always leave the clutches out of the direct drum. It makes it a lot easier to grab inside the drum and turn at the same time to engage the clutches to seat the drum.
When the drum is all the way down the top of the center support splines is flush with the top of the drum.

 

[Hutch]

Air test int clutch while turning the drum. When it stops jumping at you, it's down.


Hutch

 

[Reneau1320]

I always leave the clutches out of the direct drum. It makes it a lot easier to grab inside the drum and turn at the same time to engage the clutches to seat the drum.
When the drum is all the way down the top of the center support splines is flush with the top of the drum.

I can see that. And, that's how I will continue. However, I cannot figure out why, when installed, I cannot turn the drum by hand. Should I be able to?

 

[Timbers68]

As others have said, leave the clutch/steels out of the drum (you can add them later) when you're trying to get it to spline into the intermediates. With the center support bolt installed you can apply 'hits' of air to the bolt while turning the direct drum and this should help it 'seat fully' where it needs to be.

I question why you can't turn the drum when loading into the case/Int clutches. Have you checked rear end play? With the drum out see if you can turn the output shaft. Then make sure you can turn the intermediate shaft (inside the case).

Also, make sure you use a rag on the direct drum when installing otherwise you may end up slicing your hand. I'll typically use a spare Int. sun gear shaft splined into the drum to help aid me load the drum. I assume you probably don't have a spare lying around.

 

[Reneau1320]

As others have said, leave the clutch/steels out of the drum (you can add them later) when you're trying to get it to spline into the intermediates. With the center support bolt installed you can apply 'hits' of air to the bolt while turning the direct drum and this should help it 'seat fully' where it needs to be.

I question why you can't turn the drum when loading into the case/Int clutches. Have you checked rear end play? With the drum out see if you can turn the output shaft. Then make sure you can turn the intermediate shaft (inside the case).

Also, make sure you use a rag on the direct drum when installing otherwise you may end up slicing your hand. I'll typically use a spare Int. sun gear shaft splined into the drum to help aid me load the drum. I assume you probably don't have a spare lying around.

Finally got the thing to seat. I did all the above, removed the clutches and steels, applied air to the center support, etc. You are correct, no spares laying around.
Without the direct drum, I can turn the output shaft and intermediate shaft fairly freely.. I have to use channel locks because I don't have enough grip in my hands. With the drum installed, I cannot turn the drum at all. It takes a good bit more effort to turn the out put shaft now.
The build continues today! Thanks everyone!

 

[Mudtoy]

Finally got the thing to seat. I did all the above, removed the clutches and steels, applied air to the center support, etc. You are correct, no spares laying around.
Without the direct drum, I can turn the output shaft and intermediate shaft fairly freely.. I have to use channel locks because I don't have enough grip in my hands. With the drum installed, I cannot turn the drum at all. It takes a good bit more effort to turn the out put shaft now.
The build continues today! Thanks everyone!

FWIW it sounds like there is something not assembled properly in the back half of that trans. You state that the direct drum will not turn at all, that is a red flag for me. Once the drum drops it generally spins nice.

 

[stuarta]

Should be able to turn the drum. Better take it apart and see what is wrong.

 

[Reneau1320]

FWIW it sounds like there is something not assembled properly in the back half of that trans. You state that the direct drum will not turn at all, that is a red flag for me. Once the drum drops it generally spins nice.

Yes, it is a red flag. I have assembled this trans step by step, according to the book, and up to this point, everything has went together nicely. I will be taking it back apart to find the issue

 

[Mudtoy]

Yes, it is a red flag. I have assembled this trans step by step, according to the book, and up to this point, everything has went together nicely. I will be taking it back apart to find the issue

There's a really good Sonnax article from 2015 regarding setting total end play on 400's, memorize it.

Good luck!

 

[Reneau1320]

There's a really good Sonnax article from 2015 regarding setting total end play on 400's, memorize it.

Good luck!

Excellent read, thank you

 

[Mudtoy]

Excellent read, thank you

There are a couple of sources for the shims and washers you need to properly set up front and rear end play. Sonnax and Coan come to mind.

 

[Reneau1320]

There are a couple of sources for the shims and washers you need to properly set up front and rear end play. Sonnax and Coan come to mind.

Rear end play is .008, front planet to rear planet is .012.
Attempting to install direct drum and it will not fully seat. Removed sealing rings and it still will not fully seat. Checked for burrs, nothing. Transmission shops are.not open till Monday so, until then......

 

[Timbers68]

Sometimes they'll just fight you. Few years ago I was fighting loading the direct drum in a 4L80e. Bugger just did not want to cooperate.

Start eliminating things.
Take out the Intermediate clutch pack. Install the direct drum make sure it seats all the way. Rotate it while it's in there. Make sure you don't hear any mtl. to mtl. rubbing sounds. If the direct drum doesn't turn stop here, something else is wrong.
With the direct drum on the bench fit each Intermediate friction onto the sprag race making sure there are no problems there.
If you soaked the intermediate clutches in oil try to make sure they aren't dripping with fluid. This will help in getting them lined up with the sprag race on the drum. Wipe down the steels with a paper towel (not a rag) for same reason.
Reinstall drum hopefully with success.

 

[cartruck]

Did you replace bushings on any of the planetary parts in this build? I looked back and see that without the drum installed (before you got that far) you stated you can turn the output shaft but it takes channel locks to not tear up your hand. If you are simply spinning the output shaft with no other holding/turning of anything else it should spin very freely...unless you have bushings that you replaced and are too tight which is a very common occurrence unless they have been honed to size after. Are you sure you didn't miss a bearing or thrust washer on the planetary stack and have 2 hard parts making contact? When all else fails you can put the planetary in a vice clamped at the tailshaft and stack the entire transmission on top, this way you can see what's hanging up, then stack the entire transmission in the case with no clutches so you can get a good feel for what's going on when turning. Oddly enough without clutches you can accomplish this very quickly.

 

[Mudtoy]

Sometimes they'll just fight you. Few years ago I was fighting loading the direct drum in a 4L80e. Bugger just did not want to cooperate.

Start eliminating things.
Take out the Intermediate clutch pack. Install the direct drum make sure it seats all the way. Rotate it while it's in there. Make sure you don't hear any mtl. to mtl. rubbing sounds. If the direct drum doesn't turn stop here, something else is wrong.
With the direct drum on the bench fit each Intermediate friction onto the sprag race making sure there are no problems there.
If you soaked the intermediate clutches in oil try to make sure they aren't dripping with fluid. This will help in getting them lined up with the sprag race on the drum. Wipe down the steels with a paper towel (not a rag) for same reason.
Reinstall drum hopefully with success.

This is good advice, systematically eliminate one thing at a time until the drum is just resting on the sun gear shaft splines. Then work up from there.

We still need to address the tight output shaft situation, see next post.

 

[Mudtoy]

Did you replace bushings on any of the planetary parts in this build? I looked back and see that without the drum installed (before you got that far) you stated you can turn the output shaft but it takes channel locks to not tear up your hand. If you are simply spinning the output shaft with no other holding/turning of anything else it should spin very freely...unless you have bushings that you replaced and are too tight which is a very common occurrence unless they have been honed to size after. Are you sure you didn't miss a bearing or thrust washer on the planetary stack and have 2 hard parts making contact? When all else fails you can put the planetary in a vice clamped at the tailshaft and stack the entire transmission on top, this way you can see what's hanging up, then stack the entire transmission in the case with no clutches so you can get a good feel for what's going on when turning. Oddly enough without clutches you can accomplish this very quickly.

Sun gear shaft bushing (the long one) can be tricky. I typically do the stack up mentioned above by sticking the tailshaft through a hole in the bench. More stable than a vise and not as scary for your toes or the splines.

Question for OP, you are assembling the entire rear stack (compound planetary) and then using a tool to hold the tip of the main shaft and drop the entire assembly into the case right?

Things can get weird when you try to drop it in piece by piece...

 

[Reneau1320]

Sun gear shaft bushing (the long one) can be tricky. I typically do the stack up mentioned above by sticking the tailshaft through a hole in the bench. More stable than a vise and not as scary for your toes or the splines.

Question for OP, you are assembling the entire rear stack (compound planetary) and then using a tool to hold the tip of the main shaft and drop the entire assembly into the case right?

Things can get weird when you try to drop it in piece by piece...

Okay, taking more of the great advise on here we, my neighbor and I have located the problem.
The intermediate shaft was not fully engaging the sun gear. This was due to the new bushings I installed. A few minutes with some ultra fine sandpaper and now everything is smooth!
And, yes, I do install one component at a time. Thank you all so very much!