Freshly Rebuilt TH400 issues.

[HotRodPC]

I agree with you and @crazy4offroad both. He's right, you will have to tear it back down and go through it again. But by all means, the damage is now done so if you can troubleshoot it and get it corrected before it's totally burnt up then try to do that, but I'll assure you, you don't have long. You probably don't even have 100 miles left, maybe less than 50.

 

[86Peter454]

No I never touched the paper gaskets. The article I followed didn't say to so I didn't. As a matter of fact no article I read about dual feeding or anything said anything about modifying the paper gaskets.

So it is possible this is causing my issue. What part of the gasket needs modified and is it just the valve body gasket or both the vb and case gasket?

as for if my plugs stayed plugged. id assume so. they where all done with set screws and used red loctite to keep them in place.

But yea I have maybe 5 miles on the truck if even that. So for sure gonna redo the cluches and flush everything out once I figure out what the issue is here.

 

[86Peter454]

okay so i got the valve body taken off and i cleaned the crap out of it.

i double checked the valve body gasket was the right one and that all the holes where sized correctly and all seem good on that front.

it was possible i had a valve in wrong on the valve body or that one of my valves was sticking.

got it put back together and took it for a test drive tonight. it seemed to do much better but not perfect.

so in first if i just take my foot off the gas the truck doesnt move like it does in reverse. i have to actually apply gas to get it to move not sure if that could just be converter soaking that up or if that means the trans is slipping.

so it doesnt feel like its slipping as bad now though possibly verry little slipage. it made the screaching sound one time in first but not like it did before in the videos and not when shifting to second from first.

i did try to get into it a bit to see if i could roast a tire and it didnt. i did not try to power brake it or anything to get it to. i feel like if it will roast a tire then the trans is not slipping but since it wont i guess it could still be slipping.

QUESTIONS
the the pressure is still pretty high like close to 200psi how do i lower this down to like 150?

anything else i should test to prove its in working order? im pulling it out tomorrow (saturday) afternoon to rebuild the clutches and stuff so if there is anything else i should test while its still in the truck please let me know so i can try it.

thanks for all the help guys im open to anything.

 

[86Peter454]

so ive got the trans out.

i got another rebuild kit with mostly just new clutchs steels and seals and stuff not a full kit.

so im working away finding that the clutches are all in really decent shape like not what looks like an excessive amount of wear.

i did the intermediates then the directs then i get to the forwards annnndddd i found the issue.

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hopefully you can tell the issue in these pics.

the forward drum was making contact with the direct drum. most of the damage was on the forward drum the direct barley had any wear on it.

the direct drum is out of a 4l80e but no one has mentioned this to be an issue when using a 4l80e drum.

this would explain the screeching sound and why the sound started to go away as it "self clearanced" and why first felt slippy as i assume it trying to turn the forward drum and direct drum at the same time probably was hard on it (actually now that i think of it does the forward and direct turn the same direction?) as far as i can tell my sprag is still good it only turns clockwise so i dont think it caused any damage there.

so i guess my question is now.

what sets the direct drum to forward clearance? i had a bushing between them but not sure if that matters. would not having the direct drum sitting all the way down in the intermediates cause this?

any help is much appreciated guys.

 

[86Peter454]

anyone got any ideas to make these not hit each other?

EDIT:

so i think i found the issues.

when i took the forward drum apart it was missing this bushing.

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its the one on the other side of this one.

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without the bushing the forward drum and the direct drum look like this.

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i cant fit any feeler gauge between them.

with the bushing they look like this.

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and that fits a .019 feeler gauge between it.

not sure if thats enough gap but its more than none lol. so i guess ill put it back together and see how it does with that.