TH400 not shifting - any tranny gurus?

[benjy]

I'm new to auto trannies, but slowly becoming more familiar. I need some help troubleshooting. Basically the trans isn't doing anything. When I shift through the gears it feels as if the motor isn't running.

I purchased a "rebuilt" TH400 from the guy rebuilding them on KSL. He has been pretty helpful along the way but is out of ideas. He installed a reverse manual valve body (part# TCI 221100).

What I have done:
- Properly filled TC and pan prior to installation
- Maintained fluid level as I started and ran it through the gears the first time
- Disconnected shift linkage and shifted manually through all gears
- Verified the transfer case is in gear
- Verified flexplate mated to motor, and torque converter to flexplate
- Removed the cooler lines to make sure the pump is working (and therefore TC properly engaged?)
- Removed pan and verified the shift linkage is connected with valve body

What I have not done:
- Swapped out the torque converter with a known good unit
- Put a pressure gauge on the trans to see if it's putting out the ~200psi(?) it needs
- Tried to roll the jeep to see if it acts like it's stuck in gear or neutral. I guess this would rule out the tcase in neutral theory, but... I'm confident the atlas is in gear and working.

Unknown factors:
- No governor tubes. As far as I understand, the RMVB eliminates the need for them? They should be plugged, I can't see any screws. Builder says they're not visible.
- No vacuum modulator. Again, eliminated by RMVB?

What would you do next? Any help appreciated

 

[benjy]

Quick video of disconnected cooler line after start up. Flows as good as I expected.

[video=youtube;OcfPemzcBTc]https://www.youtube.com/watch?v=OcfPemzcBTc&feature[/video]

 

[chadschoon]

Will it go into gear with some throttle? When mine had an issue it was because it wasn't building pressure (loosing it through a seal) but I could rev the motor enough for it to engage. As soon as I let off it would go back into neutral. Had to replace them with Teflon seals and it fixed the problem.

 

[benjy]

I've had it up to about 4k... what did it take for yours to engage?

Edit: Probably more like 2.5-3k, my tach isn't working and without an exhaust this is pretty loud.

 

[chadschoon]

Probably around 3k

 

[OutlawTJ]

A couple things to look at. remove valve body and make sure that metering plate gaskets are installed on the correct sides. If reversed it will not build pressure. Second would to pull pump and inspect sealing rings. Even though it may pump out the cooler lines doesn't mean its sealing in the drums. Its easy to cut a sealing ring when installing the pump

 

[Bart]

I can't view the video because it says its private, but when the pressure line on my Willys buggy blew before I had clamps on it, the pressure was incredible and blew all over the garage. So many things that may be wrong. Could be the torque converter, could be the manual valve body, could be the tranny.
Did you use an old TC?

 

[benjy]

A couple things to look at. remove valve body and make sure that metering plate gaskets are installed on the correct sides. If reversed it will not build pressure. Second would to pull pump and inspect sealing rings. Even though it may pump out the cooler lines doesn't mean its sealing in the drums. Its easy to cut a sealing ring when installing the pump

Since I have the pan off already I'll check the gaskets this evening.

I can't view the video because it says its private, but when the pressure line on my Willys buggy blew before I had clamps on it, the pressure was incredible and blew all over the garage. So many things that may be wrong. Could be the torque converter, could be the manual valve body, could be the tranny.
Did you use an old TC?

Interesting... I guess I need to get a pressure gauge on it. Torque Converter was supposedly new.

 

[cjncustoms]

If I were you I would take it right back to the Trans guy. Something's not right inside. Did you get the converter from him as well?

 

[Bart]

If the converter is new, I'd look at the manual valve body install first. It isn't building enough pressure from the sounds of it.

 

[Kiel]

Sounds like the valve body install went wrong. I did mine with that kit, and it was pretty easy. Maybe something with the check balls you have to place in the vb when you do the install?

 

[Shawn]

If I were you I would take it right back to the Trans guy. Something's not right inside. Did you get the converter from him as well?

X2 on that one. Don't touch it he may not warranty it.

 

[benjy]

Update! Life got crazy in the last 2 months, and I really need to get out in this thing to blow off some steam

I found a problem. According to the instructions, gaskets are supposed to be installed on either side of the separator plate. I only have one on the transmission side, not on the valve body side. Sounds like this could be my issue? I'll be calling TCI to get another gasket on Monday.

 

[Tacoma]

Could be, if it's not sealing right.

 

[cjncustoms]

Dude I can't believe you didn't take it right back to the tranny guy that built it! I hope this solves your problem though!

 

[neagtea]

Hope that fixes it,
Hopefully the builder followed the instructions some manufactures leave a sealing ring out and a o ring and install a plug here or there. Some th400 manuals run 2 balls and some change the size of the ball.
Let us know how it goes.

 

[benjy]

X2 on that one. Don't touch it he may not warranty it.

Dude I can't believe you didn't take it right back to the tranny guy that built it! I hope this solves your problem though!

Winners! It's going back up to the builder this weekend Anyone headed up to South Weber from Utah County any time soon?

I called TCI and he said the only way a missing gasket would cause this would be if there was serious warpage in the separator plate... some guys are even running without the gaskets. He seemed to think it was a stuck pressure regulator valve because it's getting good flow from the coolant line. So I put it back together today and hooked up a pressure gauge.

According to TCI, I should be seeing:

P- 180-200
R- 100-300
N- 180-200
1- 180-200
2- 180-200
3- 180-200

I'm seeing:

P- 70
R- 0
N- 25
1- 0
2- 0
3- 0

And a video showing the above. At least the 6.0 is running good

[video=youtube;k5DYyZFCyuM]https://www.youtube.com/watch?v=k5DYyZFCyuM[/video]

 

[cjncustoms]

Sucky deal Ben. Hopefully he gets it all fixed up for ya.

 

[benjy]

Since the last update, I ordered TCI gaskets. After I installed them it had forward motion but only over 3k rpm, and no reverse. Called builder, he was conveniently out of town for the next 2 months But, he did divulge that he installed a Coan valve body, not the TCI I asked for

I ordered the TCI 221100, installed it following instructions, and surprise! The thing is running, driving, and shifting like a champ. Time to see what this 6.0 is made of :greg:

 

[neagtea]

Congrats.