Technical th 400 transmission wont go in gear

I hope I'm allowed to post about this trans its in my 49 Hudson. I bought the car less motor but was set up for a BBC. I dropped in a SBC after moving the mounts and finally fired it up over the weekend. The guy I bought it from said the trans was good but it did sit for years well its showing full on the dip stick put it in gear nothing happens the cars in the air and it doesn't move a tire at all in any gear. I did fire the motor up once before I built the exhause and forgot the trans lines were not hooked up and it puked up fluid from the lines only ran maybe 15 seconds I shut it off and looped a hose from one to the other to be able to start it without leaking everywhere. I filled up the torque converter before installing am I missing something? Is it possible I don't have the converter in right it runs and idles with no strange noises but doesn't even idle down like an automatic does when I drop it in gear like it has no pressure

 

simple stuff first:

you say that the dipstick reads full...is that while the motor is running?

did you bolt the flexplate to the torque convertor?

 

Did you have the Pan off ? You should have and changed / inspected the filter. The filter feeds off the bottom thru a tube to the top. I've seen broken tubes, short filters in deep pans And even no filters.

 

Checked both engine running and engine off warm and cold it doesn't move on the stick and yes the converter is bolted to the flex plate I haven't pulled the pan yet as it was raining and muddy outside today. How can I tell which I have deep pan or not so I know what filter to order? Also the shift linkage is hooked up and feels like its working correctly

 

You need to measure the depth of the pan. So far ive only seen 2 different depths But my Trans guy says there are 3 different ones from GM and then there's aftermarket too. The pan bottom actually holds the filter in place.

 

OK I'll have to take it all out and hopefully the parts store can match mine up. Really hoping for the best I really wanna be able to drive this car this season but my gut tells me the tranny is shot and a replacement or rebuild isn't in the cards right now.

 

Don't sing the blues yet. May not be too much to remedy. Can you remove the trans pan with it in the car? Do that and have a look inside, replace the filter, refill fluid...
Good luck!

 

Do you remember when you bolted the engine to the tranny when you were bolting the converter to the flex plate did you have some clearance between the flex plate and converter or was it tight and hard to get the bolts to line up.

 

Hi
I have had trannys just like what you have explained. Did you have the torque converter off the tranny ? If you did not align the driver tabs when putting the converter back on tranny,when you bolt the tranny to engine it will brake the oil pump. Take off a coolent line to see if it is pumping oil. All the trannys I bought over the years was junk and needed overhauled. Good luck on used trannys.

Toxic Waste

 

I think I may have shot my self in the foot when I stuck it together the motor was out of a stick car and it took forever to get the bushing out of the crankshaft and it was getting late I stuck it all together and thought it I had it all lined up right but thinking back I think I had a little trouble getting it all aligned maybe the converted didn't seat in the pump drive correctly.If it didn't what kind of damage can I expect pump? Converter? Both? Looks like I'll be pulling this thing by myself again Ill try the filter and fluid change first but I figure it do something if that's all it was

 

How much fluid did it spit from the open lines in those 15 seconds.
Should have been one hell of a mess if the pump is good.

 

Yea it pumped out a good amount

 

Does the shifter feel like it has detente,I have seen the valve body not hooked properly to the shifter.

 

This statement is of particular interest to me...lol. A big block chevrolet will generally bolt-in anywhere a small block will and vice-versa. Why did you have to move the mounts?

Automatic transmissions will sometimes do funny things if they've been left to sit for a very long time. The rubber parts can dry up and crack and not hold pressure...and rust can form in places that cause damage to the rubber parts the first time you try to activate it, etc.

 

Check and see if your local parts store has a tranny pressure gauge you can rent if so get a manual and check the pressures as the manual instruct.

 

I moved the engine forward about 1/2 to 3/4 inch because the driveshaft was all but bottomed out in the trans the way they had it set up. It feels like the shifter is working OK but I'll disconnect it and try that. Hopefully it doesn't rain today and I can let you guys know more

 

So I dropped the pan today the local advanced auto didn't have a trans filter/gasket big surprise but it'll be here tomorrow. Pan had some gunk in it but I've had worse in perfectly working 350 turbos. I checked the shift linkage wile the pan was off and it seems to be working correctly. Really hopeing the filter was just clogged but I'm pretty sure its either the pump or converter I have a line on a 4wd trans I can use for parts should the pump and converter swap over if it turns out mine is bad? How hard is it to change the pump out?

 

I would not even consider "just changing the front pump". If you're going to tear it down you might as well go through it. Would be a shame if you went to all that trouble only to put it back in and discover the same problem still. 400s are a breeze to overhaul. You really don't even need any special tools if you're crafty.

 

https://www.youtube.com/watch?v=ScwJLi1206E

Watch youtube it will help you understand how 400's are put together. There not that hard to rebuild. Just alot of time cleaning parts.

Toxic Waste

 

There is a place near here that says on there website they will sell a rebuilt one for $425 I think it was plus core charge with a one year warranty that doesn't sound to bad but not money I have to spend right now. Might be a cheaper route than trying to rebuild it myself although I'd like to learn I really want to go to a couple shows this year and I'd hate to speed 140+ on a rebuild kit and who knows how much on broken parts plus 30 or 40 on videos and or how to books to have a tranny that may work or may not work I did watch about 5 videos on you tube on how to take one apart/assemble and they don't seem to bad to work on just really was looking forward to being able to drive this thing for the first time. I think I'm going to see what happens with the new filter/fluid if that don't work I'm going to try the other converter/pump if that works I'll drive it this summer and try to rebuild myself this winter if it don't I'm gonna pony up the cash for the rebuilt one

 

$425 isn't that bad for a done-over TH400 and you'll only be spending your money once.. and getting a warranty to boot. The only thing I've come across in a TH400 was cracks in the case, a couple of times I had to round up another core for them.

Another option is a later model 700R4 that will come with OD and they're plentiful in the 'yards.

Bob

 

You removed the filter, but did you remove the tube that supports it?
There is an o-ring on the tube that will split and cause the pump to suck air.
What kind of "junk" was in the pan?
Was there a mark on the pan where the filter was resting?
I had one where they put the wrong length tube (short) in and it was sucking air.

 

Just the real fine stuff on the bottom of the pan mostly on the magnet in the pan my past 350 turbos were way way worse and still worked fine. I pulled the filter I left the tube in there but I pulled the o ring off the filter where the tube slides in and it looks fine it doesn't look like the filter was touching the bottom it had one support bolt holding it up. Also a spacer about 3/4 inch long fell out after I dropped the filter I'm assuming this goes above the filter on the mounting bolt? Kinda a tight squeeze under my car

 

Got the new filter and fluid in and it turned the wheel just barely then stopped so I let it idle a wile ran it through the gears and if I shut it off and restarted it it would turn the wheel about ten turns then stop. so I let it idle a bit more and its still not doing anything but it will start to kind of chatter then kind of get a little louder then quiet down and chatter again. Is it possible I have this all bolted together but don't have the torque converter seated into the pump. It all looks normal and at idle its quiet for a wile then after about ten mins it starts to chatter

 

What does the tranny fluid level do say when you let it set does it go up and then when you start it does it go down to the full level?

 

I accidentally overfilled it so its hard to tell how much the fluid level changes but don't look like much. What would I look for in the pump and of converter to tell if they are broken? I'm going to try to pull it out tomorrow I crawled under it with it running and the converter and flex plate look like they are spinning true no wobbles or anything. I also took off the linkage and shifted it by hand to rule that out as well

 

Well if you remember the converter tight against the flex plate when you put it in then you need to remove the tranny pull the converter take a light and shine it downe through the front seal and look for the 2 tabs that would engage into the 2 notches in the converter. You can take a thin long screwdriver to reach in and see how it turns.

 

Finally got time to drop the trans and guess what I messed up from the start or this might be the reason the previous owner yanked the motor and left the trans. Both tangs are broke off the pump so it looks like I'm gonna just put a pump in the trans. It chewed up the torque converter some I guess with the broken prices rubbing the outside of it. I think its still use able tho but how should I go about flushing the converter? Anything I need to know before I pull the pump out/

 

Here's the broken pump drive tangs and the converter its got a little groove right near the drive slot in the converter but its not to bad think I need to replace it or just clean it out real good and take a file to the burr on it? Also anyone know if all the 400 turbo pumps are the sane?

 

Did you get a manual ? I would start with a way to hold the tranny on its end. Then take a measurement from the engine side of the bell housing down to the input shaft (and record it) then you should look in the manual to get an idea of what you are up against.

Sorry I should have said that I would cap it off and pressure wash it then pot it on the stand.