Th400 won't budge after engine rebuild
 

I have a 1970 C 10 with a freshly rebuilt 350 and turbo 400 transmission that was running and shifting perfectly before I pulled the motor out. I got the motor back in and bolted to the transmission with a new 2500rpm stall converter, new adjustable shift modulator, Derale deep trans pan and new trans filter. Also installed new B&M light truck megashifter and all linkage.

Here's the problem, when I started the truck to back out of the garage, I put it in reverse and nothing happened. No think, no rpm drop, and nothing when I gave it gas. Tried every gear, nothing.

Now, when I put the stall converter in, I put a quart of fluid in it and slid it on until I felt a nice thunk, rotated it and felt another as it slid even further on. When I bolted it to the flexplate, it had to slide out towards the engine a bit to bolt on, just like it's supposed to.

Here's the part that concerns me. The Derale deep pan holds 3 1/2 quarts more than stock, so the pan is fairly deep. It came with a filter extension to compensate for this. With the stock pan, the filter sat flat (parallel to the trans and ground) when it was on properly and bolted to the bottom of the trans with a single filter bolt. With the deeper pan and new filter extension, when the filter was installed, to get it to bolt up like the stock one it had to be tilted at an angle ( not flat or parallel to the transmission at all ) in order for the filter bolt to thread into the transmission. I can't see putting a trans filter in and not using the bolt. That would mean the filter is just hanging there by the filter extension.

Any thought on this filter thing OR why my th400 won't budge? It worked great before the motor came out. I checked the fluid while it was running and in park, shows fine on the dipstick. Fluid is nice clean red in color.

Re: Th400 won't budge after engine rebuild
 

I think you said that the converter engagement seemed normal - I just want to be doubly sure you didn't "pull the motor and trans together" with the bellhousing bolts - it should have all mated up properly without -needing- the bolts to pull it together. If the pump isn't engaged it's not going anywhere, so it's gotta be either the pump or the pickup I think.

You put the driveshaft back in right? (sorry, couldn't resist)

Re: Th400 won't budge after engine rebuild
 

Quote: "I checked the fluid while it was running and in park, shows fine on the dipstick.."

I'm not familiar with the TH400; but my TH350 calls for checking the fluid level in drive after selecting each gear for 15-20 seconds to make sure all valve passages have fluid..

I can't picture the filter extension situation and have never seen one..

Slots in the pump drive snout of the converter may not be engaged in the pump and the splines on the input shaft and the splines on the stator shaft may not be lined up?

Here is PATC's instructions page 2; I thought it was better written than the B&M version.

Re: Th400 won't budge after engine rebuild
 

Sounds like the pump is suckng air!
Pull the pan off and see if the filter is up in the hole and also check and see if you have the o-rings in place.
Then find the correct length shoulder bolt/extension to support the filter in a lever position.
Mike.:chevy:

Re: Th400 won't budge after engine rebuild
 

my first thought is the orange O-ring that goes on the pick up tube of the filter. If that O-ring isn't there you have problems just as you have described. The thing to do might be get a gauge and take a line pressure reading. I'm just throwing that out there I know the newer ones are very susceptible to line pressure problems. The pressure gauge would at least let you know if your pump is working or if your pressure is low then look at the filter O-ring thing.

Re: Th400 won't budge after engine rebuild
 

No I put them together before bolting anything up. Is the pickup part of the filter? The filter angle is really weird to me

Re: Th400 won't budge after engine rebuild
 

I was thinking this too, why wouldn't the pan kit come with a longer bolt and spacer or something if it had a longer filter extension? Could it be that the filter just hangs from the extension and sits on the air cooling tubes in the bottom of the new pan?

Re: Th400 won't budge after engine rebuild
 

So glad I got a pan with drain plug this time lol but DANG do I wanna drive it!!!!

Re: Th400 won't budge after engine rebuild
 

I'm going to take these measurements before I remove the pan, but I'm 99.99999% positive I installed converter right. Thanks guys for the help

Re: Th400 won't budge after engine rebuild
 

No instructions with new pan and I can't find anything about installation and what people do with the filter, weird

Re: Th400 won't budge after engine rebuild
 

I was wondering if you got a longer dip stick since you have a deeper pan now maybe not enough fluid? Just a guess.

Re: Th400 won't budge after engine rebuild
 

I have deep pans on several trucks and all of them have a separate extension piece for the extra length so you can use the standard filter.
The dipstick reads the same regardless of the pans depth.A deep pan adds more fluid,but doesn't change the correct level needed to work.
The deep pan kits usually have a short tube or sleeve and longer screw to make up the difference in length.
If you are missing an o-ring,it will suck air because the o-ring is above the fuid level.
Mike.:chevy:

Re: Th400 won't budge after engine rebuild
 

WELL......took the pan off and filter off, removed the new extended filter pickup and read on one end "pickup" and the other end "filter"....I had it backwards and bolted the filter to the valve body which doesn't work with a longer tube. Im putting it back together now so we'll see

Re: Th400 won't budge after engine rebuild
 

Hopefully this will (or did) fix your problem. It sounds like the converter isn't filling with trans fluid. Be sure to check the fluid level several times after you make your "repair" and run the trans through the gears with the engine running as mentioned above. The convertor will probably take a few more quarts to fill once the fluid starts pumping.

Re: Th400 won't budge after engine rebuild
 

Problem SOLVED. Goin on the maiden voyage baby!!!

Re: Th400 won't budge after engine rebuild
 

how many quarts of tranny fluid did you put in?/ you know it takes about 10-14quarts total for it to run right right??

Re: Th400 won't budge after engine rebuild
 

Pickup tube was upside down. I put the parking brake on and let each gear have 20 seconds, then topped it off til it read full on the dipstick. Runs great now

Re: Th400 won't budge after engine rebuild
 

This is just to give props to 100% Chevy for being right on with his advice... frankly as soon as I read his analysis I knew that it sounded more plausible than the best that I was able come up with at the time.

Wisdom often comes from hard knocks (for me anyway) and the difference between good and bad advice is often hard to see unless in hindsight. Anyway I'll be listening next time 100%Chevy weighs in! Way to go Bro!

Re: Th400 won't budge after engine rebuild
 

Your welcome and thanks for the praise!
The only way to gain experience is to screw up!
And,I'm one of the best!
Mike.:chevy:

Re: Th400 won't budge after engine rebuild
 

Yes thank you 100%, guys like you make this site what it is man