So I let myself get in a rush last night getting the newly rebuilt TH400 bolted up to my 327 for my 30 coupe and made the mistake of not having the torque converter seated...the crank wouldn't turn after install into the car so assuming that's what happened. Newly rebuilt TH400 so frustrating but I'm not a transmission guy. I know I could have messed up the pump; is there any visual indicators that I messed it up? Trying to see what I should be looking for when I take it all back apart tonight and really hoping I didn't mess anything up. Any chance it's fine and could just need to be re seated? The bellhousing bolts were a little harder to get on than I should have allowed but that's what I get for rushing a job I guess. Thanks for any insight.
Did that once with a TH350 and broke the pump. I don't think there is any way to see without taking the pump cover off. You might try getting the torque converter lined up and see if it feel odd. Otherwise, pull the pump cover off and have a look.
Based on your scenario, either the converter was not seated all the way, or the pump gear was installed backwards during the rebuild. Most likely the pump is broken.
In my limited experience, when sliding and wiggling and wobbling the converter around into the front of the trans, unless you've mashed at least a couple of your fingers between the converter and the bell housing it's not properly installed. Pain is verification!
I hold the pilot and one lug, so I don't squish my fingers...but I do like to measure the distance from block to flexplate, and compare with a measurement from face of transmission case to mounting lug, to make sure it's seated before installing the transmission, if it didn't feel like it went in all the way.
A good rule of thumb is that if you can get your fingers between the side/rear of the convertor an the bell housing, it isn't in all the way. As you are installing the convertor you have to line up three things, the input shaft splines, the stator support splins and the pump drive. If you bolted the transmission bell to the block and pulled it tight, it's about a 99% certainty that you damaged the front pump.
I'm going to assume I have ruined the pump...for now I'm just going to leave the motor in the car while I get the floors done and deal with the trans down the road. I'm pissed at myself so time to tackle other parts of the build for now. Thanks for the advice everyone and I'll be sure to post pics once I pull it back out
One school of thought is it may not be totally your fault. If your rebuilder installed the pump gear backwards it would not allow the converter to seat back far enough. Pulling the transmission and shining a flashlight into the front seal area would confirm it by looking at the pump gear. The two drive tangs on the gear should face away from the converter. If backwards your rebuilder may make it good if you don't delay too long.
Pull the converter. Take a dental pick or very small screwdriver and carefully go in between the seal and stator. You should see two tabs on the small pump gear. Try to turn the pump gears with the pick. They should turn smoothly.
One thing I didn’t notice, was your transmission install method. Ie was the converter bolted to the flex plate, the transmission drawn into the block with the BH bolts? Or?
I've had the backwards pump thing happen. I've also broken a pump by not having the converter properly engaged In my case I head a loud crack when the trans. started to tighten up against the block. I've seen a couple where the engine wouldn't turn over when the trans. was bolted up, but after alignment, the pump was fine. Seems the flex plate allowed enough give to forgive..? Might check the plate also, it may be tweaked now. Good luck!
If you put it off until later, there is always the chance that when you finish all the other things that you will forget to fix this.
When installing a torque converter, you should hear/feel 3 distinct clunks. First will be the input shaft engagement, second with be the stator engaging the stator support on the front pump, and the third clunck will be the flats on the converter snout engaging the front pump. If you don't hear/feel each on them then stop and reinstall converter. Also don't forget to apply Vaseline on the snou I've seen the ruination of the garlock seal on the front pump because of the dry snout wiping out the lip of the seal on start up.
So I finally got it out and looking at it I don’t see any damage from the outside. Thinking of dropping it at the trans shop though to be safe. What do y’all think? The putter splined shaft doesn’t rotate though is that normal? The TC slides in nicely otherwise and no funny sounds when I turn it. Thanks!
I don’t see the ears on the pump gear. Can you look between the seal and the stator shaft and see the ears on the pump gear? Two tangs? Should be visible. Is so, take a small screwdriver or pick and see if you can turn it.
As said above need three distinct chunks when installing the converter . The first 400 I ever rebuilt i got the pump gear in backwards. It ran for about 300 miles had a whining noise . Shoved the gear into the pump to hard and ate the pump and then transmission. I'd pull the pump and inspect it. Lot cheaper now.
The picture appears to show that the pump gear is in backwards with a chip broken out of the drive tag. Since your shop put it together, take it back.
It's easy and cheap for a shop (or experienced trans. guy or gal) to pull and fix the pump assy on a T-400. Don't let it worry you too much.
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