New Tranny Problem PLz help

[78 K-10]

1978 chevy 1/2ton. 4x4 small block 350 (newly installed 400 tc) (automatic...) thm350 np203 transfer case

So I just finished installing a "completely" rebuilt tranny from a local guy( Here is hood river 97031). I
finished all the install and little stuff. I didnt have a whole lot of space between converter and flexplate
but Im so damn sure it was seated properly. I put 5 quarts in tranny cranked engine and quickly dumped 5 more


then checked it. I added another quart then I went to shift the column down from park. it seemed like the shifter
mechanism shifted just like it used to but maybe the tranny wasnt doing anything although the L1 at the bottom
seemed to make the truck lurch a teeny bit. when I started going back up the tree when I went from reverse to park
it did this horrible sound of like starter sound(squeal) plus metal chewing. I immediately turned it off so I dont know if it "might" have gone away or if it was normal for freshly rebuilt tranny. But I know it didnt all seem right...So my question to you is does it sound like
something you've seen before?

isnt is around 11.8 quarts for completely empty thm350 and half full tc?

btw the bellhousing is supposeddly only reused thing the guy said. and supposeddly new 400tc

I do have an aftermarket cam... pretty mild I think.

cheyne

 

[f1shman]

Both driveshafts installed in the truck?

 

[RetroC10Sport]

Both driveshafts installed in the truck?

This.

 

[HotRodPC]

oh man. Its sounding to me like you don't have the conveter seated over the pump lugs. All the things you mention are signs of that. You might be able to loosen your bellhousing bolts to buy some space between the converter and flexplate to give you some room to manipulate the converter over the pump lugs. There should be at least an inch, probably closer to 1 1/2 inch between the conveter and flywheel if the conveter is pushed all the way back into the pump gears. Then pull the coveter to the flexplate and bolt it up.

 

[HotRodPC]

and 1 other thing. Are you sure you got the right converter for the trans. There is Th350 and Th350C, the C model being the lock up conveter. They WILL NOT interchange. If you have a NON lock up conveter with a Lock up trans, or vice versa, you can get thise screeching noises you speak of. I still think its that you didn't get the conveter over the lugs though. The only little moveemnt you're geting is the conveter snout, pinching or pinned against the pump gear, not interlocked in the lugs of the pump gears as need to be.


And I assume 400tc, is a Th 400 Torque Conveter??? If that is true, that is fine. Th400 and Th350 torque converters interchange. But a Th400 TC will NOT work on a Th350C lock up trans. So make sure you don't have an electrical plug in on the driver side over the pan. IF you do, its a Th350C and you have the wrong conveter. Having the wrong converter might explain why it won't go all the way on too, if that's the case. Just be sure.

 

[78 K-10]

yes driveshafts both put back on

 

[towman]

sounds like the transfer case is not engaged properly, that is why you are getting the noise while going back into park

 

[78 K-10]

got it

I had the transfer case in neutral. So its all figured out. Anyone know how to Properly adjust the np203 shifter levers? and how do I adjust them to make the shifting up smoother? just mess with it? or something to look for?

 

[Swims350]

last I knew 12 quarts to completely fill the trans and converter, you did dump at least a quart or 2 in the converter before putting it in did you?

Also HRPC, uyuummm I think you mean an inch to 1-1/2 between the bellhousing flange and TC feet/mount pads, not 1-1/2 inches between the flywheel and converter, unless that's how far apart the motor and trans are lol. Most room I ever had between the flexplate and converter fully seated was like a good 1/4 inch or so.

 

[HotRodPC]

last I knew 12 quarts to completely fill the trans and converter, you did dump at least a quart or 2 in the converter before putting it in did you?

Also HRPC, uyuummm I think you mean an inch to 1-1/2 between the bellhousing flange and TC feet/mount pads, not 1-1/2 inches between the flywheel and converter, unless that's how far apart the motor and trans are lol. Most room I ever had between the flexplate and converter fully seated was like a good 1/4 inch or so.

Yes, I was thinking more of the bellhousing flange, before he started the install. But still 1/4 is pretty tight too. If you have to pull the converter forward 1/2 inch or so, that is still all good. It depends alot on the conveter snout. Of course at worst even with long cut lugs on the converter snout, it will bottom out on the pump gear. Then you pull it forward to the flexplate and its off the pump gear.

Glad you got that figured out. I wasn't even thinking of the Tcase.