Th350 problems after engine swap

[Heyzeuscristos]

So i just had to swap a 350 in my 77 k10 due to previous owners negligence. I finally got the engine tuned up right and now im having issues with the transmission. The transmission wont shift into any gears. The linkage is good, both internal and external. I managed to coax it into drive by putting it in gear and increasing the throttle until it caught, but it wouldnt stay in gear for long. I have already checked the fluid and changed the filter and it all checks out there. I am just at a loss as to what the problem could be. Someone told me i need to either get a new one or get it rebuilt but im trying everything i can to keep it from getting to that point. Any advice or help would be greatly appreciated.

 

[RangRayy]

So i just had to swap a 350 in my 77 k10 due to previous owners negligence. I finally got the engine tuned up right and now im having issues with the transmission. The transmission wont shift into any gears. The linkage is good, both internal and external. I managed to coax it into drive by putting it in gear and increasing the throttle until it caught, but it wouldnt stay in gear for long. I have already checked the fluid and changed the filter and it all checks out there. I am just at a loss as to what the problem could be. Someone told me i need to either get a new one or get it rebuilt but im trying everything i can to keep it from getting to that point. Any advice or help would be greatly appreciated.

Same happened to my '87 ended up being the fluid level was low. Cold the fluid was in the half mark. It after warming up there was nothing on the dipstick. Probably doesn't matter since it just controls shift points but make sure he vacuum modulator is hooked up.

 

[Heyzeuscristos]

So the fluid is reading full, but i only ran it for about 20 minutes after i changed out the filter and fluid. The modulator is hooked up to full time vacuum on the intake. The weird thing is the fluid level didnt change after running it for a while, not sure if it should or not because i havent had to mess with transmissions much. Ill try letting it run for a while tomorrow and see if the level changes

 

[crazy4offroad]

If it doesn't do anything in any gear including reverse and the fluid didnt look dirty when you changed it, it may have leaking seals in the pump.

 

[Rusty Nail]

Idling in park is ineffective. Use REVERSE to force the pump's operation and circulate fluid.
Check dipstick.
Then hold in it each gear for a 10 seconds or so.
Check dipstick.

Report.

 

[Heyzeuscristos]

Idling in park is ineffective. Use REVERSE to force the pump's operation and circulate fluid.
Check dipstick.
Then hold in it each gear for a 10 seconds or so.
Check dipstick.

Report.

So after not having time to mess with it last week i just did as you suggested. I put the truck into reverse with the parking brake set in case the tranny catches and i let it run for about 15 minutes and checked the stick and there was no change. Shifted through the gears and same deal, no change and no response from the tranny.

 

[Rusty Nail]

Ruh Roh Raggy!

That sounds pritty bad dude. We are that the end of my automatic transmission knowledge.
Well, except that I know they are magical sources of automotive wonderment.
They has clutches, and bands, and fluid, and stuff and things!

My next move would be to whack it with a hammer, not sure I would listen to me.

I know HEAT is the #1 killer of automatic transmissions.
I know that reverse forces the pump to operate without the driveshaft turning, and I know the torque converter is what turns the pump.
SO!
If the pump isn't turning, the other option is that the convertor must not be fully seated.
Can you see it spinning? Did it come out / slip off during motor R&R? It is EASY to install them improperly.

I'm no more help than that man, best wishes.
Allow me to defer to some other members that MAY know more about automatic transmissions than I.

P.S. don't use a very big hammer, transmissions are sensitive.

 

[Heyzeuscristos]

Yeah we are out of my realm too haha. I actually pulled the converter off when i did the swap and made sure it still had fluid in it and everything. Pretty sure i put it back on right because it drove afterwards. I think this tranny was just beat to hell like the old engine was. Problem is it looks brand new inside. I had a couple shavings in the fluid but nothing too crazy. But when i first got the truck the tv cable wasnt hooked up and neither was the modulator. No idea how the dude that had it before me was driving it with all the late/hard shifts

 

[74 Shortbed]

The weird thing is the fluid level didnt change after running it for a while, not sure if it should or not

Don't know how I missed this!!. The fluid level is way up above the pan rail when it isn't running, when it's running and fluid is circulating the level drops and should be no more than the full mark(I prefer mid way between the Add and Full)if the level stays the same when running(way up the stick)then the pump in not working or the converter is not engaged in the pump, are you getting any kind of whining when it's running..

 

[Heyzeuscristos]

No strange noises from the tranny when its running. It acts like normal except it wont shift.

 

[74 Shortbed]

First thing I would do is unbolt the converter and see it you can slide it back, if it won't slide back it's not engaged in the pump.

 

[bucket]

Or did the converter bolts come loose and fall out?

 

[74 Shortbed]

Or was it even bolted up to begin with, friend of mine did that once being in a hurry, lol..

 

[bucket]

Or was it even bolted up to begin with, friend of mine did that once being in a hurry, lol..

Once isn't bad. I know a guy that did that several times... he's not a mechanic any more thank goodness.

 

[Heyzeuscristos]

Either i dreamed how much of a pain they were to put on or theyre on there haha. No i made sure its still bolted up and everything is tight