95 blazer 4x4 4.3; seal went out while my wife was driving, ran it dry, but it still shifted into 1 and 2nd. i bought a used trans, which was identical but now i have no gears at all. I have checked to make sure flex plate is on right, pulled a radiator cooling line to make sure front mount pump working. when i installed, i had to pull the converter back out about a quarter inch to bolt to flexplate. i have run it to check the fluid. all these things check out. i hear a whirring noise no matter what gear i have it in, but the vehicle does not move. any ideas?

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are you sure the used trans was in working order ?

 

not positive but it was guaranteed

 

If you hear a whirling sound more than likely the pump is bad. This sound is the same as a power steering pump low on fluid. The good thing is the pump is the first thing to come out of the transmission. It is not so hard to repair a pump. Here is the thing about transmissions. Don't cut corners!!! You don't want to have to take it out and put it back in more than once. If the sound is more like a gear not meshing and it is slightly grinding your sun shell is toast and you are going to need a full rebuild.

 

i had assumed the pump was ok because when i disconnected the line going into the radiator and started the engine, i had atf pouring out. wouldn't this mean the pump was working?

 

Hmmm I read it's possible for the transfer case to be in neutral. Pretty sure you could find that out by seeing if it rolls while in park.

Otherwise, all you determine with the disconnected cooling line is that the pump is turning.

 

first rule of thumb when buying a transmission from a junkyard is drop the pan. for whatever reason around here they love removing the filters out of them, i have no idea why. actually last one i did was on a dodge caravan, not only was the filter stolen out of it, there was a bunch of little rocks inside the pan, probably being kicked in there through the dipstick hole being exposed

its warrantied but it sucks if you have to remove it and install another one

 

yeah, its a pia to pull it out again. but i did take off the pan and changed the fluid and the filter. all looked ok in there

 

A broken sun shell will only affect reverse,2nd and 4th. And honestly you can change it faster than splitting the pump in half and rebuilding/aligning it. I would double check that the t-case is in gear as that is pretty common it gets knocked around while pulling trans. Usually grinds when returning to park if tcase is in nuetral too. Is the convertor the same as came with the used unit? checking for oil level difference between having the vehicle off and running is a good pump check without having to pull a cooler line (should be lower with engine running). I would pull a pressure tap and put a gauge on it first if you have one, But I'm betting the pump got destroyed on install and yes it will still flow cooler sometimes when the rotor is broken, or it pushes away from the lugs as it trys to build pressure. I'm assuming the shifter linkage has been checked?

 

ahhh! i never thought about the t case being in neutral , and it does grind a little going into park. i will check it tomorrow and post back. thanks to all trying to help.