'''84 Chevy Blazer tranny converter (200R4) will not lockup. Can anyone help? Thx.

it really sounds like the torque converter is locking up, could be a lockup solenoid or the converter is starting to fail or failed, have a tranny shop check it out. Does it not go into reverse too? That would be a dead give away.

HAVE YOU DISCONNECTED THE TORQUE CONVERTER? SOMETIMES THE TRANS WILL BE STUCK TO THE BLOCK. YOU MAY HAVE TO TRY MOVING IT BY THE TAILSHAFT. SPRAY BLASTER (PENATRATING OIL) ON THE DOWEL PINS

Check the sensors on the transmission. May just be corrosion on the sensors or it may be a faulty sensor. Also, the torque converter bearing may have went bad due to the running it on low transmission fluid.

Could be bad torque converter.

Check fluid level when hot. If ok the flush cooling lines between tranny and radiator. Also check your modulator they are cheep from napa. Difficult for me to duplicate hissing sound on the computer but check your converter for how hot it is after twenty minutes. Last check the vacume line from manifold to modulator..sometimes a small hole can make that noise and effect shifting...hope this helps:)

It sounds more like the pump, if the converter fails it would have a crazy lock up shifting problem. Sometimes the bearing for the torque converter will loosen and spin in the housing this to could be the issue.

Your 84 wiring harness is for the TCC ( transmission converter control) system.
On the left side of the carburetor (driver side) you should have 2 cables, one for the accelerator and the 2nd for the TV (throttle valve) control. You will need to adjust the cable for correct shift points. Under normal circumstances you will have 7 to 10 mm's extending beyond the cable adjuster block.
Should take care of the issue for you.
Let me know.
Regards,

Yes, but the steps involved in switching the 4wd output shaft, over to the 2wd output shaft are very involved. Thats assuming that the bellhousings are identical. (detachable bellhousing) That you do not need a 30 spline input shaft for your torque converter (96+ blazer input shaft splines are all 28 splines, however you may need a 30 spline in order for the correct torque converter to fit your 2wd vehicle.) You will need to know what 2wd output shaft you need, there are quite a few variations. Then you would need to take the pan off, pull the shift soleniod blocking access to the lockup soleniod, remove the lockup soleniod, remove the pump bolts, pull the pump, unhook the 2nd/4th, band remove the reverse drum - 3/4 drum (by pulling the input shaft twards you) then remove the yellow snap ring holding the output shaft in place. Now the output shaft is able to be removed and switched. Re instalation of the drums/pump is tricky as well, as all the clutches need lined back up to slide back onto there corasponding splines. Long story short, it would be alot more trouble than its worth. : )

Yeah Go Buy The Repair Manual And A 24 Pack.

could be a bad lockup solenoid or a bad torque converter