[jak327]

what is the easiest way to replace a flex plate on a 79 chevy truck? should i pull the engine or tranny/transfer case. chevy 350/th350/np205

and how is the torque converter attached to the engine?

i have never pulled a automatic engine or tranny before so i dont know what im getting into.

thanks for the help

[junior stocker]

WOW, that is a can of worms no matter which way you go. I would think, as far as the trans/transfer case goes, it also means having to unbolt everything connected to the trans/transfer case. That means 2 drive lines, trans/tranfer case mounts, speedo drive, engine to trans bolts and flexplate bolts (3), kickdown/throttle valve linkage, shifter linkage, vacuum modulator line, possibly some electrical, then having a large enough trans jack to slide the whole unit back/down. The engine would mean exhaust, motor mounts, electrical, cooling, removing the radiator, fan, possibly starter, power steering pump, then separating the engine from the trans. The flexplate could be swapped out while the engine hung on a hoist, and not be removed from the truck. IF it were me, I'd probably go with moving the engine. Still a lot of work, for a simple part.

[EOD Guy]

IMO much easier to drop the tranny/Xfer case

[poncho62]

If you have access to a big stable floor jack, I would undo the torque converter, drive shafts, cross member, shifters and then just move the tranny/transfer case back enough to get at the flex plate....might have to lower it a bit.

[redsdad]

What Poncho said.

[LATECH]

remove the torque converter bolts and the bell housing bolts. Then put 2 bolts about 2 1/2 or 3 inches long in the lower housing holes unbolt the whole mess from the tranny mount and lift it with a floor jack to clear the mount and slide the whole mess back about an inch and a half.remember to push the torque converter in the trans. When you get to this point put a wrench on the crank bolts for the flex plate and knock them loose by striking wrench with a hammer. Then you can slide your hands up in side flatways and work the bolts out. get all six out, drop and swap the plate .bolt it back with a little blue loctice and slide the whole mess back together.
I have changed them this way when i worked at chevrolet(another tech shared the trick with me) and have been doing it that way for years. you dont even have to unhook the tranny lines, they are flexible enough to move that far. Its a tight manuever but very do-able. And you dont need a tranny jack and also it is pretty safe even for one guy.

[EOD Guy]

Nifty trick

[sbchevfreak]

Originally Posted by latech

remove the torque converter bolts and the bell housing bolts. Then put 2 bolts about 2 1/2 or 3 inches long in the lower housing holes unbolt the whole mess from the tranny mount and lift it with a floor jack to clear the mount and slide the whole mess back about an inch and a half.remember to push the torque converter in the trans. When you get to this point put a wrench on the crank bolts for the flex plate and knock them loose by striking wrench with a hammer. Then you can slide your hands up in side flatways and work the bolts out. get all six out, drop and swap the plate .bolt it back with a little blue loctice and slide the whole mess back together.
I have changed them this way when i worked at chevrolet(another tech shared the trick with me) and have been doing it that way for years. you dont even have to unhook the tranny lines, they are flexible enough to move that far. Its a tight manuever but very do-able. And you dont need a tranny jack and also it is pretty safe even for one guy.

X2. I have done it much the same way, except on a hoist, as I hate laying on the ground to work.

[LATECH]

Originally Posted by sbchevfreak

X2. I have done it much the same way, except on a hoist, as I hate laying on the ground to work.

Yeah me too. It is easier with a lift. But it works well on the ground if need be and if you are doing it alone(like myself usually) it is safer because you dont risk dropping the trans on your arm or hand or head.

[jak327]

thanks for trick latech! that saved me a ton of time. i only had to pull the tranny back about an inch to get the flexplate bolts out. and the new flexplate went in just as easy as the old one came out. i did use the blue locktight on the flexplate bolts and torque converter bolts since they were just barely snug when i took them off.

the only hard part was the top two bolts holding the tranny to the engine. i have an hei dizzy and alot of wires back there so it made it very time consuming to get them out and back in. probably would have been faster to pull the distributor.

thanks for the help again. it was very much appreciated