How to replace driveshaft in trans?

[68 P.O.S.]

Getting ready to pull my engine (350) and trans (TH350) out for cleaning, resealing, etc. From what I've read here, the driveshaft will pull out of the trans as I remove the engine/trans. Sounds easy enough. When I reinstall the engine and trans, what's the best way to re-insert the driveshaft into the trans? This is my first time doing this and didn't find info on it. Thanks!

[gmc684x4]

Unbolt the drive shaft first
Not knowing your truck its either 1 or two peice setup remove it drain tranny before removal

Engine hoist I use most i separate engine from tranny

[Davidf]

Originally Posted by 68 P.O.S.

Getting ready to pull my engine (350) and trans (TH350) out for cleaning, resealing, etc. From what I've read here, the driveshaft will pull out of the trans as I remove the engine/trans. Sounds easy enough. When I reinstall the engine and trans, what's the best way to re-insert the driveshaft into the trans? This is my first time doing this and didn't find info on it. Thanks!

The driveshaft is connected to the transmission with a splined (slip) yoke. To remove the driveshaft, you simply unbolt u-joint from the rear axle input yoke, unbolt the center support bearing and then pull the driveshaft (complete with front u-joint/yoke) out of the transmission tailpiece. There is no bolt, clip, pin, or anything else to loosen or remove at the driveshaft/transmission connection. You reverse the process when reinstalling the driveshaft.

Little to no transmission fluid will escape when you remove the driveshaft (the fluid level is below the height of the tail shaft). But, if you tilt the transmission down at the rear, fluid will pour out. So, drain the fluid before removing the trans/engine assembly. And, tie a sturdy bag around the trans tail shaft to catch the residual oil that will want to escape even after draining the trans fluid.

[68 P.O.S.]

Originally Posted by gmc684x4

Unbolt the drive shaft first
Not knowing your truck its either 1 or two peice setup remove it drain tranny before removal

Engine hoist I use most i separate engine from tranny

Knew I forgot something lol. It's a 2-piece.

[68 P.O.S.]

Originally Posted by Davidf

The driveshaft is connected to the transmission with a splined (slip) yoke. To remove the driveshaft, you simply unbolt u-joint from the rear axle input yoke, unbolt the center support bearing and then pull the driveshaft (complete with front u-joint/yoke) out of the transmission tailpiece. There is no bolt, clip, pin, or anything else to loosen or remove at the driveshaft/transmission connection. You reverse the process when reinstalling the driveshaft.

Little to no transmission fluid will escape when you remove the driveshaft (the fluid level is below the height of the tail shaft). But, if you tilt the transmission down at the rear, fluid will pour out. So, drain the fluid before removing the trans/engine assembly. And, tie a sturdy bag around the trans tail shaft to catch the residual oil that will want toe scape even after draining the trans fluid.

Got it. I've removed the shaft from the diff before, so I get all that. The part I didn't understand is putting the engine & trans back in. It seems like it would be a bigger challenge getting the shaft back in the same way it came out. I wasn't sure if there was a trick to doing it, or if i would have to remove the shaft either way.

[Andy4639]

They make a plastic piece to go in the end of the transmission to hold the fluid in. You can buy them cheap and tape it to the transmission while it's being pulled. Good idea to have a bag also though.

When going back in have the drive shaft pulled off the rear end and center bearing. Once you have the motor & transmission sitting back in the truck just slip the shaft back in it and install it back to the rear end and center bearing.

https://www.summitracing.com/parts/p...caAmqSEALw_wcB

[54blackhornet]

You can’t beat the experience on this site.

[68 P.O.S.]

Thanks gents, I appreciate it. I'll let you know how it goes once I get to it lol. Should be soon

[BigBird05]

That plug will come in handy if your not planning on draining the transmission.