Author Topic: Leak from behind torque converter  (Read 5546 times)

Offline cwest

  • Registered Users
  • *
  • Posts: 100
  • Newbie
Leak from behind torque converter
« on: April 14, 2014, 11:09:01 am »
I'm in the process of doing an auto to manual swap on my 86' K20 4X4.  To get the TH400 down I rigged up a normal floor jack with a couple tie-downs and then just lowered it.  Everything went great until I got the thing all the way down and went to pull it off of the jack.  The trans teetered forward and slid down off the jack landing on the torque converter with a little force.  At that point fluid started flowing from behind the converter.  It continued to leak too (much slower) once I got it resting level on the pan.  Can I assume I busted a seal behind the converter?  I'm hoping the case itself didn't crack, but those things are cast iron, right?  I don't see any bolts on the outside of the converter to take it off and check things.  Do I have to take the pan off and go at it from the inside?  It's a great running trans and I'd like to sell the thing is the only reason I care!  Thanks for any input       
86' Chevy K20
350/SM465/np208

08' Silverado 1500 4X4 WT

Offline BADAZ chevy guy

  • Registered Users
  • *
  • Posts: 235
  • Chevy! My drug of choice!
Re: Leak from behind torque converter
« Reply #1 on: April 14, 2014, 11:17:00 am »
The torc converter just slides onto the front shaft of the transmission. There are no bolts.

Offline Engineer

  • Senior Member
  • ****
  • Posts: 1402
Re: Leak from behind torque converter
« Reply #2 on: April 14, 2014, 11:19:56 am »
The torque converter just slides off of the main shaft.

Pull the torque converter out and you'll see what I mean.

Push it back in to stop the leaking.

Remember that both splines, and the ears on the front pump must be lined up before reinstalling the transmission. If you don't get the two notches lined up on the pump drive you will bust the transmission case at the bolt bosses when you try to tighten the bell housing bolts.
2002 Chevy 2500HD 4x4 8.1/ZF6sp RC/LB
2001 Chevy 2500HD 4x4 6.0/4L85E EC/SB
1997 Chevy Blazer 4x4
1994 Chevy K-2500 4x4 C6P 5.7/4L80E
1979 Chevy K-30 4x4 4sp 4.10
1977 Chevy K-30 4x4 4sp 4.10 454

Dad of an Eagle Scout, and a Life Scout

Offline cwest

  • Registered Users
  • *
  • Posts: 100
  • Newbie
Re: Leak from behind torque converter
« Reply #3 on: April 14, 2014, 12:40:24 pm »
Well that was easier than expected, and slightly embarrassing..  Can you tell I've never laid hands on an auto trans before?  Thanks for the info
86' Chevy K20
350/SM465/np208

08' Silverado 1500 4X4 WT

Offline BADAZ chevy guy

  • Registered Users
  • *
  • Posts: 235
  • Chevy! My drug of choice!
Re: Leak from behind torque converter
« Reply #4 on: April 14, 2014, 12:52:32 pm »
Well that was easier than expected, and slightly embarrassing..  Can you tell I've never laid hands on an auto trans before?  Thanks for the info

Done ever feel embarrassed. We all started someplace. For me it was sitting under the hood of my dad's 52 BelAir.

Offline LeftysRodandCustom

  • Newbie
  • Posts: 72
  • Newbie
Re: Leak from behind torque converter
« Reply #5 on: April 15, 2014, 01:37:55 pm »
He's right, you could never know without being taught. Some things are way simpler than you'd think though lol

Offline cwest

  • Registered Users
  • *
  • Posts: 100
  • Newbie
Re: Leak from behind torque converter
« Reply #6 on: April 16, 2014, 12:01:14 pm »
Thanks for the encouragement, gents!  Just so nobody has to go back and reread.. I'm doing an auto to manual swap and just got the auto out.  The trans cooler lines were seized in there pretty well, and in a bad spot for getting any leverage on them with a wrench, so I just cut the lines before I dropped the trans out.  Anyway, what should I do with the open lines now running into the radiator?   If I take them out of the radiator all together do they make caps or plugs to close off those ports, or are they fine just open to air since there won't be any fluid running through them now?           
86' Chevy K20
350/SM465/np208

08' Silverado 1500 4X4 WT

Offline Dan75k20

  • Frequent Member
  • **
  • Posts: 269
  • Newbie
Re: Leak from behind torque converter
« Reply #7 on: April 16, 2014, 01:30:25 pm »
You can find pipe plugs the same diameter as the fittings at a hardware store or auto parts store

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6600
Re: Leak from behind torque converter
« Reply #8 on: April 16, 2014, 02:18:15 pm »
Seal the trans wet cooler using 1/2 x 20 inverted flare fittings - don't use pipe plugs.  Seal the cooler to keep it clean in case you ever decide to reuse it.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline BADAZ chevy guy

  • Registered Users
  • *
  • Posts: 235
  • Chevy! My drug of choice!
Re: Leak from behind torque converter
« Reply #9 on: April 16, 2014, 03:11:28 pm »
YES! Flare fittings, NOT pipe plugs. They are different threads.

Offline cwest

  • Registered Users
  • *
  • Posts: 100
  • Newbie
Re: Leak from behind torque converter
« Reply #10 on: April 23, 2014, 03:37:30 pm »
Good knowledge on the 1/2-20 flair fittings, gents, they fit like a glove!
86' Chevy K20
350/SM465/np208

08' Silverado 1500 4X4 WT