Hot Rod Forum : Hotrodders Bulletin Board

Hot Rod Forum : Hotrodders Bulletin Board (
-   Transmission - Rearend (
-   -   Th 350 Leaking from tailshaft vent??? (

Vegaguy 06-14-2008 10:55 PM

Th 350 Leaking from tailshaft vent???
Hi everyone, here's my problem. I have a th350 behind a sb 350 in a vega. The trans has the short tailshaft. It always pukes out the tailshaft vent for some reason. I had it on stands running in gear and sure enough it coming out. I removed the tail housing and everything looks ok. It keeps leaking out until its to low to run and starts slipping. I rebuilt this tranny myself. It was my first th350 but not my first rebuild. Did I miss something? I dont have a clue why its leaking out of the vent. Any help would be greatly appreciated. Thanks in advance for any help.

C-10 06-15-2008 01:08 AM

Tail shaft vent?

Are you referring to that round piece if tin pressed in the backside of the yoke with a hole in the center?

The only vent that is supposed to be in this trans is on the very top of the case about halfway back.

I've welded the caps in the yokes before, as well as the pin hole in the center. Usually the yoke has a missing spline to vent any fluid back into the extension housing.

Some output shafts have a pressed on 'can' with an o-ring to seal the yoke that way.

If you totally degrease the cap and the the surrounding areas on the yoke, I bet one could use JB weld to seal it. Never tried it, but it may work. :thumbup:

Vegaguy 06-15-2008 02:21 AM

Its a plastic pressed in tube on the top of the tailshaft housing. Its not the yoke. I'll try and see if I can get a good pic of it and post it tomorrow since its up on stands right now, but thanks for the reply.

Vegaguy 06-15-2008 05:52 PM

2 Attachment(s)
Here is the vent i'm talking about. Can I plug this vent without blowing out seal or something. There is still the vent on top of the case. I'm tired of loosing all my tranny fluid all the time. :confused:

C-10 06-15-2008 06:48 PM

There SHOULD be a passage from the main case into the ext. housing, thus allowing the tail to be vented into the main case. If you pop off the tail housing and there is, I would go ahead and plug the tail vent.

That's a weird leak, are you sure you are not over full?

Vegaguy 06-15-2008 06:51 PM

Not over full, if I drive it enough it will leak untill the fluid is to low to drive. Going around the slightest curves the fluid goes to the side away from the pickup and feels like nuetral. Inside the housing the vent tube is curved and about 1 1/2" long.

C-10 06-15-2008 11:14 PM


Originally Posted by Vegaguy
Inside the housing the vent tube is curved and about 1 1/2" long.

But this is the one you wish to plug?

I mean if the tail is not sealed from the rest of the case, go ahead and plug the tail vent. The extension housing and the case will now basically share the same case vent.

All times are GMT -6. The time now is 04:23 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.