The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 07-03-2024, 06:07 PM   #1
RedBed
Registered User
 
RedBed's Avatar
 
Join Date: Apr 2017
Location: TX
Posts: 257
never ending leak - transmission

Where the transmission meets the driveshaft I have a leak that will not be fixed. Had the seal replaced twice. No luck.

And it doesn't leak constantly. It will be fine for a while, then I will come out one day and there will be a 16oz puddle under it.

I do not drive it often which makes it weirder.
__________________
1979 Chevrolet Bonanza/305/4L60/Edelbrock Performer/Holley 600 Classic
RedBed is offline   Reply With Quote
Old 07-03-2024, 06:24 PM   #2
Getter-Done
Senior Member
 
Getter-Done's Avatar
 
Join Date: Dec 2009
Location: TN.
Posts: 8,329
Re: never ending leak - transmission

The driveshaft yoke and rear bushing are probably worn cause your leak.

Is this a 4L60 transmission in your signature?
__________________
________________________________________________________________________________________
____________________________________________
84 Chevy K-20
63 Impala (my high school car)


http://67-72chevytrucks.com/vboard/s...Crew Cab Build
Getter-Done is offline   Reply With Quote
Old 07-03-2024, 07:09 PM   #3
RedBed
Registered User
 
RedBed's Avatar
 
Join Date: Apr 2017
Location: TX
Posts: 257
Re: never ending leak - transmission

Quote:
Originally Posted by Getter-Done View Post
...Is this a 4L60 transmission in your signature?
It is.
__________________
1979 Chevrolet Bonanza/305/4L60/Edelbrock Performer/Holley 600 Classic
RedBed is offline   Reply With Quote
Old 07-03-2024, 10:35 PM   #4
400/400
Registered User
 
Join Date: Sep 2014
Location: Central MN
Posts: 288
Re: never ending leak - transmission

Certainly sounds like a tail shaft bushing. Also check that the u-joints are in good shape.
__________________
-400/400
1979 K25 350/SM465/205/44HD/14FF
1985 K20 400/400/208/10/14
1987 V10 TBI350/700R4/208/10/10
'85 Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=643968
400/400 is offline   Reply With Quote
Old 07-04-2024, 05:57 AM   #5
Dead Parrot
Registered User
 
Join Date: Aug 2012
Location: Oklahoma City, OK
Posts: 2,588
Re: never ending leak - transmission

Not sure about the 4L60 but my TH350 had a similar problem. After replacing the tail shaft seal did nothing to fix the leak, further investigation revealed that there is an inner rear seal that also needs replacing. After having that replaced, no more leak.
Dead Parrot is offline   Reply With Quote
Old 07-06-2024, 10:18 AM   #6
Axle
Registered User
 
Axle's Avatar
 
Join Date: Jul 2011
Location: SW Ontario
Posts: 1,208
Re: never ending leak - transmission

Had the tailshaft off the trans? Theres a cup and oring to help keep oil from getting out the tailshaft yoke vent hole. Mine is plugged with rtv to stop the drip.
Axle is offline   Reply With Quote
Old 07-06-2024, 05:32 PM   #7
RedBed
Registered User
 
RedBed's Avatar
 
Join Date: Apr 2017
Location: TX
Posts: 257
Re: never ending leak - transmission

Thank you for all the replies!
__________________
1979 Chevrolet Bonanza/305/4L60/Edelbrock Performer/Holley 600 Classic
RedBed is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 12:25 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com