|
03-26-2012, 11:16 PM
|
#1 |
|
Registered User
Join Date: Oct 2010
Location: Wallingford CT
Posts: 260
|
Tranny leak help
Today I decided it was time to find the source of my tranny leaks. It's a 71 C-20 402/400 that is my daily driver and a steady work in progress. So one leak is coming from the speedo cable area ? The other is coming from the vacuum operated piece on the pass side just above the pan? So it looks like that part is held on by a retainer clip and I was thinking of trying to take it out and maybe find an o ring but would like some guidance... Also what is the correct part name and should I replace it , it shifts fine so I am worried about replacing it and the tranny not being the same?
Posted via Mobile Device |
|
|
|
03-27-2012, 12:19 AM
|
#2 |
|
Registered User
Join Date: Sep 2000
Location: Gold Bar, WA
Posts: 1,216
|
Re: Tranny leak help
The vacuum thingy is the vauum modulator. before you get too crazy replacing the o ring on it...if there is one, I don't know for sure...pull the vacuum hos off it and make sure nothing leaks out from that. If atf comes out there, you will need to replace the modulator which might also come with the seal you need. I've never really tried removing that or the speedo cable housing so I don't know what's involved on trying to seal them up.
__________________
My Projects: 1960 GMC 1/2ton with 305 V6 (daily driver) 1963 Chevy 1/2ton 2wd...converting to 4x4 1967 Suburban 1/2ton 2wd My Girlfriends Projects 1985 Chevy Suburban 3/4ton 4x4 with 6.2L diesel, 4" lift, converted to TH-400, Warn Premium manual hubs, & Wildcat 315/75/R16 tires. (daily driver) 1978 Camaro Type LT with a Marine 350 & vortec heads, Rochester Carb, & roller cam 1978 Camaro Z28 |
|
|
|
|
03-27-2012, 06:46 AM
|
#3 |
|
Registered User
Join Date: Oct 2010
Location: Wallingford CT
Posts: 260
|
Re: Tranny leak help
Thanks, does anyone have a little more info ?
Posted via Mobile Device |
|
|
|
|
03-27-2012, 12:05 PM
|
#4 |
|
Registered User
Join Date: Nov 2011
Location: Idaho
Posts: 857
|
Re: Tranny leak help
Go back a few pages to find speedo cable leaking
Posted via Mobile Device |
|
|
|
|
03-27-2012, 12:41 PM
|
#5 |
|
454 MAKES IT ROAR
Join Date: Jan 2008
Location: Essex, U.K
Posts: 2,701
|
Re: Tranny leak help
I would replace the modulator, they're cheap and very easy to do and it will come with a nice new O ring (see pic)
There is another O ring on the speedo cable housing which may be the issue (see pic)
__________________
Nigel. An American living in a British body. 1971 Chevy Cheyenne 10 454 "In a time of universal deceit, telling the truth becomes a revolutionary act." - George Orwell "When injustice becomes law, resistance becomes duty" - Thomas Jefferson No more pain. 03.12.60 -- 12.28.10 http://www.youtube.com/Eightbanger |
|
|
|
|
03-27-2012, 02:46 PM
|
#6 |
|
Registered User
 Join Date: Oct 2005
Location: Overland Park, Ks.
Posts: 5,190
|
Re: Tranny leak help
There is a small seal in the adapter that holds the speedo gear. It is prone to leak.
|
|
|
|
|
03-27-2012, 09:20 PM
|
#7 |
|
Registered User
Join Date: Nov 2011
Location: Idaho
Posts: 857
|
Re: Tranny leak help
Check the gear for a groove where the seal rides
Posted via Mobile Device |
|
|
|
|
03-27-2012, 09:40 PM
|
#8 |
|
Registered User
Join Date: Nov 2010
Location: Carlsbad, CA
Posts: 1,584
|
Re: Tranny leak help
Here are pics I took when I did my speedo seal that might help you.
http://67-72chevytrucks.com/vboard/s...6&postcount=14 http://67-72chevytrucks.com/vboard/s...8&postcount=15
__________________
- Jim - My Daily Driver is a 1969 Chevrolet Custom/20 Fleetside 350/TH400/Eaton H052 4.10 and its Project thread is here http://67-72chevytrucks.com/vboard/s...d.php?t=456911 |
|
|
|
|
03-28-2012, 02:25 AM
|
#9 |
|
Registered User
Join Date: Nov 2010
Location: Fairbanks Alaska
Posts: 126
|
Re: Tranny leak help
When my trans was leaking from the speedo cable, I decided to make sure it was snug before I bought the gasket. Turned out it just needed a little bit of a turn to snug it up and it stopped leaking and I didn't have to bother with a gasket change.
__________________
You're not old, it IS loud! 1970 CST-10 BB 400 
|
|
|
|
 |
| Bookmarks |
|
|
Linear Mode
