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 > General Truck Forums > All 4x4 Tech & Off Roading

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 05-25-2013, 04:01 PM   #1
robs71k5
K5drive
 
robs71k5's Avatar
 
Join Date: Nov 2004
Location: burnaby BC Canada
Posts: 809
"T"case leak

Np205 question
I have a leak in my transfer case but I"m wondering If I blew up a transmission and had it repaired but the seal between the transmission and "t"case was still a foul or the "t"case oil was never changed might explain the red colored oil coming from the "t"case. It seams the transmission oil level is consistent and doesn't seam to drop at all .
My question is there a way to drain the oil in the case to examine the oil. Then simply replace the seal in the "t"case to transmission adapter if required .I was thinking the "t"case leaked and over filled the "t"case and has been looking for a path out since the first transmission repair job and or are the seals ruined now because of the transmission oil contamination .Regards Rob
Posted via Mobile Device
Posted via Mobile Device
robs71k5 is offline   Reply With Quote
Old 05-25-2013, 05:03 PM   #2
Thealien
Senior Member
 
Thealien's Avatar
 
Join Date: Jun 2007
Location: Pine Ridge Florida
Posts: 4,126
Re: "T"case leak

On an NP205/TH350 set up (didn't say what you have) the adapter has 2 seals and an Oring on the input shaft of the transfer case. All 3 need to be in good shape or the transmission can leak into the transfer case. Here is a pic of the Oring on the input shaft. The coupler slides over it sealing the inside of the coupler. The two lip seals that go in the adapter seal the outside of the coupler.

You can see the lip seals in the adapter on the right

Attached Images
 
Thealien is offline   Reply With Quote
Old 05-25-2013, 07:21 PM   #3
robs71k5
K5drive
 
robs71k5's Avatar
 
Join Date: Nov 2004
Location: burnaby BC Canada
Posts: 809
Re: "T"case leak

Actually I was hoping to be able to drain the tcase oil first to verify how much oil is in it because I can't verify that other leaks in other surrounding output shafts are root cause , just saying if I have to remove it again I don't want the same mistake repeated. Meaning I didn't realize the tcase was filling up with red fluid when the tranny burned out and the tranny was repaired but the tcase wasn't removed, inspected.or even discussed about possible effects from tranny burning out so it could be fine other than it has to much of the wrong oil it .Does this sound reasonable ?the t case was overhauled in the restoration of the truck so I don't know why it would leak again now except the tranny oil is much more thinner than the 90 weight and could easily penetrate those seals much more aggressively
Posted via Mobile Device
robs71k5 is offline   Reply With Quote
Old 05-25-2013, 08:02 PM   #4
obijuan
Registered User
 
Join Date: Jun 2012
Location: cibolo tx
Posts: 1,033
Re: "T"case leak

Drain and fill with atf. Same fluid for both. It will be ok just a little noisier if you can even tell.
Posted via Mobile Device
obijuan is offline   Reply With Quote
Old 05-26-2013, 11:42 AM   #5
Ol Blue K20
Proprietor of Dale's Corner
 
Ol Blue K20's Avatar
 
Join Date: Nov 2012
Location: Vacaville , CA
Posts: 15,830
Re: "T"case leak

I think you should drain it and refill with 80/90wt and drive for a few days see if it starts changing color and if the level goes up.
Posted via Mobile Device
__________________
"Some Days Chickens And Some Days Feathers"

Dale
XNGH ECV Sam Brannan 1004

R.I.P. 67ChevyRedneck
R.I.P. Grumpy Old Man
Ol Blue K20 is offline   Reply With Quote
Old 05-28-2013, 03:02 PM   #6
willett
Another Day, Another Dollar
 
willett's Avatar
 
Join Date: Nov 2008
Location: North Vancouver, BC
Posts: 1,316
Re: "T"case leak

why don't you pull the fill plug and stick your finger in?
__________________
-78 K20 Cheyenne 454 long box, 4" lift, 35" MT's, '84 cab, '80 box

"its hip to be square"
willett is offline   Reply With Quote
Old 07-22-2013, 09:43 AM   #7
tgh117
Crazy
 
tgh117's Avatar
 
Join Date: Apr 2005
Location: Emmaus, Pa
Posts: 203
Re: "T"case leak

I have a SM465 / 205 in mine, but the seal went back in the adapter block so when I would drive it, it would pump the fluid out of the trans, overfill the transfer case, and blow the fluid out the vent tube. It would only really do it in the summer time, but it took me a little while to actually figure out the problem.

Once I did, I just slid the transfer case out, replaced the seal, put it all back together, and its been fine every since.

Good luck.
__________________
77 SB Stepside in a bunch of pieces scattered around the garage.
tgh117 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

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 02:08 AM.


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