Rear output shaft leak

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

kenneth1669

Full Access Member
Joined
Oct 25, 2022
Posts
55
Reaction score
19
Location
oregon
First Name
Kenneth
Truck Year
1977
Truck Model
K10
Engine Size
400
I have a 77 k10 and it seems to be leaking from everywhere it is possible to leak from. One of the first things I am trying to fix is my transfer case leak. I have a np203 and it seems to be leaking from the rear output shaft area. I have been researching and watching videos but every thing I read has a different solution to my problem. There was one forum that said that there is no seal gasket thingy there and that the only reason it’s leaking is because the vent was plugged. Another forum said there is a bushing inside taht could be bad and I would have to tear apart my transfer case which I would rather not do. Another problem I am having is I can’t seem to figure out how to pull the driveshaft out of the transfer case.

I hope I described that alright and didn’t make that too confusing. Any help would be appreciated. Thank you
 

kenneth1669

Full Access Member
Joined
Oct 25, 2022
Posts
55
Reaction score
19
Location
oregon
First Name
Kenneth
Truck Year
1977
Truck Model
K10
Engine Size
400
You can’t really see the leak. It looks small but last week when I first found it I cleaned the puddle up and stuff and waited a day and there was a pretty good sized puddle. I hope those are good enough photos. If not I can take more
 

Attachments

  • image.jpg
    image.jpg
    136.2 KB · Views: 73
  • image.jpg
    image.jpg
    102 KB · Views: 86

kenneth1669

Full Access Member
Joined
Oct 25, 2022
Posts
55
Reaction score
19
Location
oregon
First Name
Kenneth
Truck Year
1977
Truck Model
K10
Engine Size
400
I don’t know if this matters at all but I forgot to add that I have already drained the transfer case. From the look of the oil I am not sure if it has ever been changed before. The previous owner really did a number to this truck
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
10,041
Reaction score
10,132
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
No big deal.
You'll have to remove the driveshaft from the rear differential first. That pinion is a slip fit and removes with the driveshaft towards the rear of the truck.

The new seal is just like the grease seal of a brake rotor. Out with a flathead , in with a hammer.

Good luck.

*Dexron 6 is the correct fluid.
 

idahovette

Full Access Member
Joined
Aug 7, 2016
Posts
7,240
Reaction score
15,794
Location
Weiser Idaho
First Name
Perry
Truck Year
1975-1979
Truck Model
K20-K10
Engine Size
350
If it's a 203 case,motor oil is the correct fluid. We used to put the same oil in the 203 transfer case as what we put in the engine. It also looks like that is a bolt on yoke?
 

kenneth1669

Full Access Member
Joined
Oct 25, 2022
Posts
55
Reaction score
19
Location
oregon
First Name
Kenneth
Truck Year
1977
Truck Model
K10
Engine Size
400
Yeah I did some more reasearch and it seems to be a bolt on yoke. When I was first trying to remove it I was hoping it would just slide out but it seems like I will have to un bolt crap
 

kenneth1669

Full Access Member
Joined
Oct 25, 2022
Posts
55
Reaction score
19
Location
oregon
First Name
Kenneth
Truck Year
1977
Truck Model
K10
Engine Size
400
Yep, you got it.
Hey when I am taking off the yoke do I have to mark it at all. When I was doing my dif I had to but idk if I have to for this
 

idahovette

Full Access Member
Joined
Aug 7, 2016
Posts
7,240
Reaction score
15,794
Location
Weiser Idaho
First Name
Perry
Truck Year
1975-1979
Truck Model
K20-K10
Engine Size
350
Don't think it will make much difference, but it wouldn't hurt to mark it. Don't remember if the splines are one way only?
 

kenneth1669

Full Access Member
Joined
Oct 25, 2022
Posts
55
Reaction score
19
Location
oregon
First Name
Kenneth
Truck Year
1977
Truck Model
K10
Engine Size
400
Don't think it will make much difference, but it wouldn't hurt to mark it. Don't remember if the splines are one way only?
I have no idea I think I read somewhere there is a key part on it so it only goes one way. I’ll try and find that again and see what it says
 

kenneth1669

Full Access Member
Joined
Oct 25, 2022
Posts
55
Reaction score
19
Location
oregon
First Name
Kenneth
Truck Year
1977
Truck Model
K10
Engine Size
400
Don't think it will make much difference, but it wouldn't hurt to mark it. Don't remember if the splines are one way only?
Yeah I found it in my little Manuel thingy. It doesn’t anything about marking it just to use there little tool to take it off which I don’t have and don’t feel like getting. Thanks for the help
 

Snoots

Full Access Member
Joined
Jan 23, 2013
Posts
8,709
Reaction score
17,994
Location
Georgia
First Name
Roger
Truck Year
1973
Truck Model
Jimmy Sierra
Engine Size
350 w/203
You can usually rent/borrow tools at autozone, advanceauto and o'reilly's. Place a deposit and get it all back when you return it.
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
10,041
Reaction score
10,132
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
Yeah I did some more reasearch and it seems to be a bolt on yoke. When I was first trying to remove it I was hoping it would just slide out but it seems like I will have to un bolt crap
Maybe... Did you try yankin on it real hard?

xc_hide_links_from_guests_guests_error_hide_media
 

Attachments

  • 278563-e3e6a322744e4a6aabd334ba98a5d481~2.jpg
    278563-e3e6a322744e4a6aabd334ba98a5d481~2.jpg
    46.2 KB · Views: 60

kenneth1669

Full Access Member
Joined
Oct 25, 2022
Posts
55
Reaction score
19
Location
oregon
First Name
Kenneth
Truck Year
1977
Truck Model
K10
Engine Size
400
Alright so I got the shaft off and stuff and now the bolt on the yoke is a problem. At first I didn’t have the right sized socket. So I went out and got it and now it’s too big and won’t fit. What do I do now. Do I need to buy or rent some special socket?
 

Forum statistics

Threads
44,081
Posts
949,006
Members
36,158
Latest member
nobodyawesome
Top