What is this????

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.

SeanV

Member
Joined
Jan 15, 2021
Posts
42
Reaction score
17
Location
Dunedin
First Name
Sean
Truck Year
1977
Truck Model
C20 Suburban
Engine Size
454
Hey guys, need a little more help identifying what I’ve got. The truck is a 77 C20 Suburban that appears to have some of the stock suspension components taken off. The previous owner lowered the truck bu way of spindles and converted to 6 lug rotors. The rear end is a truck 12 bolt, but I’m trying to identify what it actually is. It’s got a very long vent hose on it making me think it’s from a 4WD truck. It’s got this circular ear on the passenger side of the housing. Any idea what this is from?
You must be registered for see images attach
 

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,948
Reaction score
25,339
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
Thats either an older truck rear... (60s) or car rear from like a monte carlo, malibu
 

SeanV

Member
Joined
Jan 15, 2021
Posts
42
Reaction score
17
Location
Dunedin
First Name
Sean
Truck Year
1977
Truck Model
C20 Suburban
Engine Size
454
It also has casting K13 8 on the driver’s side rear of the housing. You can see 123456789 under that weird eyelet. And GM 51 on the passenger side of the pinion section.
 

SeanV

Member
Joined
Jan 15, 2021
Posts
42
Reaction score
17
Location
Dunedin
First Name
Sean
Truck Year
1977
Truck Model
C20 Suburban
Engine Size
454
Thats either an older truck rear... (60s) or car rear from like a monte carlo, malibu
Even with just the one eye? Could that be where the panhard bar would’ve gone? I have more pictures if needed.
 

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,948
Reaction score
25,339
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
Even with just the one eye? Could that be where the panhard bar would’ve gone? I have more pictures if needed.
Im not 100% sure. @bucket may know closer then me. Theres other rear smart guys here to comment that i bet havent seen it yet.
 

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,948
Reaction score
25,339
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
Post a pic of the other side where the eye would be?
 

SeanV

Member
Joined
Jan 15, 2021
Posts
42
Reaction score
17
Location
Dunedin
First Name
Sean
Truck Year
1977
Truck Model
C20 Suburban
Engine Size
454
This is about the best one I have. Also one from the front look aft at the eyelet.
You must be registered for see images attach
You must be registered for see images attach
 

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,948
Reaction score
25,339
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
This is about the best one I have. Also one from the front look aft at the eyelet.
You must be registered for see images attach
You must be registered for see images attach
Im sorry i shoulda specified... the opposite side of the rear... (left to right). So from the back im interested to see the left side of the rear where that ear would be. Id like to see if somebody custom cut it.
 

SeanV

Member
Joined
Jan 15, 2021
Posts
42
Reaction score
17
Location
Dunedin
First Name
Sean
Truck Year
1977
Truck Model
C20 Suburban
Engine Size
454
Yes sir, that bottom picture is of the opposite side (drivers looking forward). It doesn’t have anything of the sort like that eyelet on the passenger side of housing.

Do you need a better picture?
 
Last edited:

RecklessWOT

Full Access Member
Joined
Feb 20, 2015
Posts
2,556
Reaction score
4,764
Location
New Hampshire
First Name
Kevin
Truck Year
1987
Truck Model
V10 Suburban Silverado
Engine Size
350 TBI
Do you have a picture of the whole rear cover? The cars and trucks were very different shapes. And from my understanding the car axles were actually better than the truck axles.
It's weird that one eyelet and being straight like that, usually there was one on each side and they were angled towards the front of the car. I'm sure there are dudes here who know a lot more than me
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
30,446
Reaction score
28,348
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
I'm not real familiar with them, but that big eyelet should make it a pre-'73 truck rear, specifically for a coil spring setup.
 

45acp

Member
Joined
Mar 5, 2021
Posts
45
Reaction score
24
Location
Antelope
First Name
Mark
Truck Year
1984
Truck Model
K1500
Engine Size
350
A Chevrolet parts dept. can ID that. On the RH (Passenger side) tube about 5 inches from the housing on top there is a 3 lettered code stamped on the tube. Sometimes it can be a real bear to find, a person hand stamped it. They will be able to tell you the year and what it came out of and what the gear ratio was from the factory. As I said it can be a bear to see but it's their. Brake clean/wire brush and a mirror are your friends.
 

eskimomann209

Full Access Member
Joined
Jan 9, 2019
Posts
1,849
Reaction score
2,005
Location
Modesto
First Name
Marcus
Truck Year
1973
Truck Model
C10
Engine Size
5.3
Looks like the 12 bolt on the 69 I just cleaned up. Guess is it probably was from the coil sprung rear. Someone probably welded some leaf perches on cuz that’s what they had laying around.

You must be registered for see images attach
 

SeanV

Member
Joined
Jan 15, 2021
Posts
42
Reaction score
17
Location
Dunedin
First Name
Sean
Truck Year
1977
Truck Model
C20 Suburban
Engine Size
454
I'm not real familiar with them, but that big eyelet should make it a pre-'73 truck rear, specifically for a coil spring setup.
That’s what I thought too. But it’s installed on leaf spring rear suspension. And, if this helps, it has 5 main springs in the pack plus the overload spring for 6 total. They’re 2.5” wide and 2.2” thick. Isn’t that a 4x4 1/2 ton set up? It’s clearly not the factory unit, but I’ll get a better picture of the pumpkin today. It looks to be a generic GM 12T truck housing save for that goofy eyelet thing.
 
Last edited:

eskimomann209

Full Access Member
Joined
Jan 9, 2019
Posts
1,849
Reaction score
2,005
Location
Modesto
First Name
Marcus
Truck Year
1973
Truck Model
C10
Engine Size
5.3
Well the 1/2t 2wd axles were 6 lug until like 70 or 71.
The spring perch distance remains the same for 4x and 2wd and the lead count goes more toward 1/2 ,3/4 or 1ton.
I think the WMS changes between the 2wd and the 4x. But I’m not 100% sure on this one.
Maybe measure it. And I’ll compare it to this axle which is a known factory 2wd 1/2t
 

Forum statistics

Threads
44,168
Posts
950,793
Members
36,284
Latest member
RogerioHR
Top