CK5
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Rear brakes?

MagnuM4WD said:
Hi! What type of drums, have GM 14bsf 9.5" ring gear: 11", 11-5/32", or 13"?

Well, I'm pretty sure that the 13" only come on 14BFF's, but it's a tossup as to what the other axles come with ... I swear I had 11 5/32"s on a 12bolt.

Anyway, you know what the LMC catalog says:

11" brakes have 2" wide shoes
11 5/32" brakes have 2-3/4" shoes
13" brakes have 2-1/2" wide shoes

70mm is right about 2.75", so yeah, I'd say you have the 11 5/32"s.

-- A
 
dremu said:
Well, I'm pretty sure that the 13" only come on 14BFF's, but it's a tossup as to what the other axles come with ... I swear I had 11 5/32"s on a 12bolt.

Anyway, you know what the LMC catalog says:

11" brakes have 2" wide shoes
11 5/32" brakes have 2-3/4" shoes
13" brakes have 2-1/2" wide shoes

70mm is right about 2.75", so yeah, I'd say you have the 11 5/32"s.

-- A
That's the way, I believe to, but, onest, I'm not shore!
 
MagnuM4WD said:
That's the way, I believe to, but, onest, I'm not shore!

Well, the other possibility is the 11" brakes, which would be a 51mm (okay, 50.8mm) wide shoe. Presuming you can measure 51mm from 70mm, I would say it's safe to assume you have the 11 5/32"s.

-- A
 
MagnuM4WD said:
Where you measure the drum diameter; inside, or outside?

Inside. It might even be cast into the drum, though that's a nominal value -- the 13"s I just checked are "MAX DIA 13.09", for instance.

-- A
 
OK! After I find all this informations, I go under the truck and I make some measurements... and... :eek1: surprise!!! The inside diameter of the drum, is 330mm!!! That mean 13"!
I looking also, to the steering controls and I find different tie rods, LH - RH! :confused: The RH is short (aprox. 150mm) and the LH is long (aprox. 1350mm), connected with a short adjusting tube. In the LMC Catalog, they say, this steering control, is use, only on the trucks with 13" rear brakes and 4.10 end ratio!
Can be 13" brakes on GM 14bsf 9.5" ring? It is in this way, from factory (stock), or is a kind of special order?
 
I don't have my manual handy or I'd look it up for you.

Where did this truck originally come from? (I mean where was the original destination) Stateside there were no "special orders", only options that you could specify. The manual will show everything available that year. Of course, there were variations in vehicles made for other countries though, that we may not have had as possibilities.

Just went and checked cskauto.com (stateside parts store chain) and sure enough, 13" drums with 9.5" ring gear is listed. Even have a picture.

Not sure if this link will work or not:

http://www.partsamerica.com/ProductDetail.aspx?mfrcode=RAY&mfrpartnumber=8022DGS&parttype=222&ptset=A
 
Fwiw..

I had 13" x 2.5" brakes in my 74 k20's 14 bolt SF--it came from an '86 K20 with a 8600 GVW ..my 82 K20 has an identical one to it also!..

I think both were 4.10 ratio--I know the one in my 74 was for sure,I've yet to pull the cover on the 82--I fear I'll find a Gov-loc in there!..:eek1:

Mostly the 11" brakes were in light duty 1/2 and 3/4 tons under 7000lbs gvw..the 11-5/32" ones were found often in vans and 1/2 ton heavy duty trucks with 10 bolt axles mostly..:crazy:
 
The label in the glove box will show a code "G80".

It's a factory "automatic locker" with not too good of a reputation. When it works, and is used in mild applications, there is nothing made (so far) that compares to it.

But they tend to break (quite often comparatively) although the problems are typically in the 8.5" rearends, the gov-lock in my 9.5" was broken when I got it.
 
I did't open yet, so I don't know if is broken or not. But, I see an oil leak, from the rear end and the oil is red, like ATF!!! Can be ATF, in the axles?
 

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