What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Rear Axle in 1974 Blazer

Chief Brody

Chief Brody

"Amity Island Welcomes You"
 Premium
GMOTM Winner
Joined
May 18, 2010
Posts
9,606
Reaction score
1,980
Location
Alabama
I had a hard time finding the brake shoes for my Blazer...Every one I looked at in the box was 2 inch width but the computer shows 2 3/4" which is what the ones are that came off.

I ordered Raybestos from Rock Auto 280PG and it said they were 2 3/4 but when I opened the box 2".

Same thing when I went to O'Reilly and AutoZone and Advance.

I looked up a 1974 Jimmy and it had 3" brakes

I finally looked at a 1978 Blazer and it had the 2 3/4" brakes #473 at Oreilly.

What gives??? Do I have a 1978 axle on my 1974? Or is something else going on?
 
Hmmm. I opened this thread thinking that I would have an answer for you...


I was wrong.


Let's ask Martin. @82355


He tends to have lots of info on when things were produced and when they weren't.
 
Far as I can recall they had only 2 sizes of rear brakes on the 10 bolts--11x2"(which are the #280 shoes) and 11-5/32 x 2-3/4...(The #248 shoes)....the #473 shoes may have superceeded the #248's..

I went through this on my '81 van after I replaced the rear end with one from a salvage yard--close if not the same year,but my original had 11 x 2" brakes,the replacement one had the larger 11-5/52 x 2-3/4" brakes..
I also learned the rear axle bearings "might" be larger on rear ends with the larger brakes too,according to some parts catalogs (never had to replace them so I cant say for sure)..
 
mine is a 12 bolt...at least it has a 12 bolt cover
 
diesel4me said:
and 11-5/32 x 2-3/4...(The #248 shoes)....the #473 shoes may have superceeded the #248's..
I
Click to expand...

the problem is that when you buy "248"s and you look in the box, you get 2 inch wide shoes...I don't get that
 
I had two 12 bolt rears that had the same shoes,one on my '72 K5 had the 11 x 2's and the '79 C-10 Bonanza had the 11-5/32 x 2-3/4" ones..
I think some 3/4 tons also had the same size brakes,also 13" drums were available on higher GVW 3/4 tons..

I looked on Rockauto's listings to get those part numbers listed above--evidently someone has the wrong info in their computer or catalogs--or the shoes are boxed wrong..they ARE very close in measurements and look almost identical..

It is possibly your rear axle is not original too--one way to tell is to look for the 3 letter code on one of the axle tubes,its supposed to be stamped on the right side near the spring pad,but I have found them on other areas of the tubes on either side..--it'll be like "RAX" or similar,if you can find it then you can look the code up in a GM parts catalog to find the ratio and brake info,the production year..

My '85 Burb has a 12 bolt rear axle and looks to be 100% original too,despite GM supposedly not using them after 1980 or so..but I haven't tried de-coding it to see if it was the original ..
 
Have you tried napa, 248's are the ones (2 3/4) same as what u said came off.
 
blazer74 said:
Have you tried napa, 248's are the ones (2 3/4) same as what u said came off.
Click to expand...

NAPA was the one place i didn't go to because they are so far away...the local store closed
 
the "473" shoes worked...it just bugs me to have to lookup parts for a 1978...I think something is wrong with the parts system though...my 1973 dealer manual for ordering 1974 Blazer new definitely lists a 2 3/4 shoe
 
they don't even carry a brake spring in the parts stores anymore...they have to order them overnight...

carrying fewer and fewer parts for the squarebody, but odd that they still carry taillight lens...on an endcap...go figure
 
Yeah,there hasn't been much for my square bodies I could walk in a parts store,buy,and go home with the past several years--its always "we have to order that--we show one at the warehouse,we can get it later in the afternoon if you let us know before 10 am--or tomorrow--three days from now...it gets aggravating,you'd think they would stock things like brake calipers,master cylinders,brake hardware kits,and wheel cylinders,seeing they fit so many years,despite being "antique"...
I had a 3 day wait for the E-brake cables for my '82 GMC,and the intermediate one was about an inch or two too short--I was able to fudge it on there by not routing it through one frame cable guide "loop",but it irks me they cant make something that fits "right" without having to modify or jerry rig it..

I will have to order a gas tank if I want one now--used to be I could go 15 miles to the warehouse and buy one "direct",but now they'll only sell to parts stores or garages..at 20-30 bucks more than if I bought it direct..

I recall many brake shoe listings being "wrong" back in the 80's when I was a counterman,often we had to match up the original shoes..this was a big problem if the customer brought his "cores" in,and just took the new shoes and left his cores in the box (which was required to get core credit)--if he did not discover the new shoes were not correct before we sent off his cores to the warehouse,it was a fiasco trying to figure out which ones he really needed !..

I think many brake shoe cores do not get identified properly too--they just go by whats printed on the box--they didn't take into account the axle may have been swapped out for one off a newer or older vehicle..
Also many of the brake shoes were "superseded" and they consolidated many part numbers after they figured out many were interchangeable,or could be,by simply drilling another hole in the webs during the re-lining process..and GM has been known to use up old stock or start using parts listed for later models earlier than the catalogs show too..like those 12 bolts showing up in many 1/2 tons long after they were supposedly discontinued..
 
I still haven't found the stamping on the rear axle, but I bet it is original...everything else on this one has been...
On stocking parts, I don't expect them to take up space with a lot of parts for these old trucks, but just the most common things that make them go or break and strand you....the real big loss for me is the removal of the "HELP!" section from almost all parts stores...you used to be able to buy a spring assortment to get you by..etc..
 
The parts stores here still have the "HELP" rack,Pep Boys has the largest assortment ,practically all the things you'd have to go boneyard hunting for otherwise,but their prices are sky high--some other stores have scaled way back on their "Help" and Dorman racks though..

I tend to hang onto all my old "useable" parts when I replace things like brake hardware--having an old rusty spring is better than none,on a Sunday afternoon when all the "real" parts stores are closed..more than once I have had my butt saved by having a stockpile of "used junk" hanging around..

I also get a lot of "leftovers" from my friends shop,things he bought while repairing a customers truck--not long ago he had to buy a brake spring & hardware kit and only used one wheels worth--I took home the rest of the kit--not 2 weeks later I needed new brake shoe hold down pins,when I went to replace the e-brake cables and those slotted washers,and the ones I got from him were a perfect fit..

I also scoffed up the e-brake cable connector things off an old cable in his scrap pile,that saved me from hunting one down at a boneyard or parts stores..sometimes if he does a brake job on a truck like mine and the rotors or drums still look good,but the owner wants them replaced regardless,I end up with them..
 
Chief Brody said:
I ordered Raybestos from Rock Auto 280PG and it said they were 2 3/4 but when I opened the box 2".
Click to expand...
I had the same experience with my '74. We have the heavy duty brake package (I still have the options list sticker in the glovebox). In years past I don't recall ever having any discussion at the parts counter about my brake pads. This last time the lady at NAPA asked me which pads and I tell her the pads for a '74 K5 like I said. We go around a few times and I realize she knows what she is talking about and I don't. So I got both pads and she would take back whichever I did not use. I don't know the exact size of the pads but the smaller ones were the standard that she said I should need and the larger were the heavy duty that I did need.
 
Last edited:
The O'Reilly computer only listed one pad for the 74 K5. The Rock Auto site listed all of them including the heavy duty. The number I got for the 2 3/4 was the same number...280PG and it said they are 2 3/4 inch wide. In the box they are not.
NAPA only listed one shoe...Advance only listed one shoe...all 2"
Something is amiss in their computer system or at the manufacturing plant.

If you lookup a 74 Jimmy at the parts store, they show it to have a 3 inch shoe.

I ended up with O'Reilley part number 473...they are 2 3/4 and they fit...but they have no association with 1974 of any kind in their systems
 
I may have found the axle code, not sure...will post the images when I download them a little later
 
it looks like GA09 or something like that:

20161008_173025.jpg 20161008_173020.jpg
 
You must log in or register to reply here.

Latest Posts

Top Bottom