BLAZER BACKING PLATE 4X4 VS RWD

M

mobileaudio25

G-Body Guru
Jan 12, 2012
518
43
columbus, ohio
Im looking to do a rear disc swap on my malibu finally. I dont have any f bodys at my local bone yard but there are some blazers/s10's. I plan on buying a new kit for the rear (caliper, pads, rotors, caliper brackets) but i cannot find any 2wd blazers at my local yard they are all 4x4. Does anyone know if the rear 4x4 blazer backing plates are the same as the 2wd backing plates? since im buying everthing new all that i need is the backing plate that mounts to the rear end housing.
 
8

81cutlass

Royal Smart Person
Feb 16, 2009
1,843
113
Western MN
To not answer your question-

Just buy the backing plates new from rock auto for under $12 a pop.

To answer your question-

The axle to caliper brackets are different between 2wd and 4wd. Calipers are the same, rotors on a 4wd have like 1" wider of "hat" where the e brake drum sits. Otherwise its pretty similar.

4wd puts the calipers forward of the axle centerline, 2wd puts the calipers rear of axle centerline. The calipers on a G body forward of axle centerline will hit the frame.

A right 2wd backing plate will be very similar to a left 4wd backing plate, but the caliper is clocked a few degrees in a different direction between the two. (see photo below)

A 2wd backing plate can be used on a 4wd axle and vice versa, you just need a tin snips and a few mins, also you have to be OK with another 1 inch of rotor showing or something but since nobody is mud bogging their G body its nothing to worry about.

If you are a real tightwad you can buy an entire 7.5 disk brake 4wd setup, flip the brackets so the calipers go on the opposite side from the blazer, buy new rotors, and reuse everything else. You just loose E brake capability unless you build another bracket.

1549312494449.png
 
M

mobileaudio25

G-Body Guru
Jan 12, 2012
518
43
columbus, ohio
To not answer your question-

Just buy the backing plates new from rock auto for under $12 a pop.

To answer your question-

The axle to caliper brackets are different between 2wd and 4wd. Calipers are the same, rotors on a 4wd have like 1" wider of "hat" where the e brake drum sits. Otherwise its pretty similar.

4wd puts the calipers forward of the axle centerline, 2wd puts the calipers rear of axle centerline. The calipers on a G body forward of axle centerline will hit the frame.

A right 2wd backing plate will be very similar to a left 4wd backing plate, but the caliper is clocked a few degrees in a different direction between the two. (see photo below)

A 2wd backing plate can be used on a 4wd axle and vice versa, you just need a tin snips and a few mins, also you have to be OK with another 1 inch of rotor showing or something but since nobody is mud bogging their G body its nothing to worry about.

If you are a real tightwad you can buy an entire 7.5 disk brake 4wd setup, flip the brackets so the calipers go on the opposite side from the blazer, buy new rotors, and reuse everything else. You just loose E brake capability unless you build another bracket.

View attachment 105443
Correct me if I’m wrong but don’t the backing plates bolt to the rear end or is that the caliper to axel bracket? I thought that these were the backing plates. Or are backing plates the same thing as the dust shields at well.

My main reason for the swap is if I throw an axle I don’t want it to go flyying while I’m in between rear end swaps if I even swap it. I also want it for aesthetics.

You pull brakes, axles, cut wheel cylinder tab off, bolt the complete part that I posted the picture of, drop axle in and install the brake setup right? Sorry for the confusion if I saw a 2wd setup today I would understand
 

Attachments

8

81cutlass

Royal Smart Person
Feb 16, 2009
1,843
113
Western MN
Correct me if I’m wrong but don’t the backing plates bolt to the rear end or is that the caliper to axel bracket? I thought that these were the backing plates. Or are backing plates the same thing as the dust shields at well.

My main reason for the swap is if I throw an axle I don’t want it to go flyying while I’m in between rear end swaps if I even swap it. I also want it for aesthetics.

You pull brakes, axles, cut wheel cylinder tab off, bolt the complete part that I posted the picture of, drop axle in and install the brake setup right? Sorry for the confusion if I saw a 2wd setup today I would understand
Yeah, I the backing plate is the dust shield. The cast iron part is the caliper bracket.
 
  • Like
Reactions: mobileaudio25
M

mobileaudio25

G-Body Guru
Jan 12, 2012
518
43
columbus, ohio
So I can use everything from the 4x4 blazer (caliper bracket, dust shield, caliper, pads) and it will all work on my 8.5 I just need to get a rotors for a 2wd
 
8

81cutlass

Royal Smart Person
Feb 16, 2009
1,843
113
Western MN
Yeah, the only issue you run into like I mentioned is that to use all the 4wd stuff minus rotors you have to flip the sides the brake parts came off so you loose the e-brake cable bracket since it points backwards instead of forwards.

Some people that run coil overs have the spring hit the caliper, but if you run normal shocks that shouldnt be a problem.

Just an FYI, those dust shield/backing plates rust VERY fast from the factory and the 2 axles I have bought for parts had them entirely rusted out. It's a good opportunity to spend the $25-$40 to buy nice new shiny parts and get a pair of new ones.
 
M

mobileaudio25

G-Body Guru
Jan 12, 2012
518
43
columbus, ohio
Yeah, the only issue you run into like I mentioned is that to use all the 4wd stuff minus rotors you have to flip the sides the brake parts came off so you loose the e-brake cable bracket since it points backwards instead of forwards.

Some people that run coil overs have the spring hit the caliper, but if you run normal shocks that shouldnt be a problem.

Just an FYI, those dust shield/backing plates rust VERY fast from the factory and the 2 axles I have bought for parts had them entirely rusted out. It's a good opportunity to spend the $25-$40 to buy nice new shiny parts and get a pair of new ones.
That seems easy and i dont plan on using the ebrake at all my line is broken and shot its an auto 4l80e also. im not running coilovers just a normal umi sport shock. ive read they are pretty nasty i saw some on the 4wd setup.

i plan on buying a complete 2wd kit (slotted drilled rotors, calipers, caliper brackets, and pads)
since the 4x4 axel to caliper bracket will only relocate the position of the of the caliper and the caliper bracket and caliper are the same part number the complete 2wd blazer kit should bolt right up. cheap nice new red powder coated calipers from power stop.
 
M

mobileaudio25

G-Body Guru
Jan 12, 2012
518
43
columbus, ohio
Yeah, I the backing plate is the dust shield. The cast iron part is the caliper bracket.
I finally located a 2wd balzer, if this one is a no go then im not going to get it and i will go with the 4x4 setup. I noticed the different caliper orientation you were talking about on the 4x4 setup...

on the rear of the blazer that i found the caliper brackets that bolted to the rear end housing were still attached to the rear end but someone had taken one side apart and the dust shield was rusted out and gone. I found the brown circular shaped piece of metal that goes around the 4 bolts in the picture i attached laying on the ground. also that silver piece that is inbetween the legs on the brown circular piece is missing also. these are the emergency brake parts correct? if im missing the small silver piece in the bottom of the picture and the brown piece of metal that goes around the 4 bolts i should still be ok right? i know both of the metal pieces that bolt to the rear end hosing are there... I didnt get it fully disassembled because i couldnt rotate the rear end to drop the c clips so i didnt get to actually see everything all stripped and apart to get a good idea. thanks
 

Attachments


Please support GBodyForum Sponsors

Classic Truck ConsolesDixie Restoration DepotMike's MontesP-S-TSouthside Machine PerformanceUMI Performance

contact[email protected]for info on becoming a sponsor