Rear Disc Article from Hemmings

[Staypuff68]

I read this article today on Hemmings, and with all of the parts recycling GM used on our Vans I was wondering if it would apply to us.

https://www.hemmings.com/stories/art...ign=2021-01-21

[kookykrispy]

"dimensionally, the rear axle bolt flange on the third-generation Camaro is the same as most older 10- and 12-bolt GM rear axle housings, making them compatible with virtually any '64-up 10- or 12-bolt rear axle assembly."

So it will bolt up to our vans rear axle no problem. Our vans use the same rear axle bolt flange as the muscle cars of the same 60's era. You are going to need to address the parking brake issue and trial and error will be necessary to find compatible rear cables in order to make the parking brake work. Also, you will need a master cylinder and combo/proportioning valve for 4 wheel discs.

[tinlizard]

"dimensionally, the rear axle bolt flange on the third-generation Camaro is the same as most older 10- and 12-bolt GM rear axle housings, making them compatible with virtually any '64-up 10- or 12-bolt rear axle assembly."

So it will bolt up to our vans rear axle no problem.

Probably so on a G10, but the G20 uses a 12T (for truck) differential, so the bolt flange may be different.
And those 5-hole rotors definitely won't work on the G20 6-bolt wheel stud pattern.

Bummer; I'd love to have them on my 4X4 which already has discs up front.

[108VanGuy]

I'm not convinced that rear disc brakes are a great idea for our vans. With a C-clip rear axle, the end play can only be reduced so much with shims. The remaining side to side play would tend to push the rear brake pads away from the rotor. This would be more the case after going around a turn where the axles would tend to push the pads further away from the rotor. The result would likely be a low brake pedal on the first apply since the caliper pistons would have to move further before they pushed the pad to the rotor. After the first pump on the brake pedal, I imagine it would be a higher pedal. Also, with so little weight in the back of our vans, I don't know how much we need the extra stopping power that would come with rear disc. JM2C
108VanGuy...

[tinlizard]

Excellent point, 108. I guess we'll all have to go to Dana 60 full floaters!

Wait a minute. I just remembered that years ago I had Dutchman Motorsports build me a rear Ford 9" full floater with Dana 44 front hubs.
Still lurking under the parts shelving in my shop. Why have I never installed it?
tb

[m1dadio]

I have been running rear disc on my daily driver 65 G10 for 14 years. I am not a big fan of it. I find it provides no improved braking. The 9.5 X 2 rear drums are plenty of rear brakes for a 1st or 2nd gen van.
Because of the "C" clip rear end I find the rear discs cause a lower pedal feel that the drum brakes do, the park brake built into the caliper is a maintenance headache needing constant adjustment (because they dont auto adjust like they are supposed to) You can get real cheep made in China calipers that are crap or pay large for made in America caliper like I did. ($200 each) By the time I finished installing the rear disc brakes including the modified re-engineered park brake system I was into it for almost $1000 and the only advantage I really gained see is at car shows I can brag about having four wheel disc brakes. That cost includes rebuilding the rear ens because you have to have less than .050" axle end play and most worn rear ends have about .080 or more.

that is my experience only.

however if you have a "Captured axle bearing" rear end or you want to by a captured bearing conversion kit to upgrade a C clip rear end you may have better results with rear discs. But I dont think those cheep rear disc kits provide room to combine a captured bearing conversion because the rotor wont fit the new axle and bearing assembly.

M1D

[lvjjj]

Except for some bad hoses from wheel cylinders to brake lines, I've never had any problems with my drum brakes and I think they stop just fine, been stopping okay for the 51 years I've been driving it. Just don't see the need for disc brakes.