I'm planning on doing a large upgrade to the rear brakes pretty soon since they need redone anyhow. I'm going to go larger than 1LE and plan to create my own backing plate. I'm going to attempt it provided it can be done within reason so I ask no one question the idea just the method. Just to throw stuff up I plan on using an original rear drum axle (yes, there are plenty of other easy way outs, but no fun in those) because the flange on the axle housing is larger than those on disc cars (that attach to the backing plate) I just need some info that I can't currently obtain and would appreciate the help.

*********|(caliper)
*********|
*******-x-
*******|
*******|
*******|
*--------|
*axle***|
*--------|

Ok, that's my best text-rendered drawing of a rear disc backing plate. Can anyone give me a general estimate about the distance X. Also, how does the backing plate mount to the flange on the axle housing? I'm assuming atleast the famous GM spot weld? Also, some parts will require welding and I planned on using a MIG. Am I ok to assume a MIG (fluxcore or gas?) welder will be safe for this application because I do not have access to a TIG welder. The other question is if anyone can anticipate how 'messy' parking brake cable routing would be if I didn't 'mismatch' the rear brakes like they are stock (toward the rear on the D side and toward front on F side). Thanks again.

------------------
1984 WS6 Trans Am Hartop
Former L69 Car under restoration
1984 WS6 Trans Am T-tops
4-bolt main 350, headers, Holley 650, T-5, dual elec. fans and 3.23's.
Daily driver and restoration
13.98 @ 101



[This message has been edited by 84FTA (edited January 18, 2001).]

 

Hey dude! You finally got it to the track!

Most caliper brackets BOLT to the backing plate. I'd have the tubes fully welded to the center section (you have to use a TIG for that [cast iron]) and fully weld the flanges on the axles (you should be able to get away with MIG on that).

About the bolt pattern (X) you'll need to get a set of rotors and calipers for that, every one will be slightly different, you'll need to mock it up and make templates out of card board or something.


If you want a Wilwood kit, My buddy is selling one DIRT cheap (easier than making the brackets)...

Drop me a line sometime, don't be such a stranger!

Talk to ya later man,

John (88 Camaro Goodwrench350 in FL) J812MANY@aol.com

 

If I were you I'd also get a set of 12 bolt flanges (pretty cheap) and a set of C-clip eliminators, and have the 12 bolt flanges welded on (you need a jig) and the elimators pressed on the axles, that kills 2 birds with one stone, A- you won't have to worry about losing an axle, and B- there are allready tons of brackets for 12 bolts w/discs.

 

I updated the picture hopefully now it shows correctly.

How does the stock backing plate connect to the flange. Bolts? I assuming you stated it and I'm just confused.

I'll have to access various metals to create the backing plates so I do not have to use cast iron I could use steel

This is more or less an expierement for better things and this is basically just an expierement for the time being. C-clip elimintors, cradle, ect will come around later

X wasn't meant to look like a bolt pattern. That's was supposed to be a rear view of the axle Hopefully it has cleared up. I have a pretty good picture of a backing plate now and it seems to be around 1" - 1.5" anyone support that? Thanks.


------------------
1984 WS6 Trans Am Hartop
Former L69 Car under restoration
1984 WS6 Trans Am T-tops
4-bolt main 350, headers, Holley 650, T-5, dual elec. fans and 3.23's.
Daily driver and restoration
13.98 @ 101

 

Your idea is intriguing. I have no doubt that someone with the right skills could carry this out. It has to be done right.

Speedway sells kits for other GM axles but not third gens. Most use stock GM or Ford hardware. Some have provisions for E brakes, some don't.

It seems that with all those third gens out there with drum brakes, some enterprising person could make a third gen kit that would sell like hot cakes. How about it Steve Spohn? I have a complete set of C3 vette brakes laying around. They sure would work nice on my Z28.

------------------
Nor Cal Mike
Red 84 Z28 HO, stock L82 350, L69 carb, intake, and air cleaner.
5 Spd, 3:73 Posi, 1 5/8" SLP headers, 3"cat connected to
stock L69 exhaust, KYB's, homemade SFC's,STB and wonderbar
Some are faster but mine's fast enough.

[This message has been edited by Nor Cal Mike (edited January 19, 2001).]

 

You can get caliper brackets from stock car companies such as Speedway, Coleman Machine and Winters (to name a few) that you can weld to the 3" axle tubes. As mentioned, get the rotors and calipers in position them fabricate the brackets. I would use 3/8" plate. At the offset ( "x" ) either gusset it well or use a section of round tubing. The E-brake cables will depend on what you use for calipers. If you mount them on the front of the rotors, you could probably use 2 right side cables or vice-versa.

 

Ah! Merf23! (even though John may of pushed on it early but I didn't register). The round tube is the exact idea I needed. Much better than my original plan to make the plate fully straight and weld on sections of pipe for a spacer. I may write a tech article on it but I doubt it'll ever see mass production.

------------------
1984 WS6 Trans Am Hartop
Former L69 Car under restoration
1984 WS6 Trans Am T-tops
4-bolt main 350, headers, Holley 650, T-5, dual elec. fans and 3.23's.
Daily driver and restoration
13.98 @ 101