[95%]

Which b-bodies have G80's and also have disc brakes? Or how difficult is it to convert a rear to disc brakes? I really would like a posi rear!

thanks for any help in advance!!!!!!

 

[HuSSker]

Only 9C1's and Impalas had the G80 and disc brakes.

From:
http://www.impalassforum.com/vBulletin/showthread.php?t=227232


B-body rear DISC brake conversion
(fits 1991-96 B-body sedans with drum brakes, 8.5” rear axle)

Parts required to replace existing parts in rear drum brake system with OE discs from 94-96 Impala SS/Caprice 9C1:

1. Calipers & pads (1 of each item)
Caliper, OE LH & RH
Pad kit, OE FMSI D628 (1)

2. Caliper bracket, OE (2)
For RPO JL9, from 9C1 (or) WX3 (black)

3. Caliper guide pin, boot & caliper pin bolt, OE (4 of each item)

4. Backing plate (caliper mount & park brake), OE (2)

5. Park brake kit, OE (1 per car—part of item 4 with new plates)

NOTE: Items 1 thru 3 and items 4 & 5 are pre-assembled units

6. Fastener & washer for caliper bracket attachment, OE (4 of each item)

7. Park brake cable guide, OE—for right side only (1)

8. Bolt for cable guide / brake hose bracket retention, OE (2)

9. Brake hose—attaches to caliper, OE (2--1 of each item, L/R)

10. Park brake cable, OE (2--1 of each item, L/R)

11. Differential cover gasket, OE—revised design (1)

12. Strap to secure parking brake cable to axle tube (2)

13. Brake lines—for rear disc conversion, in stainless material (direct ship from Classic Tube)

Items not supplied with kit

14. Rotor (2) uses rotors for 94-96 Impala SS or Caprice 9C1
19195722 Rear rotor GM Durastop 18A656 OR EQUIVALENT

15. Differential lube/additive

16. Brake fluid

 

[95%]

so i can use all my parts off my 95' 9c1 and use them on the rear with the drum brakes? is this way even worth it or would it be more beneficial to convert my non-posi rear to posi?

 

[Navy Lifer]

The only rear axle that was 100% fitted with G80 and discs was the Impala SS - 3.08 ratio, all standard equipment.

The 9C1's were only equipped with G80 if that option was selected.

If the brakes on your 9C1 are working satisfactorily, it's my take that installing a posi/limited slip differential in that housing would be the better route.

Here's my reasoning:

The "guts" of your 95 axle are 15 years old--unless you are aware of repairs or maintenance that has been performed on the axle, it would be worth considering a complete overhaul--new bearings to go along with the new diff, perhaps a gear ratio change (gears wear too), and you can take a good look at the axle shafts to make sure they're ready for continued service.

Whether or not the donor drum brake axle you would be converting to disc brakes had been freshened already, you would still be looking at partial disassembly to change the backing plates.

On top of that, there's a fairly high potential for the G80 unit (Auburn) in a 15 year old donor axle to be worn and out of specs--and you would end up replacing it anyway, since Auburn LSD diffs are not repairable.

 

[95%]

thanks to both of u guys thats exactly the info i was looking for!!!!

 

[GennaroB]

Only 9C1's and Impalas had the G80 and disc brakes.

From:
Brake Parts List / Technical & Maintenance...


B-body rear DISC brake conversion
(fits 1991-96 B-body sedans with drum brakes, 8.5” rear axle)

Parts required to replace existing parts in rear drum brake system with OE discs from 94-96 Impala SS/Caprice 9C1:

1. Calipers & pads (1 of each item)
Caliper, OE LH & RH
Pad kit, OE FMSI D628 (1)

2. Caliper bracket, OE (2)
For RPO JL9, from 9C1 (or) WX3 (black)

3. Caliper guide pin, boot & caliper pin bolt, OE (4 of each item)

4. Backing plate (caliper mount & park brake), OE (2)

5. Park brake kit, OE (1 per car—part of item 4 with new plates)

NOTE: Items 1 thru 3 and items 4 & 5 are pre-assembled units

6. Fastener & washer for caliper bracket attachment, OE (4 of each item)

7. Park brake cable guide, OE—for right side only (1)

8. Bolt for cable guide / brake hose bracket retention, OE (2)

9. Brake hose—attaches to caliper, OE (2--1 of each item, L/R)

10. Park brake cable, OE (2--1 of each item, L/R)

11. Differential cover gasket, OE—revised design (1)

12. Strap to secure parking brake cable to axle tube (2)

13. Brake lines—for rear disc conversion, in stainless material (direct ship from Classic Tube)

Items not supplied with kit

14. Rotor (2) uses rotors for 94-96 Impala SS or Caprice 9C1
19195722 Rear rotor GM Durastop 18A656 OR EQUIVALENT

15. Differential lube/additive

16. Brake fluid

Tell me where I can buy the kit please.

Gennaro

 

[Navy Lifer]

The "kit" was based on component availability from 10 or more years ago - the aftermarket can supply nearly everything needed today. This is for sedan rear axle housings only.

The essential parts that are not sold in the aftermarket for an OEM disc brake conversion are the backing plates, brake lever boots & retainers, and park brake cable guide. A donor disc brake axle could provide these, or contact me for what I can provide.

The remainder of the parts can be purchased separately from many places - check Rock Auto for some idea of the varied source brands.

Rotors - multiple sources/brands
Caliper abutment brackets - Cardone - could be part of a "loaded" caliper/abutment
Calipers (with H clip) - remanufactured, multiple sources
Park brake cables - multiple sources (equalizer must be found or created)
Brake pads - multiple sources (D628 spec) - could be part of a "loaded" caliper/abutment
Park brake shoes - multiple sources
Slide pins, boots & bolts - multiple sources
Rear axle hard lines - Classic Tube
Hard line to caliper hoses - multiple sources
Fasteners, caliper banjo bolts - multiple sources
Miscellaneous items - some could be from a donor rear disc axle

 

[Caddylack]

Oh man... At first I thought that Bill bumped a 10 year old thread. 😂

 

[Caddylack]

Tell me where I can buy the kit please.

Gennaro

Just to be clear, there is no kit. That is just a list of parts that you need to find.

 

[Navy Lifer]

Just to be clear, there is no kit. That is just a list of parts that you need to find.

Well....some years ago I actually created a disc conversion kit with new or nearly all-new OEM parts - sold a few, but over time it was clear that people would prefer to buy a complete rear axle with discs already installed. It's hard to compete with that, except that those rear axles with discs mostly had unknown history, coming from salvage/dismantle yards, and half the stuff mentioned my require some sort of repair or replacement to make the brakes fully functional again.

I'm not offering to build kits (not that I can't) - but it would be much more worthwhile to do the upgrade kit (with C5/C6 rotors & calipers), typically for cars that already have discs - my normal deal was that the backing plates are returned to me, since they get modified for the upgrade. Difference is to go larger than Impala SS rear discs requires wheels larger than the 15" standard spare or OEM 15" alloy wheels (Caprice & RM sedan).