[92OCC]

I want to replace my original rear end (drums w/out LSD). Is there a “bolt on” replacement as I don’t have a welder or cutting torch, with LSD and discs?

 

[Fix Until Broke]

There wasn't a wagon with rear discs from the factory to swap in. If your rear end is otherwise fine, here's a good rear disc option

Wagon Rear Disc Conversion (WRDC)

This is being posted to replace the previous thread (WRDBC) - probably missing some data that was on the original thread, will try to rebuild and keep current, if or until original thread is restored. Wagon Rear Disc Conversion (WRDC) Requires 17" wheels minimum Minimal track width increase -...

www.impalassforum.com

Unless your rear end has self destructed, you're better off to add limited slip and whatever else it needs and then add the disc brake kit above.

There are other rear disc brake kits available, but this is the only one I've found that retains a parking/emergency brake function.

 

[sherlock9c1]

That rear disc conversion kit is very well engineered. I have it and am very happy with it.

For LSD - Jegs makes an Eaton clutch-style posi that's very affordable. You can also buy a Eaton or Yukon clutch-type posi if you want. Although people don't like the fact that they do wear, they are not difficult nor expensive to rebuild, and can be tuned to behave however you'd like. Personally I've run Eatons in my cars and I'm happy with them. The gear-style LSDs are fixed bias ratios and are what they are.

 

[92OCC]

That rear disc conversion kit is very well engineered. I have it and am very happy with it.

For LSD - Jegs makes an Eaton clutch-style posi that's very affordable. You can also buy a Eaton or Yukon clutch-type posi if you want. Although people don't like the fact that they do wear, they are not difficult nor expensive to rebuild, and can be tuned to behave however you'd like. Personally I've run Eatons in my cars and I'm happy with them. The gear-style LSDs are fixed bias ratios and are what they are.

Is there not a complete rear end from another B model that would bolt up?

 

[Fix Until Broke]

Is there not a complete rear end from another B model that would bolt up?

In short - no

Sedans were the only b-bodies that came with rear discs (Impala SS, and 9C1 Caprice's I think?). Sedan and commercial chassis (Limo, Hearse, etc) frames are ~3" narrower than a wagon frames and the rear ends are also ~3" different in width.

You can put a sedan rear end in a wagon if you use the super soft rubber OEM rear outer control arm bushings and pull them in ~1.5" per side, it'll "bolt in". You'll then need wheel spacers in the rear or different offset wheels to clear the body and frame. The parking/emergency brake cables are also different between drums and discs (if that's important to you).

If your existing rear end is in otherwise good shape - the WRDC kit and any of a number of posi options are your best bet from a time and $ perspective.

 

[sherlock9c1]

Personally, the only annoyance with rear drums is keeping them properly adjusted. Otherwise, replace the wheel cylinders and hardware as preventative maintenance and then spend your money on one of the several bigger front rotor kits.

Although I no longer live in the rust belt, when I did, it was far cheaper and easier to keep rear drum brakes working properly than rear discs.

 

[Z09B4U]

GM and others have a history of products with seized rear calipers. Rear drum brakes have not disappeared yet from what I see in parking lots.

Search "seized rear caliper" and "rear caliper bolt" on this forum to see what can happen with rear calipers.

Unless you need repeated hard hot stops every day the larger heavy duty drums on a wagon(and B4U) when in working condition are enough to keep the car straight while the fronts do most of the real stopping.

 

[92OCC]

GM and others have a history of products with seized rear calipers. Rear drum brakes have not disappeared yet from what I see in parking lots.

Search "seized rear caliper" and "rear caliper bolt" on this forum to see what can happen with rear calipers.

Unless you need repeated hard hot stops every day the larger heavy duty drums on a wagon(and B4U) when in working condition are enough to keep the car straight while the fronts do most of the real stopping.

Thanks everyone for the feedback. A rear disc brake just looks so much cooler than my big o drums. lol. Plus my father has a 56 Chevy wagon with a 9 inch and Wilwood red discs and I can’t let him one up me! lol

 

[95wagon]

Plus my father has a 56 Chevy wagon with a 9 inch and Wilwood red discs and I can’t let him one up me! lol

There ya go dad.

I would recommend Bills kit,, but I'm a little biased 😉

 

[Dandy]

Kore3 has front and rear kits. As noted, the current rear kits do not accommodate a parking break. They are developing one and are hoping for it to be available in the next 4-6 months, pending supply chain and other COVID hurdles to finalize the product (I am assuming being able to get their team together)

 

[Z09B4U]

Kore3 has front and rear kits. As noted, the current rear kits do not accommodate a parking break. They are developing one and are hoping for it to be available in the next 4-6 months, pending supply chain and other COVID hurdles to finalize the product (I am assuming being able to get their team together)

Please provide a link that states they are working on a wagon axle kit. The 91-96 wagons were not a high production product and the number still on the road verses those owners who want rear disk brakes seems like a very limited market to design and produce parts for.

 

[Dandy]

Please provide a link that states they are working on a wagon axle kit. The 91-96 wagons were not a high production product and the number still on the road verses those owners who want rear disk brakes seems like a very limited market to design and produce parts for.

Z09B4U - happy to pass along the information. As you will see, they already have a rear kit for our cars. The kit they are working on is a rear kit with function of the parking brake. If you don't want a parking brake you can order from them today. I did send a message to Navy Life last week to see if he is still producing his kits, since the parking brake function appears to work. I have not received a reply.

Below is an email that I received from Kore3
Dan,

Thank you for your interest in our products. The front is pretty straight forward, and either of the kits below could be a good option assuming good fitment with the wheels specified. Wheel fitment templates are available for download here, and while I’m fairly certain that the 325mm C6 front kit will fit without issue, the 340mm C6 Z51 kits could be a little tight.

GM TALL-SPINDLE, B/D-BODY, ø325mm C5/C6
GM TALL-SPINDLE, B/D-BODY, ø340mm C6 Z51

For the rear, we have matching kits but no parking brake solution at this time for that housing/application. If that’s an issue, let me know and we can discuss options in that regard, as we may have some stuff on the near horizon to address that shortcoming. I would lean towards the 330mm Z51 kit for the rear, regardless of which front kit you choose, as the wheels should clear it without issue and you have a much heavier rear weight bias with the wagon as compared to a sedan.

GM 10-BOLT, 1991-1996 B-BODY WAGON, ø305mm, C5/C6
GM 10-BOLT, 1991-1996 B-BODY WAGON, ø330mm, C6 Z51

For the factory combination valve, you should get the ProForged stealth bolt kit for that in order to increase the rear brake bias. I’ve attached the front installation instructions so that you can review the spindle modifications required, however please let us know if you have any questions.

I responded with a question and below is the email where they mention they are WORKING towards a rear kit WITH parking brake function.
You’ll get the biggest bang for the buck with the front brake upgrade, but upgrading the rears certainly helps take some of the burden that would otherwise fall on the front brakes. With that said, the parking brake kit we’re working on for the B-body wagon rear uses the Wilwood MC4 mechanical (or electric) spot calipers, so while they’ll function like they should, they probably won’t offer the same holding torque as the large drum brakes from the factory. Our goal is to have these kits available for sale in the next 3-4 months give or take, though nothing really seems to be going per schedule during the pandemic.

 

[Blue Wail]

There's also the option of using all GM parts from a 9C1 or Impala as Goldsswagon did many moons ago:

New Page 3

Nab

 

[95wagon]

To hash over what many already know.
The big deal with wagons is the stand off dimension is shorter than "normal" Chevs.
Stand off is the measurement from backing plate flange to axle flange.

Bill's kit is a direct bolt on for those who don't want , or can't modify parts to work.
Also, up's the rotor size over stock Impala

Using all Impala-9c1 part route, leaves one to resize the center bore, redrilling the mounting bolts.
Simple for some, difficult for others.
The rotor spacing,
Charlie Costello dealt with custom longer axles, Gold SS wagon used off the shelf spacers.
Depending on wheel -tire choice, it can get pretty cozy.
About 1/4 + 1/8 from rotor hat= 3/8"
The spacer route, the rotor loses the centering of the hub, asking the studs along to center it.
There are two camps on this.
Personally I believe registering the rotor on the axle is important.
Other more costly route is to lopp the axle ends off, convert to bolt in axles using the standard GM stand off dimension.
This opens up your options to tons of brake kits as you are now the same as your typical GM

 

[92OCC]

View attachment 197515

There ya go dad.

I would recommend Bills kit,, but I'm a little biased 😉

Dad’s ready for the pumpkin.

 

[95wagon]

That's a long axle spline

 

[Navy Lifer]

As the WRDC "guy" (with assistance and attribution to 95wagon at the beginning, so long ago), I want to make a few things clear.

1. As configured, with 12" or 13" C5/C6 rotors, it is essential to use 17" wheels, which is not how the original sedan rear disc system worked - since 9C1 was 15" and Impala SS spare was also 15".

2. Rotor mass is king, and is always going to favor the larger Corvette rotors (in both sizes) - thus our original effort was never about using the sedan rear rotors. When the added rear weight/bias of a wagon vs sedan is considered, the larger rotors are a no-brainer. The nice thing is the ability to maintain a functional park brake, since the shoe size is common between the B-body and Corvette, along with a number of other vehicles.

3. There are probably other ways that disc brakes could be implemented on the wagon--as Gerry has alluded, the standoff distance of the stock axle setup in the wagon makes packaging more challenging. Still it remains more desirable for a number of reasons to stay with the wagon axle, as far as durability (larger shaft journal & bearing)....no denying sedan housings live today in a number of wagons, and IF someone wanted to upgrade the rear discs in a wagon with sedan rear discs, that is possible with the same bolt-on kit using C5/C6 parts I've offered for nearly 20 years.

4. Rear suspension geometry changes (unfavorably) with a sedan axle installed in a wagon, as well as spring alignment between body and axle.

Issues today:

• - availability of serviceable sedan backing plates
• - cost vs value of vehicle - justification
• - used vs new parts - a number of things more difficult to find, or used only
• - special machining of replacement rotors, caliper brackets
• - re-think of the rear caliper options, given the availability of many Brembo fixed calipers - what must be remembered is the PBR floating caliper takes axle float (lateral movement) out of the equation. A fixed caliper, whether Brembo, Wilwood, or other, can be problematic IF axle float is NOT able to be minimized or eliminated (no C-clip axle design, as in photos here - Aftermarket Axle register smaller than rotor).
• - personal commitment to keep building brake kits - I'm not going to be able to do this forever (I'll be 70 next month), and priorities change.