# Rear Disc Conversion



## carbon02 (Feb 25, 2011)

I thought something like this has been discussed. It was either drum to disk, or solid axle to Z-Link.  If I recall something was different with the mounting of the hubs to the axle and the parking brake cables for the conversion. 

I remember someone mentioning that you had to take the entire axle and parking brake cables to make this work.

Possible sure now that parts are available salvage someone might try it. Back when I remember it being discussed the Cruze GEN 1 was a few years old, and parts were expensive. Now I see them ending up in U-Pull yards. If you could get the entire rear end with cables and bolts and hardware it may make sense. 

I vaguely recall them mentioning that some of the mounting hardware was actually different as well. So get all the bolts for this conversion as well.


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## plano-doug (Jul 1, 2015)

JS6167 said:


> Any foreseen problems with this like bolts? Parking brake, etc? If you have negative criticism about disc in general, skip over the post. Just looking for opinions and if any bolt alignment or previous knowledge any member has may help in my en-devours. The only real concern I see with this is the hydraulic line, parking brake cable and the hub mount bolts if they are in a different pattern?


I think you're on the right track with those questions. Besides answering those, other hardware to consider includes the proportioning valve, master cylinder, and the ABS and traction control units. Are they the same for both drum and disk? 

And that leads to the electronics. Do the wheel speed sensors from the disks emit the same signals as the drums? That is, will the computer stumble over the new gear? Will the electronics that drive the ABS and traction control units need swapping or re-programming for the disks?

If I'm a designer at GM, I'm going to try to make the various modules the same on both braking systems, but that may not have been possible thus requiring different gear. You could end up needing more than just hubs, rotors and calipers; you may need to get the underhood braking gear, too.

Unfortunately, I don't have the answers to those questions, but I would want to answer them before I start taking the rear end apart.

It may be tedious, but using one of the on-line vendor websites may be a good starting point. Enter a drum model - eg, Cruze LS - and look up the part numbers for the various pieces, then enter a model with rear disks and get those part numbers. Figure out which ones match and which ones don't, and you'll have a clearer picture of what's involved.

Perhaps someone else here can answer some of that, otherwise some digging will be required.

Doug

.


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## JS6167 (Apr 16, 2020)

I’ve been looking at parts and everything seems to be exactly the same including the hubs. The bolts will need to be longer but, the parts I think you’ll need is the backing plates, mounting bracket because of the calipers, calipers, caliper mounting bracket, pads, rotors and new brake lines just in the rear. Other than that I can’t find any different numbers


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## carbon02 (Feb 25, 2011)

The best GM parts drawings on the internet used to be the following: 






2012 Chevrolet Cruze LT2 4DR BRAKE CALIPER/REAR


Diagram of OEM BRAKE CALIPER/REAR. Contains 12 parts priced between $6.08 and $160.30. Fits 2012 Chevrolet Cruze LT2 4DR.



www.wholesalegmpartsonline.com





Lot's of detail there, you'd have to check the 2LT rear parts vs. the 1LT with drums..


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## JS6167 (Apr 16, 2020)

Thanks carbon! I have been looking at each individual part that could be "different" other than obvious and haven't found any differences in part numbers or design so far. I also found a parts dealer that has a 12' 2LT and he will pull all parts and ship them for $125. That includes rotors, pads, hubs (even though they're the same), calipers, caliper brackets, hub mounting bracket (for caliper to mount to), bolts, hoses, abs sensors and the dust sheilds. (Basically the entire both corner assemblies off the car other than the springs,shocks and axle. He mentioned that if the axles were different then I can get it as well. 

I'll keep the everyone updated if I receive the parts and how the install/ after install goes!


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## carbon02 (Feb 25, 2011)

Assuming you have a Z-Link axle, you may want to check the mounting location of the caliper bracket to the axle itself. The caliper bracket attaches to the axle vs. the hub bearing right? That could be a sticky point that may require you to get the entire axle. 

Don't forget the parking brake cables all the way up to the dash assembly from inside the car. Unless you've verified part numbers. The 2LT rear rotors use a really weird parking brake assembly actuator. And I think the caliper includes some sort of vibration dampener assembly as part of the caliper bolts. All Euro design stuff, used more on the Euro Cruze and I believe the Opel Astra J. 

I'm all for a unique project. I was one of the first to rip out the seats and install headed aftermarket seat pads under the factory cloth. I would have them pull the entire axle. Worst thing would be they crush the remains between the time you pick up the brake hardware and find out that you need more than what you have.

I would think the rear axle components would be cheap, as not many people fix this in an accident. However finding a 2LT or an LTZ and getting someone to pull/sell those components could be difficult. 

Good Luck.


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## Blasirl (Mar 31, 2015)

I was always under the impression that a Z Link always came with rear disks. I second buying the complete rear including all hardware,. If this a U Pull it or LKQ type yard, I would do it myself just to see how it comes apart. If not, I hope this guy is mot too lazy as it could cost you a pretty penny just for misc hardware. 

I also thought there were one or two brave souls who have done the drum to Z-Link swap, but I am not 100%

I am waiting to see what you come up with though as this has always been in the back of my mind.

Something else to consider: Bigger brakes for the Cruze under $400.

Additional info:

How to Adjust Rear Drum Brakes 
How to: Replace rear e-brake cables (inside the car) 
DIY How to replace Brake Vacuum Booster Pump and Pipe 
DIY Flush Brake Fluid 
AMSOIL Series 500 & Series 600 Brake Fluid


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## JS6167 (Apr 16, 2020)

Thanks Blasirl. I have a Brembo kit for front and rear to put on as well I really just needed all the hardware but I definitely agree with the whole rear. Gonna be easier to swap and I can undercoat and repaint the components while I’m there


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## JS6167 (Apr 16, 2020)

So correct me if I’m wrong, but my car definitely has the Z-link rear. Which means I should be able to order the bolts, adapting plates, calipers and brackets along with brake lines ( Ik there’s various other things) but with all that I would have rear disc brakes essentially. Ik there’s a lot of controversy this is just the way I’m going. All my research tells me that if I do indeed get these parts then I will have rear disc brakes so long as I have the Z-link axle? I’m an engineer btw and all the diagrams I have found are the same. They all point to the same rear and same wheel hubs


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## Blasirl (Mar 31, 2015)

JS6167 said:


> So correct me if I’m wrong, but my car definitely has the Z-link rear. Which means I should be able to order the bolts, adapting plates, calipers and brackets along with brake lines ( Ik there’s various other things) but with all that I would have rear disc brakes essentially. Ik there’s a lot of controversy this is just the way I’m going. All my research tells me that if I do indeed get these parts then I will have rear disc brakes so long as I have the Z-link axle? I’m an engineer btw and all the diagrams I have found are the same. They all point to the same rear and same wheel hubs


Well, you just disproved the Z-Link always has four wheel disk theory. I agree. You should be able to convert. Make sure you document and take pictures for us.

How-To: Write a Tutorial


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## JS6167 (Apr 16, 2020)

PROGRESS MADE! So, I found a full watt-link rear from a scrap yard complete with everything including shocks, calipers, brackets and other various parts for $150. Went to get it an all the hoses were shot... Figures. But I went ahead and pulled everything off my rear axle and almost had it off. When I got the axle home I realized they were the exact same thing. Unbolted and installed (after cleaning up parts) all of the rear parts except shocks and springs. They bolted right up and the change really was not hard atall. Hubs were good on the new one and i couldn't get the dust shield off my drum brake hubs so i used theirs. Installed with new grease, slide bolt boots, new rotors and pads and it is all back together other than the brake lines and the parking brake cables bc the local stealership had to order them. Overall with new cables and brakes I spent about $325 for everything and even if the cables were ok its a good idea to replace. So it is entirely possible and relatively easy and if you have the watts(Z) link rear all parts will bolt right on. Took about 3.5hrs to take pictures almost take the rear off (which again you dont need to) and install everything but the cables. Will be doing that later this week so I'll make a complete HOW-TO about it with pics, steps, tools and various tips. Very happy with the results


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## Aussie (Sep 16, 2012)

I find this interesting, especially when people argue that the drum brakes are as good as rear discs. In Australia when the 1.6T was released the bigger brakes off the diesel were standard along with the 5x115 stud pattern. It also came standard with sports sway bars F & R as well as a watts link (Z Link). The suspension was also a little lower and stiffer. Being the same price as the 1.4T after about 1 year the 1.4T was discontinued in 2013, leaving just the 1.8, 1.6T and diesel engines available. Every Cruze models sold in Australia came with all disc brakes.


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## JS6167 (Apr 16, 2020)

AUSSIE, I wish they all came with rear disc and we could get the 1.6T in the US. Oh well, apparently gm didn’t wanna give us the fun car stock


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## Aussie (Sep 16, 2012)

GM wants to join the all truck companies and is gambling on EV vehicles to bail them out in the next oil crisis. All foreign companies that sell in the US must be smiling from ear to ear at Ford and GM strategy.


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## JS6167 (Apr 16, 2020)

I know its been awhile, but I wanted to really test the car before I made any final conclusions. If you have that watts link rear, the only parts you need are calipers (with the springs and such), rotors, the caliper brackets for both sides, rear brake cable sections, and the parking brake cables. I had a bit of trouble ordering the parking brake cables but they are a GM part with a large ball on the end to retain it. The bolts, rear hubs, wheel speed sensors and axle are the exact same!! I have run it on the car for just over a year and it stops great. Went to a few autocrosses with it and parking brake works.


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## Thebigzeus (Dec 2, 2018)

Nice, if you don’t have the watts link, can this still be done?


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## Aussie (Sep 16, 2012)

Thebigzeus said:


> Nice, if you don’t have the watts link, can this still be done?


Most models in Australia don't have a watts link, but all have rear disc brakes, so there should be no problem.


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## JS6167 (Apr 16, 2020)

I mean essentially its just a sway bar. I believe it will all work as long as the rear hubs have the same bolt pattern. I would recommend looking for the parts on GM Parts Direct and find the correct cable part numbers for the lines and such. When I did mine, I bought a used rear axle with everything and the only thing I took off was the calipers and brackets as the lines were shot. Honestly it might be cheaper and more reliable to buy new. Dealer ordered the "right" parts 15 times before I gave them the right numbers. Really easy swap. Even the parking brake end that attaches to the cable is the same.


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## Thebigzeus (Dec 2, 2018)

Yeah, I was kinda looking for a list cause I don’t really have time to put in the legwork. Thx, I may look into it in the future.


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