disc brake rear in my drum brake bird HELP!

[richduty455]

So the rear in my 94 bird went on me, and I'm in a scramble to get a rear for it......I'd like to get a 3.23 posi for it, but I'll prob only find one of those in a z-28 or T/A.....now my question is if i get a disc brake rear out of a t/a can i bolt my drum brake backing plates to the axle tubes and use it in my car?

[donnj]

why would you want to convert it back to a drum if you end up getting a disc rear?

[Jersey Mike]

If you want to make a 200-some-odd round trip, you can have a V6 drum rear out of a '95 for free.

[BonzoHansen]

Originally Posted by richduty455

.....now my question is if i get a disc brake rear out of a t/a can i bolt my drum brake backing plates to the axle tubes and use it in my car?

yes.

Originally Posted by donnj

why would you want to convert it back to a drum if you end up getting a disc rear?

I don’t know these cars, what is involved in going to rear disc brakes? Is the master different? Is there a prop valve or just an ABS units like the later ones? Will the ABS be confused if you change to discs? What line changes are needed in the back? I know how it works for older cars, but I’m not sure on 4th gens.

[WildBillyT]

Originally Posted by BonzoHansen

I don’t know these cars, what is involved in going to rear disc brakes? Is the master different? Is there a prop valve or just an ABS units like the later ones? Will the ABS be confused if you change to discs? What line changes are needed in the back? I know how it works for older cars, but I’m not sure on 4th gens.

I had posted the same thing as Don but then deleted it for that reason. I don't know what's involved. I think the prop block is the same but I'm not sure.

[richduty455]

i want to keep the drum brakes......even if i got a drun rear, i'd prob unbolt my backing plates that way I don't have to play with opening up the brake system.....so i should be able to bolt the drum backing plates to a disc rear?

[sweetbmxrider]

Yes, the 10 bolt flanges are the same. You unbolt the caliper mount and bolt up your drum brake setup. You'll probably have to at least pull the drum off to bolt it up to the axle tube. The disc rear will have hoses going to the calipers while your drum rear has hard metal lines going to the wheel cylinders. Start spraying penetrating oil if you don't want to do an overhaul on the system. Note the routing of the ebrake cables too.

[91zconvert]

Originally Posted by richduty455

So the rear in my 94 bird went on me, and I'm in a scramble to get a rear for it......I'd like to get a 3.23 posi for it, but I'll prob only find one of those in a z-28 or T/A.....now my question is if i get a disc brake rear out of a t/a can i bolt my drum brake backing plates to the axle tubes and use it in my car?

i've got a disc rear out of my 93 Z28, 6 speed.i want 200.00 for it

[richduty455]

is it a 3.23?

[sweetbmxrider]

Oh and I completely forgot to mention you have to pull the axles out....derp.

[MyFirstZ]

Originally Posted by sweetbmxrider

Oh and I completely forgot to mention you have to pull the axles out....derp.

Was going to update your write up with this......but you caught it

[V]

were all drum rears 3channel? if so a 4 ch disc rear would be useless because it won't have the provision for the abs sensor that goes into the top of the housing.

[richduty455]

if it helps car is a 94 v6, rear drum no traction control.

[V]

id suggest just getting another drum rear and doing a quick swap.

[Featherburner]

Originally Posted by 91zconvert

i've got a disc rear out of my 93 Z28, 6 speed.i want 200.00 for it

Originally Posted by richduty455

is it a 3.23?

It's either 2.73 or 3.23. That's what came with the 6 speed in 93.

[sweetbmxrider]

Originally Posted by V

were all drum rears 3channel? if so a 4 ch disc rear would be useless because it won't have the provision for the abs sensor that goes into the top of the housing.

Yeah, good point. It would be a 3 channel rear. Not having abs makes me not think/care about it

[Dudbird113]

Make sure u get wat gear ratio ur car has or ur speedo will be off and need a tune. Pretty sure the masters are the same for drum and disc abyways. If not just get a 40 dollar prop valve or i wouldnt even worry

[richduty455]

Yea thats why I want to get 3.23's.....car had them originally and p.o changed it to 3.42 non posi and didn't fix the speedo....so as i drive the car i have to do math...keeps my mind sharp atleast....hahaha

[Blacdout96]

If you convert to disc, you will need to change out to a LT1 prop/ABS unit since drums don't require as much pressure as disc do to operate properly, spo the calipers may not function correctly. Also, drums need residual pressure to prevent the pistons in the wheels cylinders to retract fully. This may prevent the pistons in the calipers to retract fully, making them push up against the rotors.

3.23's are the only rears the 3.4 F-bodies came with ( Manual & Auto) in 96+ the ratios were either 3.08 (Auto), 3.23 (Manual) or 3.42 posi ( Y87 performance package)

If you are to go rear disc, may I recommend LS1 setup. I find it more reliable, and with the hat system, replacing pads is a sinch. You will need to change your front parking brake cable to a 96+ because it is slightly longer to accept the LS1 cable lines.

Oh, and I have both LS1 and LT1 full sets for sale if interested

[91zconvert]

Originally Posted by richduty455

Yea thats why I want to get 3.23's.....car had them originally and p.o changed it to 3.42 non posi and didn't fix the speedo....so as i drive the car i have to do math...keeps my mind sharp atleast....hahaha

well mine came out of a 93 6 speed,so it's a 3.23.
if you want it, i got it. $200.00

[Featherburner]

Originally Posted by 91zconvert

well mine came out of a 93 6 speed,so it's a 3.23.
if you want it, i got it. $200.00

Are you sure? 93 6 speeds came with 2.73 too.

[91zconvert]

Originally Posted by Featherburner

Are you sure? 93 6 speeds came with 2.73 too.

i was going by what Blacdout96 was saying, but if you want i could go check it to be positive.

[Blacdout96]

My info is based off of 4th gen v6 cars only. I believe with v8's you had a choice of 2.73, 3.23, and 3.42 for manual 6speeds, but don't quote me on that.

91z, if you want to see what ratio you have, make a mark on the axle, and a reference point. Then make a mark on the pinion shaft where the u-joints connects to the rear. Now turn the pinion and count how many times it takes to spin that to make the axle line back up with the reference point. (A.k.a, 3
1/4 turn - 3.23, 3 1/2 - 3.42, a little less the 3 turns - 2.73) and there you have your ratio.

Richduty, you say you have 3.42 non posi? Either the posi unit is bad, or the info is wrong. All 3.42 4th Gen rears were posi, either auburn LSD (lt1 & y87 rpo) and zexel (ls1 & y87) so unless the guy put 3.42's and no posi, I'd double check. Do the following test I stated above to double. Check. And 3.42's change the speed minutely at best. I put 3.23 from 3.08, and notice minimal change in speed to actual speed.

[eagz28]

I did just that stiil have the disc setup.If you change to the disc setup you have to add hoses to the rear & change the master.