What’s the deal with rear brakes?

[Trunk Monkey]

Some models got rear discs others got rear drums. It’s my understanding that those with drums were non-ABS and others that had discs were the ones equipped with ABS is this correct?

In my search for a Tbird for my son I’ve become aware of this difference in some of the models.

Second question: are they easily convertible from drum to disc?

 

[theterminator93]

Thread 'Rear Drum to Disc Conversion'

May 1, 2024

Things you should think about before performing this upgrade:

• This brake conversion will give your car improved braking performance, but will NOT give you ABS. ABS is most commonly installed in cars that had factory 4 wheel disc brakes, and is not something that is simple to install.
• This conversion includes details about rear bearing replacement, pad replacement, and rotor replacement. Although I feel that it is important to replace these parts with NEW items, it is not always necessary for the conversion.
• After the conversion you may want to have the...

• theterminator93
• Replies: 0
• Forum: Brakes

• 

ABS was an option with either drum or disk rear AFAIK.

 

[XR7-4.6]

89-95 ABS and rear disc were tethered together options; if you wanted one it came with the other, no non-ABS cars came with rear discs.

1996 rear disc was uniquely optional with or without ABS, but ABS still required rear disc.

1997 all MN12s were rear disc with or without ABS


Any deviations from these scenarios were retrofits

 

[Grog6]

If you get a drum car, get a set of mark lca's and unbolt both rears at the irs, and take the whole corner.

 

[AdamG]

I have seen many early model cars with rear disc and no abs in junkyards. A buddy of mine has a 92 sport that has rear disc and no abs and his was a low mileage unmolested car so I don't think abs and rear disc were completely coupled together.

 

[1997ThunderbirdLXV6]

From the above-linked tech article: "For you V6 N/A guys, this is also a good time to upgrade your half-shafts and 7.5" differential to an 8.8"."

Why though? What's wrong with my shafts? And is the purpose of the differential upgrade another final drive ratio, or is it literally just bigger?

 

[Ericv8thunderbird]

Some models got rear discs others got rear drums. It’s my understanding that those with drums were non-ABS and others that had discs were the ones equipped with ABS is this correct?

Correct.

My 94 is equipped with rear disc from factory and I have ABS, which I’ve considered doing away with ABS..eventually.
I’ve needed a front right ABS sensor for years but haven’t been able to attain one, I ended up just pulling the ABS bulb out of the cluster.

 

[Grog6]

The 8.8 is physically larger and stronger for the sc and v8 cars.
Mark8 and sc's have a thicker halfshaft, on one side, I think the pass side.
SC's have trak loc diffs. No marks are lockers, no abs cars are lockers. Some sports have lockers; if you have jjjj springs, you should have the locker, and sc swaybar. Check the doortag to be sure. There's a decoder for the door tag in the service manual.

 

[XR7-4.6]

The 8.8 is physically larger and stronger for the sc and v8 cars.
Mark8 and sc's have a thicker halfshaft, on one side, I think the pass side.
SC's have trak loc diffs. No marks are lockers, no abs cars are lockers. Some sports have lockers; if you have jjjj springs, you should have the locker, and sc swaybar. Check the doortag to be sure. There's a decoder for the door tag in the service manual.

Only the 5 speed SCs have the one extra large halfshaft, the Auto SC, V8s and Marks all use the same thickness. Actually as far as I can tell 94+ V8MN12 halfshafts are the same as mark, mine still has the originals with a Lincoln part number tag

 

[Swamprat]

Some models got rear discs others got rear drums.

I'm the original owner of a 95 LX 4.6 with ABS and traction control.
For this model year the base was drum rear and front disk.
If you wanted ABS you had to have 4 wheel disk brakes and alloy wheels.
Steel wheels only available if it did not have 4 wheel disk brakes, supposedly for caliper clearance (at least that is what the sales guy told me at the time).
Not sure if after the fact switching to rear disk requires different tubing configuration or different proportioning valve, etc.

 

[Trunk Monkey]

I'm the original owner of a 95 LX 4.6 with ABS and traction control.
For this model year the base was drum rear and front disk.
If you wanted ABS you had to have 4 wheel disk brakes and alloy wheels.
Steel wheels only available if it did not have 4 wheel disk brakes, supposedly for caliper clearance (at least that is what the sales guy told me at the time).
Not sure if after the fact switching to rear disk requires different tubing configuration or different proportioning valve, etc.

That’s how I remember it. I’m also the original owner of my car - a 95 LX - that came with rear disks and ABS. It was the first car that I’d ever driven with ABS.

ABS was was pretty new and novel at that time. I tested it shortly after I bought the car just to see what it was about. I put my foot on the floor from about 45MPH and was really impressed with how it performed.