Rear Locker or Limited Slip Options

[gearhead313]

I'm having trouble finding information on what the rear axle is and if there is an LSD or locker availible for it. Im sure someone on here knows, i just cant find it!! Thanks guys.

[Petros]

I have not heard of one available for the Tercel, but the AE86 Corolla (rear wheel drive made from '85-'87) uses a very similar rear axle but with a larger and stronger center section. The Tercel center carrier has 8 bolts, while the Corolla uses 10 bolts to hold it to the housing. The larger diff from the Corollas have LSDs available, the Corolla GTS model (rare) even came with an LSD (as an option), and rear disk brakes. If you can locate a Corolla GTS rear axle assembly it can be swapped over (if you are lucky it may even have an LSD already in it), the axle assembly are exactly the same width and use the same suspension mounting points. You will have get a new ring and pinion to match the gear ratio of your Tercel4wd front diff since the Corolla uses a different ratio (you will need to reset the gear lash, if you do not know how to do this find expert help, if you get this wrong you will trash the diff).

In fact there are a lot of after market options for the AE86, that can be used on the rear of the Tercel4wd, even with out switching to the larger diff. The performance rear anti-sway bars, rear springs, performance bushings and shocks will all fit. By changing the axle housing over you can also get an LSD rear end, and after market performance rear disk brakes.

The trick is to fine the GTS rear end, the best bet is to find a wrecked one on Craig's list or at auto auctions (even so they are still rare) buy it for the rear axle and part out the rest. All the parts are valuable from the GTS since you can likely part it out on e-bay since those that have them are trying to keep theirs running and nice. You might consider swapping over the 4age EFI engine into your Tercel (a vast improvident in power and reliability IMO) that comes in the GTS.

I have also been told that the same year Celica GTS uses the same rear axle with the disks, but I have not been able to verify this.

So it is possible to do with simple bolt on parts, but you will have to hunt them up and change out more than just the differential.

Good luck.

[Typrus]

Our rear pumpkin-
6.2"
GTS Rolla rear pumpkin-
6.7" I believe
Early Supra-
7"
Later Supra-
8" (IFS)

Torsen would be SWEEET.
AKA Trutrac

[SynthDesign]

Our rear pumpkin-
6.2"
GTS Rolla rear pumpkin-
6.7" I believe

Correct.
I have not found any options towards upgraded swap in diffs. As for swapping in an AE86 RWD rear end, you would have to have a matching ft diff. I beleive the GTS uses a 3.73:1, the same as earlier T4WD. The drive lines uses the same mounts. The biggest issue would be adapting the T4WD rear brake system to discs. I don't beleive the master cylinder could handle the requirements and may require upgrading. Also I think the GTS rear discs are about the same size as our T4WD ft discs. This might make brake bias issues.

[Petros]

You would want to up grade the front brakes, and possibly the master cyl to the same brakes as the GTS, which the Tercel badly needs.

You could also swap back the rear drums to the GTS rear axles, it appears after my own inspection that they use the same mounting bolts for the disk brakes and the drums brakes. the 4-12mm bolts around the axle that hold on the drum backer plate are used the mount the disk brakes too, so it should be able to be swapped back and fourth. I would go disks.

[4wdchico]

Our rear pumpkin-
6.2"
GTS Rolla rear pumpkin-
6.7" I believe

Correct.
I have not found any options towards upgraded swap in diffs. As for swapping in an AE86 RWD rear end, you would have to have a matching ft diff. I beleive the GTS uses a 3.73:1, the same as earlier T4WD.

Pretty sure that the stock gear ratio in the GTS AE86 was 4.3:1. At one point I had three of those cars.

[SynthDesign]

I have a Cusco 1.5 way Rwd helical lsd for an AE86 and the paper work states 3.37:1 .
Just what I have. I could be wrong and often am.
Until someone tries it it's it , it's all really just speculation. Right

[4wdchico]

Just limbered up the old account at club4age.com. The 4.3:1 ratio for the ae86 GTS is correct. The 4ac equipped SR5 version came with a 4.1:1 rear gear set. My guess is that the SR5 ae86 axle is the exact same unit that is in the '85 & up Terc 4wd, drum brakes and all. So, it is a long shot, but did anyone ever make a LSD unit for a SR5 ae86 rear diff?

[4wdchico]

Ok, check this out: http://forums.club4ag.com/zerothread?id=19688&page=1

Just remember that if you are spending $1680 for one of these to be fabbed up for you you want to make really sure that it will fit into your terc 4wd. Also remember that the bolt circle diameter of the ae86 is about 12mm bigger than the Terc as well.

[Petros]

A quick check of the center diff carrier is that my '84 Tercel has 8 bolts holding the carrier to the axle housing, and the larger AE86 carrier has ten bolts. I have not closely inspected a diff on an '85 or newer Tercel 4wd, but next time I see one I will take a look at the rear axle, it would be interesting if the '85 and newer use the same rear axle assembly as the AE86.

A used LSD from an AE86 typically sells for about $300 on e-bay (or so I am told) and I know someone who wants $600 for a whole AE86 GTS rear axle assembly, including the disk brakes and a LSD in the axle. More than once I have considered getting it, but complete wrecked Corolla GTS come up regularly for about $800. So $600 for just the axle seems a bit steep.

But I will keep my eyes open for one.

With an complete GTS rear end with an LSD, upgraded front brakes and a 4AGE swap in my Tercel, would I have a "Tercel 4wd GT-S twin cam"?

A nice thought. That is what I am working towards.

[SynthDesign]

With an complete GTS rear end with an LSD, upgraded front brakes and a 4AGE swap in my Tercel, would I have a "Tercel 4wd GT-S twin cam"?

A nice thought. That is what I am working towards.

Ya that's the ticket.

[Typrus]

Biggest deal is working the front setup. From dedicated RWD to work with the FWD. Disc offset? Anything like that?

My 84, 85, 86, and 87 all had the same rear axle.

Doesn't the GTS weigh less than a T4wd? If so, to give the Terc the same power as the GTS with its brakes still results in underpowered braking. Maybe look into how big earlier Cressida brakes are? Or Supra? They use the same 114.3x4. Not to mention I'm pretty sure the 5M-E and 4M/4M-E still have that 7" rear end. Drums, yes, but much bigger. Can't remember what the 5M-GE ones have. Probably disc for the Supra, and I'm pretty sure its still a solid rear end. And I think its the 7". And what about the front discs?
(does some web browsing... )

Hmmm...
84 Supra
Front
Rotor Specifications:
Type: Rotor
Number of Bolts/Holes: 4
Bolt Circle Dimension: 3.937"
Discard Thickness: .748"
New Surface Thickness: .785"
Outside Diameter: 10.16"
Overall Height: 1.026"
Vented/Solid Design: Vented
Composite Design?: No
Outer Bearing Cup Included?: No
Inner Bearing Cup Included?: No
ABS Sensor Ring?: No

(has the dual-bolt style as in the early Corolla Tercels, the rotor rests under the hub to which the wheel bolts it would appear)
-----------------------------
rear
Rotor Specifications:
Type: Rotor - w/ Parking Brake Drum in Hat
Number of Bolts/Holes: 4
Bolt Circle Dimension: 4.5"
Discard Thickness: .669"
New Surface Thickness: .71"
Outside Diameter: 10.475"
Overall Height: 2.375"
Vented/Solid Design: Vented
Composite Design?: No
Outer Bearing Cup Included?: No
Inner Bearing Cup Included?: No
ABS Sensor Ring?: No

=====================================================================================
86 AE86 GTS
Front
Rotor Specifications:
Type: Rotor
Number of Bolts/Holes: 4
Bolt Circle Dimension: 3.425"
Discard Thickness: .669"
New Surface Thickness: .71"
Outside Diameter: 9.215"
Overall Height: 1.5"
Vented/Solid Design: Vented
Composite Design?: No
Outer Bearing Cup Included?: No
Inner Bearing Cup Included?: No
ABS Sensor Ring?: No

--------------------------------------------
rear
Rotor Specifications:
Type: Rotor
Number of Bolts/Holes: 4
Bolt Circle Dimension: 4.5"
Discard Thickness: .354"
New Surface Thickness: .392"
Outside Diameter: 9.08"
Overall Height: 1.855"
Vented/Solid Design: Solid
Composite Design?: No
Outer Bearing Cup Included?: No
Inner Bearing Cup Included?: No
ABS Sensor Ring?: No

====================================================================
84 T4wd
Front
Rotor Specifications:
Type: Rotor
Number of Bolts/Holes: 4
Bolt Circle Dimension: 3.937"
Discard Thickness: .394"
New Surface Thickness: .4"
Outside Diameter: 9.567"
Overall Height: 1.54"
Vented/Solid Design: Solid
Composite Design?: No
Outer Bearing Cup Included?: No
Inner Bearing Cup Included?: No
ABS Sensor Ring?: No

------------------------------------------------------
rear
201mm diameter
(all I could get and I don't want to go pull a wheel...)

[Petros]

I have been told the MR2 brakes will swap over to the Tercel, it has 4 wheel disks. The earlier (pre '87) MR2 mk1 has smaller disks than the later ones, and they are a bolt-on up grade for the earlier MR2. Both have vented front, solid rear. The rear disk appears to be the same as the Tercel front (243mm dia x 10 mm thick). By the looks of it, these are the same brake assembly as listed for the GT-S. What a shame, consider how light the MR2 is compared to the Tercel. Toyota should have known better.

I want to get a closer look at them before I commit, but the later MR2 brakes look like the hot set-up for the Tercel. Near as I can tell from pictures, it appears the rear caliper mount bolts on the the same bolt pattern as our drum backer plate. So it might just bolt right on to the end of our axle housing, replacing the drum backing plate. if so I am going this route. Does anyone know if the GT-S or the MR2 has a different master cyl. diameter than the Tercel. It might be worth swapping the master cyl. as well.

here are the MR2 mk1 brake specs:
----------------------------------------------------------------------------
Rotor Diameters:

85-86
F:244
R:239

87-89
F:257
R:262


1987- discs are:
Front - 258mm, 22mm wide vented
Rear - 263, 10mm wide solid

pre 87 is:
front - 243mm, 18mm vented
ar - 239mm, 10mm solid

Pre-1986
Piston size front - 45.90mm
Piston size rear - 33.15mm

More information may also be found here...

http://www.mr2oc.com/showthread.php...12126#post12126

[Typrus]

Even if the bores are the same, the areas of the primary and secondary circuits, stroke or whathaveyou, might be different?

I think our pads and calipers are the same as the early MR2? Just different bracket or something? Well, pads I'm 99% sure on.

I think the Mr2 or Celica/Supra brakes (assuming they could be adapted) would be awesome. If we did the Celica/Supra setup, traction would then become the factor over stopping power. 205 widths might be mandatory? Well, they handle much better anyway, so why not? lol

But disc offset is something to consider also...


I seem to recall the MR2 swap consisting of getting the mounting bracket and the rotor, as well as the hose? Pretty simple?

[Petros]

Even if the bores are the same, the areas of the primary and secondary circuits, stroke or whathaveyou, might be different?

I think our pads and calipers are the same as the early MR2? Just different bracket or something? Well, pads I'm 99% sure on.

The braking power is purely a function of the bore dia ratio between the master cyl and the caliper. So stroke is irrelevant anyway.

If the early MR2 brakes can swap onto the Tercel, than the later larger ones should swap over too. Many have swapped the later (larger) MR2 brakes onto the earlier MR2s to improve the brakes, so it seems to me these larger brakes should fit on the Tercel too. Also there are lots of aftermarket performance brakes sets available for the MR2 and the AE86, really cool slotted and drilled rotors with aluminum hubs, so it seems these can be fit to the Tercel as well. I am looking into that now, it would be hot to have 4 wheel disks with cross-drilled and slotted rotors showing through your custom alloy wheels on our Tercel. That is what I want! I have had it with the wimpy brakes on my Tercel. For long steep roads i have around here they are just too flimsy.

BTW, I read on another old thread that the Supra rear axle has 4.1 ratio and came with an LSD rear end and it can be swapped with the AE86 (a popular upgrade). IT also has rear disks. That means it should fit in the Tercel, but it would be a real stout rear axle, and it likely would add some weight. Do we really need that much strength? Has anyone trashed a Tercle rear diff/axle? I have not seen it. On the plus side, Supra rear ends should be easier to find than GTS rear axles.