LSD for front and rear of tercel?

GTSSportCoupe · Post by **GTSSportCoupe** » Mon Apr 05, 2004 5:25 pm

What would really make the tercel unstopable would be LSDs (limited slip differential) installed in the front and rear of the tercel. I'm wondering if it would be possible to merge the parts from an AE86 LSD with a AL25 open diff such that you have a LSD that fits in the tercel with the tercel gearing? I'll have to compare the rebuild notes in my two FRMs (AL25 vs. AE86). I'm thinking that it might at least be possible in the rear. For those who don't know, the AL25 rear end shares parts with the AE86 rear end.

If the above was not possible, I wonder if it would be possible to go with a phantom grip LSD setup?

I'll look into this more.

3A-C Power · Post by **3A-C Power** » Mon Apr 05, 2004 5:51 pm

I'll bet you I've spent more time thinking about possible Tercel differential swaps and comparing parts diagrams than anyone else. The GT-S diff is 6.7" and the Tercel rear is 6". I don't know about the Tercel front but it's probably the same size as the rear. If it physically fits the housing, we could use different size side bearings to make it fit the bearing caps. The Tercel's front pinion gear is unique so you would have to use it, or custom make one with the same splines in the end. I have some plans in my head of how it might be possible to cut the differential housing off of the Tercel's bellhousing and weld on some mounts for a Supra or Cressida IRS rear diff housing. The Supra rear already has LSD and a 4.1:1 ratio.

WeirdAl · Post by **WeirdAl** » Mon Apr 05, 2004 6:23 pm

if you need an empty front differential housing to play with, I have my original just sitting here.. the differential grenaded with < 50k miles, which is how I ended up with the car!

aznflick · Post by **aznflick** » Mon Apr 05, 2004 11:15 pm

by chance isnt there a possibility of using a ae86 tranny and rear axel /w lsd fit into a the tercel so then you could make your car all time rwd. I could be wrong because this is only under the assumption. I got this wheelbase figure that the tercel wheel base is only 30mm longer then ae86

3A-C Power · Post by **3A-C Power** » Tue Apr 06, 2004 1:04 am

The problem with the ae86 transmission is that the Tercel transmission has the output shaft much lower than the input shaft because the engine goes on top of the differential. To get a regular rear wheel drive transmission to fit, it may have to be moved down. There's probably a way to squeeze it in there. Yes, the Corolla GT-S rear axle will fit in the Tercel. The rear suspension is the same. It's an easy way to get LSD and rear discs. I'm thinking of doing another Tercel wagon with rear wheel drive and lots of power for drifting, while my 20valve 4WD will be an all around good car.

WeirdAl · Post by **WeirdAl** » Tue Apr 06, 2004 6:18 am

I actually did make my car rwd only by running it with the gutted front diff, but the problem was what to do with the front drive shafts, lol.

GTSSportCoupe · Post by **GTSSportCoupe** » Tue Apr 06, 2004 3:03 pm

Haha! I've thought of doing that for fun! The perfect thing to have would be selectable RWD/4WD rather then FWD/4WD. Hopefully 3AC-Power will have the time to design and test a system to make this happen.

aznflick · Post by **aznflick** » Tue Apr 06, 2004 4:00 pm

so this mean i could install an ae86 engine+ tranny + rear axel to my tercel hatchback or will i face problems with the tranny

icE · Post by **icE** » Tue Apr 06, 2004 4:08 pm

rwd/4wd switch...that would be awesome!!! What about all wheel drive

GTSSportCoupe · Post by **GTSSportCoupe** » Tue Apr 06, 2004 5:02 pm

aznflick, why don't you just by an AE86 instead?

3A-C Power · Post by **3A-C Power** » Tue Apr 06, 2004 8:37 pm

The rear end is completely different on the hatchback. It's independent suspension instead of solid axle. That's why the guy who did it used an independent suspension rear end from an rx-7. If you had a wagon for parts, you could cut out the lower body sections in the rear for the solid axle suspension mounts and weld them into the hatchback. It would be lots of work, but not very expensive in parts. The ae86 transmission would fit but you might need to lower the engine.

aznflick · Post by **aznflick** » Tue Apr 06, 2004 9:07 pm

Im kinda limted in cash and i wasnt lucky/fast enough to buy the ae86 for 200buck in vancouver. so if these parts are cheap in the junk yard ill be glad.

3A-C Power · Post by **3A-C Power** » Sun Apr 11, 2004 4:24 am

I can't wait till I can start fooling around with my spare trans and rearend and check out the differentials. For the rear, it must be easier to use a GT-S rearend with LSD than to find a 6" diff that fits the Tercel axle. The Tercel's front I noticed is so small, the ring gear must be even less than 6" diameter. Thus there would be a power handling advantage in switching to rwd and never putting 100% torque to the front.

The AE86 rears are really expensive these days because the wreckers know what they're worth and plus they all have 4.3:1 stock gears. The 79-81 Supra rear fits the AE86 easily enough, so it should fit the Tercel just as easily, and the 82-86 Supra LSD fits that axle. Given that there's lots of 82-86 Supras in the junkyards, it may be cheaper to find an early supra axle and put the LSD in it. Except that 79-81 Supra axles might be just as bad as the AE86 ones. But even so the 82-86 Supra rears had stock 4.1:1 ratios, same as the Tercel, so you can knock off the cost of a new gearset which is probably more than the supra axle and LSD would cost you.

LSD's are pretty complicated but I don't think copying the Kaaz design or something else that's good would be too hard. I would have to machine the carrier out of a big bar of steel, and then internal parts from a rebuild kit could be used, machined down when necessary to fit the smaller housing. The biggest challenge in making an LSD would be of sourcing or making all of the intricate parts for a reasonable cost.

takza · Post by **takza** » Mon Apr 12, 2004 5:32 am

GTSSportCoupe wrote:What would really make the tercel unstopable would be LSDs (limited slip differential) installed in the front and rear of the tercel.

Several ideas....some realistic...some not:

1) Weld the spider gears in the differentials...not sure you could turn very well even in mud....but hey..... problem solved.

2) A method used on the Baja bug was a double-levered handbrake setup that was sold by JCWhitney at one time. If a rear wheel was spinning...you pulled the brake on it slightly and put power to the opposite wheel.

This would actually work with the 4WD Tercel if you could lightly apply the brakes so that any tires that were slipping would tend not to slip. Could also use the rear handbrake lightly applied for the back axle at least.

Some power lost though. Try it in mud.........

3) Design a crude traction control that would apply the brakes to each wheel individually if it was spinning faster than the others....not easy.

warbstrd · Post by **warbstrd** » Thu Apr 15, 2004 9:18 pm

wait a minute! wouldnt it be easier to get the ae86 lsd rear and change the differential ring gear and pinion gears from 4.3 to 4.1 using toyota part number 41201-29197 ??????

heres a faq i found on club-4ag. which may mean you can get a rear end that wasnt a lsd and put it in....

"Can I put aftermarket LSD in a AE86 that didn't come with factory LSD? Do I have to do some modification?

OK, the 7mm difference is due to some production suppliers having different specs. Both axles were used and on AE86 throughout the production cycle. Aftermarket supplier LSD (KAAZ and Cusco) will accept both and is built with enough clearance to cover for pinion offset differences as well. Interestingly enough, OEM (race version) TRD 4 pinion units did not clear the longer axles. The axles should be shaved about 5 mm in this case to fit correctly. Aside from this problem, the only difference would be between 1984-85 axles being smaller than 1986-87 differentials. So buy the proper LSD for your year and you are all set."

now comes a question... you get the non-lsd rear, then change the ratio to 4.1. can you install the kaaz lsd into your now 4.1 rear?