Stronger AE86 rear end options?

[Bazooka]

I am searching for information regarding rear end upgrades for the AE86. Now I am not all that up on the rear ends and am only just beginning to learn. From my initial quick search I am finding many people referring to Hilux, Hiace and Tarago rear ends to name a few. What I am trying to find is what would be the best choice in rear end for a vehicle that will be driven hard through a punishing 4000km safari rally without (too much) drama. My requirements are disc brake rear end, LSD and a ratio in the vicinity of 5.3:1. This will be all behind a 180-200hp N/A 4AGE with W58 gearbox.
If anyone has any sort of knowledge on what would best suit these requirements then I'm all ears

[oldcorollas]

to assist your search.
stocker AE86 is S series
JDMyo is T series (stock is 2 pin LSD, aftermarket 4pin)
F is hiace/tarago? and they have clutch and torsens and probably air locker
G is hilux and they also have clutch torsen and air locker

i vote T or F...

[Norbie]

Ordinarily I'd say a 6.7" T series rear end (from a T18 for example) would be fine for a NA 4A-GE, but it sounds like you want something fairly bullet-proof so I'd recommend going for something larger. An 8" Hilux diff will certainly take anything you can throw at it but it's massive overkill for your application and the extra unsprung weight isn't a good thing for rough roads.

I'd take the middle road with a 7.5" F series rear end, ie Tarago/Corona MkII/Crown. It's plenty strong enough and isn't as heavy as a Hilux diff, plus it's possible to get them in a 4-stud variety to match your wheels unlike the Hilux which is only available in 5- and 6-stud versions.

Most of the options listed above are drum brake only but disc conversions have been pretty well documented here.

[Sam_Q]

I dont like linking to other forums but I think this would help:

http://www.ae86drivingclub.com.au/fa...Other/diffinfo

heaps of info there if you search too. The hilux option is popular

My personal advice is that you shouldnt be blowing any diffs with that power so just fit a T series diff (trueno/t18) and the rear part of the tailshaft and then fit an lsd into it. Theres a bolt on Corona disk upgrade for the T18 that seems to be the go. I dont think much of the Trueno rear end, it sounds good on paper: disks + lsd but their LSD's are 20 years old and extemely likely to be worn to the shithouse. As for the disks they are really small in size with an amazingly tiny pad.

[thechuckster]

a "4000km safari rally" implies that this might not be in Australia - what countries does the rally go thru in case you need to source spares locally?

[assassin10000]

My personal advice is that you shouldnt be blowing any diffs with that power so just fit a T series diff (trueno/t18)

I would have to beg to differ on this point.

I blew 6 r&p's with my STOCK usdm largeport 4age and t-series 6.7"... 2nd/3rd gear drifts (4th didn't work, not enough to even keep it sideways). Rally is harder or just as hard on diffs than drifting. That's why I've gone to an F-series diff. Larger, stronger (supposedly good for 5-600 hp), but not a boat anchor like a G-series .

Andrew

[SharpTDI]

Forgive me if I am mistaken, but here in the US all 4age AE86 have the T series 6.7 rear axle factory. Is it different on your side of the water? I am not very familiar with the S series axle other than it being the 6.38" size and weaker internals.

As for the upgrade, I will also suggest the 7.5. It is significantly more robust than the 6.7 and has a wealth of available LSD options, lockers, and spools. Good luck finding one. Maybe they are easier to find over there, but I have been trying to source one locally and have not had any luck so far..

Other options would be the 8" Toyota truck axle, but this requires a little more modification because of the width, as well as mounts and a non-centered pumpkin. But if 7.5 rears are easy to come by (im thinking they may be more common over there) then I would not hesitate to go this route as they should handle rally without a problem.

[thechuckster]

F-series would be the best mix of weigh and strength - but if it's the African Safari rally that you're going to inflict on this unsuspecting AE86 and you don't have access to the TRD spares catalog that folks of rallying's yesteryear did, then anything that stock hilux parts bolt onto would be a good start.

[oldcorollas]

ahh, middle of nowhere = hilux

assassin- pure abuse will kill any gearbox and diff, regardless of strength
i am not sure why people continue to rate gearboxes and diffs based on power instead of toeque but...

Sharp, US have T, aus has povo spec S series. there are T series diffs that go in, but don7t have the (shitty) stock LSD or disc brakes.. although neither is an upgrade issue (except for the later series axles and the larger bearings of disc rear end)
the 7.5 IS the F series no? there should be heaps of them in tarago/estima as well as whatever else

[af300e]

i am not sure why people continue to rate gearboxes and diffs based on power instead of torque but...

Case in point: I've broken axles in a 1942 Studebaker 6x6 truck with a retrofitted 40hp ford diesel. Very low gearing (ie. high torque) plus big load = BANG!!

Also, why do people rate the suitability of a component using extreme situations as examples? EG. "I'm a complete animal/F'wit on the clutch and I broke a T series with a
4ac"? Not saying that everyone who breaks a T series is a F'wit, but, you get my point.

If I wanted insurance or was an animal/F'wit on the clutch, the F series from an MX13 is great as they are 1425mm wide OA, including discs/drums. This is the diff that I have setup for mine, running trutrac centre behind W57 and 3sgte. Plus you can fit ST141 live axle rear disc brakes to it quite simply.
I chose F series only because the 3S makes 300Nm at 4000rpm and I didn't want to risk a breakage on a rough launch.

If the 4age makes 200hp at 7500rpm (could likely be higher than this if it is still small displacement) the torque at those revs will be around 190Nm. Peak torque would probably be earlier in the revs, and trail off at 7500rpm so say peak is around 6000 rpm where it makes 175hp? This gives torque of around 210Nm peak.
These are only guesstimated figures, but you can see you only really need to handle maybe 200 or so Nm and because the revs are high when the engine is making peak torque you'd have to be clutch kicking at speed to peak load the diff.

This info is probably more for the benefit of road/track users. Rally abuse and remote locations would dictate use of bullet proof parts.

In other words, I'd say that for calculated, spirited, road/track use the T should be the way to go.

For a good safety margin (your situation) I'd use the F series, or, like guys have said the G for ease of availability of parts, ratios etc.

[Sam_Q]

I also factored a T series because of the limited torque out of such an engine setup but also to keep weight down. I hear F series diffs are quite heavy, not as bad if you upgrade the huge drum braks to disks though.

[af300e]

I'd weigh mine, but it's in the car. If you think about it though, everything is a bit larger, so it might weigh 15% more? say 6-8kg over a T series? You could help make that increase up with lighter wheels.........

I have to remove mine again, I'll weigh it this time.

[Sam_Q]

I would love to know for sure, next time my diff is out (T series) I will weigh it, maybe in due time we can start to get some decent figures together because I hate hearsay. Thats why I went tottaly out of my way to find out a 20V weight, too much BS figues being thrown around.

[Bazooka]

Thanks Guys much appreciated. Sounds like the F series rear end may be the way to go. As the vehicle is going to be pretty well punished we are thinking the T series may not be up to the task. Has anyone got more info about the F series such as diff ratios, LSD availability and disc brake conversions? There is a fair bit of short scattered info out there but I can't seem to put it all together into what I am searching for.

[Dimitri]

any ratio you can get for a hilux(which is pretty mucn anything), as thats what they use in the front.

lsd options are limitless also. many toyota sports cars use them, mz20/jaz70,sxe10 ect ect. so all the jap options are there. and as mentioned, its hilux front, some almost all the true trac, detroit locker, lokka ect ect options are available too.