Toyota A series differentials (~1995 onwards) ratios? can i use G series crown/pinion

[ed]

several models of the jza80 supra, and also uzz30/31 soarer utilise an A series 8" differential...

the A seires has a 10 bolt crown wheel, is 200mm outside dia (8") and is about 100mm internal dia (4")

my current diff is an A01B - ie A series crown wheel as above, 4.083:1 ratio, and Torsen LSD

What i want to find out is if any other toyota models of the 90's onwards utilises this A series 8" gearset? i'd be thinking cars like the hilux/surf/tacoma/sequoia/cruiser ??

basically im after what ratios of crown/pinion are available off the shelf to suit this A series differential. ideally, im after something like a 4.8:1

It seems these did come in variants of Aristo/crown/crown majesta but its unlikely that these cars have the ratios im after.

the other possibility is that the older G series diff gears (also 10 bolt 200mm crown wheel) can be assembled into the A series? soarer21 once described he did something like this - but the details are sketchy

incse the g series swap is possible, does anyone have some hilux/hiace crown/pinion combos lying around with a 4.5-4.8:1 ratio???

thoughts?

cheers
ed

[assassin10000]

I think this may help...
http://www.precisiongear.com/toy8v6.htm

Although, I'm not 100% it will fit. I just don't see why not. AFAIK G & A series r&p's were interchangable.

ALSO, something that may come into play is if you have the TT diff vs. N/A diff. The TT had a larger gearset. Atleast from what I can find.

Andrew

[Crambo]

Check with cambelt1, I think he said the low ratio ones had a different pinion offset.

[Soarer21]

My swap consisted of brand new from Toyota 4.556 gearset into the A series housing out of the JZX90. There was also a swap of a gearset of 4.3 ratio into another JZX90 housing. I dont recall specifically their origin though. I'm 90% sure it was supplied by a diff guy I know and he told me they were Hilux origin. In both instances the original centre was used with its original bearings intact and the bearings from the old pinion were swapped to the new pinion (With the GZ20 gearset at least as they were brand new 4.556 ratio gears) The 4.3 gears were installed using a TRD centre from a JZX81 I had because when we pulled down the JZX90 diff to fit the lower ratios it was found the aftermarket 2way installed had a bent housing from an apparent blowup prior to my getting the car.

Now the diff gears I used can be found in regular G series IRS passenger cars so that may be why they fitted up without issue. Its possible the Hilux only specific ratios are different in offset but I dont know for sure as Ive only used the above gears and as mentioned they can be found in lots of Toyota passenger cars.

[ed]

ALSO, something that may come into play is if you have the TT diff vs. N/A diff. The TT had a larger gearset. Atleast from what I can find.

the TT diff (generally speaking) is the B series 220mm crownwheel - not being discussed here

Check with cambelt1, I think he said the low ratio ones had a different pinion offset.

ive heard this too, on the 4.88 and above ratios. which is a pain if true, as the 4.88 would be a choice ratio

Soarer21 - thanks you for the clarification. are you aware of any offset differences in the taller ratios?

cheers
ed

[Soarer21]

I dont know sorry. Ive only ever played with the passenger car stuff. It may be possible that I'll have another set of used 4.556 gears coming in this week (cross fingers) if thats of any interest? Can package it with the 1 1/16th master cylinder

[ed]

thats an 11% improvement over what i have...hmmm
*interested*
what kind of $ and did you decide on a price for the 1 1/16" maso?

edit: is it possible to source 4.88 gearset?

[ed]

edit - got mixed up

[assassin10000]

Have you had any luck searching on supraforums.com?

Precision gear does make '4' different 8" toyota gearsets (3 of those are 200mm crown gears. And I'm sure you don't want the reverse cut version, so really only 2 rwd versions - the 4 cyl & the v6/turbo). The only one that lists it fitting the supra rears is the one I linked, but if the gear sets do come from a hilux if you can determine what generation/years it'd help narrow down which version.

EDIT:
According to the guy in this post the MKIII's (as do the NA/auto TT MKIV afaik) have the same r&p as the Truck v6 200mm...
http://supraforums.com/forum/showthr...ck+ring+pinion

You can also pick up a solid crush sleeve from the trucks...
http://supraforums.com/forum/showthr...ck+ring+pinion

The truck 4cyl r&p's have a different crown gear offset. Although from what some people say it can still be used in the v6 truck/mk3/mk4 NA/Auto TT diffs by shimming the crown gear to meet the pinion gear...

Basically, what it boils down to is that the link I provided above 'should' be the correct ones to work in your diff. I'd advised getting a used gearset from somewhere and comparing it to a spare set/diff.

Andrew

[Sciflyer]

My swap consisted of brand new from Toyota 4.556 gearset into the A series housing out of the JZX90. There was also a swap of a gearset of 4.3 ratio into another JZX90 housing.

JZX dont use A series diffs, they are B series

[ed]

ooohhh.... controversy! i like it!

so, now to look for confirmation of that statement sir sciflyer

[ed]

hmmm, nope, the diff codes im getting for the jzx90 etc are A01D A02D

thats a relief, had me excited there about availability of diff ratios.... and still do

[ed]

[Sciflyer]

damn Ed, got in before i could edit

I just checked, the JZX100 uses a 'B' series diff, which uses a different, smaller housing compared to the A series

So you would assume that the centres are not compatible either, despite looking almost identical (ie, 10-bolt crown, torsen, etc)



hmm would be *really* nice to have a JZX centre to compare with a Supra/Soarer one

[ed]

jzx90 is A series (the smaller (200mm) but similar brother to the B series (220mm)