different diff ratios on AE82 gearboxes?

[yobbosayo]

I swapped the gearbox on my AE82 liftback in the weekend... well I thought it was an AE82 gearbox but maybe it wasn't, cos the diff ratio is lower on the new one. I couldn't see any codes or anything on the 'box to identify it.
My liftback is NZ new so maybe that's the difference. Anyway, it used to cruise at 2600rpm at 100kph but now it's about 3400rpm. It's kind of better in some ways, less downshifting, but I'd still prefer to have the original ratio. Has anyone else experienced this?

Oh, we sussed out a good work-around though... on the replacement box the filler plug was well rounded and impossible to get out. So by checking the manual we saw another plug that is under the thermostat. it's the one has an allen key socket and is furthest from the engine.
A bit of grunting got it out and we just put the correct amount of oil in there (from our Haynes manual 2.3 litres). hey presto, no need to bother with that stuck filler plug

[ChaosAD]

The ae82's with 4age engines (fxgt, gti, gt etc) have lower dif ratios as the 4age engines make their power higher in the rev range.
My fxgt sits at 3,500rpm at 100kph in fifth.
Your fuel consumption wont be as good because of the higher revs. You may be able to change the diff from your old gearbox but check this first as I may be wrong.

[Mr Revhead]

bash the other plug out, use a chisel.
then you can confirm level.
last one i did took a lot more than 2.3 litres...

[CozmoNz]

ae111 gearboxes take around 2.5-2.8L of gearLUBEEEE

[ee904age]

A bit of useless info,
My 4AG runs a 4AC box and sits at 3100rpm at 100kph in fifth.

[yobbosayo]

Eh, my liftback is 4age powered. Assembled in Thames NZ it was.
So ee904ag reckons his goes at 3100 revs, and chaosAD reckons his is 3500 -what gives?! Are they imports or NZ new? I'm so confused now. Do you think a gearbox from the single cam 1.6litre engine would bolt on to the 4age cos that was my first thought. Then I started thinking that maybe the speedo drive is a bit out too, since NZ ones have a 240k speedo and japanese ones don't.
ee904ag, where did you find that code 4AC?
Oh, and the manual was for an MR2 since the library didn't have a proper fxgt manual. It said 2.3 litres of oil in two different places, once in the general maintainance section, and once in the manual gearbox section.

[TRDWGN]

I remember reading somewhere that JDM AE82 boxes had different ratios than some export models, it might not be the final drive rather the actual gear ratio's being closer....from memory the benefit was to fit a JDM box as it had closer ratios

But you know web based findings subject to the odd bit of truth so who knows!!!

[ee904age]

Sorry I should have explained.
4AC is just another code for a 4A sohc carb engine, which my car came out with. Its NZ new and Ive converted it to 4AGE but kept the std box.

[Silvergun]

I have a AE92 4age redtop that also revs highly 3500rpm in 5th at 100kph. My 3rd snchro is gone so need a new gearbox (well second hand anyway) and was wondering if anyone knows if i can do anything to get lower revs in 5th. Maybe putting in a 4ac gearbox etc??? How easy would it be??

[QikStarlie]

if you want high diff ratio, you could use a crown wheel and output shaft from a gt starlet. 3.7:1 witch will do about 3k at 100k's and 170k's in 3rd at about 8k, if your wanting to try beat the landspeed record.. vs 4.3:1 that most 4age boxes are