GT4/Rav4 Transfer case interchangability

[joshg123]

Hi Guys and Girls,

Firstly to put this thread into perspective. I have a BG mazda Familia, the mazda gearbox's are notoriously weak. So i converted the complete driveline to ST185 GT4 running gear, using a adaptor plate and retaining the Mazda BP 1.8L engine. Made about 350whp and slipped my clutch to the buggery on the dyno when a little slip up of mine caused the wastegates not to open... Didnt even get to use race fuel or high boost .

Have since purchased a straight cut dog gearset for the box. Now a few guys over in the east and myself in the west are trying to upgrade to the later FE series of engine (2.0, stroked and bored to 2.3) in persuit of power. I am trying to chase about 600-650 crank hp.

The problem we come across, and the reason for this thread. Is the FE series of engine i want to change to, is much wider at the base of the block. With the BP engine i cut a section out of the sump and grind a little off the standard ST185 transfer case, i get away with this no problems. However i cant do this with a FE as the steel block is far wider.

I need to find a transfer case, with a slimmer profile on the engine side that is known to be compatible as a bolt onto the GT4 gearcase, ive been doing some research and im reading mixed reports about the compatibility of the rav4 transfer case to the gt4 gearbox due to a drive collar.

I require as much room as possible, i found this on ebay but suspect the vehicle it came from would run different rear diff ratios http://cgi.ebay.com.au/ws/eBayISAPI....#ht_500wt_1156

Thankyou in advance for any help or guidance you can give me, there are very few wreckers that stock any of this sort of stuff my way, and when they do they want upwards of 1000 just for the transfer case. An expensive gamble in my opinion.

Kind Regards

Josh

[jonathan yee]

i know that someone did a v6 awd gt4 once and they used the rav4 tranny case for the same reason. can't remember if they used the gt4 box or the rav4 one tho.

could always just use the 3sgte or is that too much sacrelidge?

[joshg123]

Im aware of the few in the states that have done 1mz GT4, this is where i am getting conflicting information, some have suggested you can just use a Rav4 tranfer case, some say you have to use the whole Rav4 transmission.

EDIT - I want to retain some part of the car being a mazda, and its what i know and am familiar with.

[beerhead]

I've got an early model rav4 box in the shed, up to 99 they were like a early Gt4 box.From what I read the late model 5SPD 1AZ/2AZ rav4 box is the one that'll give you more room. They've got a 4.3 lower drive though, so it'll be great for drag, but limit your top speed a bit.

[joshg123]

Thanks for your reply,

The final drive doesnt worry me, as i have a straight cut final drive at the rav4 ratio in my box of dog gears to go into the box. My issue is can that 1az/2az late model transfer, with its slimmer profile slide onto the gt4 and early rav4 gearbox. Or are there changes inside the rav4 box that prevent this