... i give up searching web for answer and ask you guys. This must be a million times asked question.

I have diesel BJ-40 1975 with 4 speed transmission and 1968 FJ-40 with 3 speed transmission. I've heard that BJ case has 1.9xxx ratio and FJ case 2.3xxx or something. So swapping FJ case to BJ is in my mind.

i found this from web...

"The transmissions for B diesels longer input shaft with different splines and will not mate to either an F or H series engine"

Is this allways true and is it easy/possible to change FJ transfer case so that it fits BJ-40. So if someone has links or other info for this swap...

Think that 2.xxx ratio would help some with 35" rubbers.

The tranny input gear has nothing to do with the transfer case. AFAIK, all H41/42 transmissions with the J30 transfer case are 16 spline. You can either install the 3sp case on your 4sp or install the 3sp gears in the 4sp case. In both cases you need a 16 spline "transition year" transfer case input gear. More details can be found in the tech section of ih8mud.com.

Kiitos.

Kiitti vaan mutta...

Ok what is that transition year thing? Didnt find it on I8mud.com. Helvetti this English to Finnish translation is giving me a headache. When winter comes i think that i just take those trannys apart and do some "thisonegoestothat..." puzzle. When i see it then i understand...:confused:

This is what i understand:

Swapping those lower low gears to my case would be best thing to do because they say that '75 case is stronger than old FJ case. But where can i find that "transition year" 16 spline transfer case input gear? Or is it possible that my '75 LC has one??? Or is it different size or something?:confused:

'74 transfer cases had the 16 spline input gear (atleast in the states.) You can order the gear from Toyota. look under transfer case tech at IH8MUD.... You'll also need a rear axle bearing from a Datsun....

Sorry, the Toyota LC transfer case link at ih8mud.com doesn't work for some reason.

You need a 16 spline transfer case input gear that has the same size and number of teeth as the 3sp input gear (which is 10 spline). As mentioned above, this was used in only 1974 in the US, which is why it is called a "transition year" gear. If you use the 3sp case you will need a rear bearing with a larger center hole (one from a 1970s Datsun (Nissan) 210 rear axle bearing is correct. You can also machine the hole out to accept the 4sp bearing. If you use the 4sp case with the 3sp gears, you will need some extra shims for the idler gear because the 4sp case is wider.

In the US, both Specter off road and Man-A-Fre sell the gear and other parts to do this swap for about $200.

Be sure to have plenty of kosken korva when you take this apart on those winter nights.

:beer:

OK thanks for info! Now i understand this process. I think that 1.9xxx to 2.2xxx ratio is not worth of 200$? Or what do you think? I'm running 35" tires. Is there any sources where i could find lower ratio gears for stock "4speed" transfer case? Dunno what would be ideal ratio when using 35" tires.

Nobody makes lower gears for the J30 (one piece case up to 1980) transfer cases any more. You can get 4:1 gear sets for the later "split" two piece tansfer cases. They are made in Australia and cost about $1200 USD.

Another possibility is the AA rock box or Marlin Toy box reduction box between the 4sp and the stock transfer case.

In the US, the GM sm420 transmission has always been a popular way of getting lower gearing because it is 67:1, cheap and bolts to a 3sp transfer case with a simple plate adaptor.

1200$... well that 200$ for 16 spline "transition year" transfer case input gear and bearing is starting to sound very good. Did some calculation and with that fj gearing and 35" its very close to situation when using stock sized tires. Where can i find spare part number for that gear so i could ask local toyota dealer for price? And any info on years and models that has this "transition year" gear?

The months of production for the Land Cruisers with the transition gear were 9/73 thru 4/75.