FJ40 1978 gearbox and transfer-case replacement

[Black Jeep]

Dear All,

My 1978 FJ40 is running like sunshine, but i already cracked 1 transfer case while mudding, gearbox is still 3 gear so i was thinking for the future to replace the gearbox and transmission with a stronger model; transfere case and gearbox are already 3 times overhauled new bearings/seals/etc;

QUESTION;
1. Do i go for 4 or 5 speed gear-box
2. The transfer case must be stronger too, pair to the gearbox.
3. Witch model gearbox and transfer case can i BOLT-ON without modifications

The problem is i live in Indonesia and modifications are not easy here, so STOCK is the safest way to go.

Tires are 35" x 11.5 x 15 extreme trackers but in 1 year i must change my tires so i want the 35" x 14.5 x 15 BOGGERS this means i need everything a bit stronger for safety...

Hope you guys can help,
Andre

 

[waiting for time]

4 speed has the same size as 3 speed, 5 speed will be longer so you need to shorten drive shaft and maybe change crosmember.
split transfercase has no E-brake so you would need a different rear axle with e-brake on drum/disc.
4 speed with single Tcase should be a bolt on job.

 

[Black Jeep]

Hi Waiting for time,

So the first gear of 3 & 4 speed is the same size? amazing, the shortening of drive-shaft is NO-PROBLEM here in Indonesia. i already broke 3 splines before, so i bought original Japan splines and never had a problem again.

So a 5-speed would be better as first gear will be smaller, I have disk breaks all round and the hand brake is still the drum type on the shaft, that never works any-way.

A split Transfer case has no E-brake? what does that mean? i would imagine a split (newer) is better and stronger then the original T-case i have now?

So if i bolt a 5 speed including split transfer case this would fit to my 1978 Engine? that means i only have to change some body-work and drive shaft, this would be NO problem.

What type of gear-case would be the best option a H55 is that the stronger one as i have now?

Thanks for your help.

 

[waiting for time]

Hi Waiting for time,

So the first gear of 3 & 4 speed is the same size? amazing, the shortening of drive-shaft is NO-PROBLEM here in Indonesia. i already broke 3 splines before, so i bought original Japan splines and never had a problem again.

So a 5-speed would be better as first gear will be smaller, I have disk breaks all round and the hand brake is still the drum type on the shaft, that never works any-way.

A split Transfer case has no E-brake? what does that mean? i would imagine a split (newer) is better and stronger then the original T-case i have now?

So if i bolt a 5 speed including split transfer case this would fit to my 1978 Engine? that means i only have to change some body-work and drive shaft, this would be NO problem.

What type of gear-case would be the best option a H55 is that the stronger one as i have now?

Thanks for your help.

Don't know about the length of the gears, meant the actual size of the gearbox. The housing of a 4 speed is the same as a 3 speed so as I understand it bolts right on. If you change to a H55 youre drivetrain becomes longer so the room between crosmember and T case can be a problem.
I have been looking at a splitcase for mine for different reasons.
I am going to replace my T case for a splitcase and therefore have to change my rear axle for one with a parking brake in the drums/discs. The shaft parkingbrake does not mount to a splitcase. I don't know if they are stronger or not. If you want to change to bigger tyres you have to look at the crown and pignon in the third members to change the reduction to adapt to larger tyres.

 

[1911]

The strongest bolt-on case you could do would be an Orion transfer case on a four-speed H41 or H42 transmission. The Orion case is cast iron and much stronger than the stock Toyota case.

 

[Black Jeep]

This is great info,

So a 4 speed H41 or H42 is a Toyota 60 series? I just Google the Orion transfer case, WHAT A BEAUTY, SUPER SUPER, sure could not find this in Indonesia...... all the gears and bearings from Japan............. man-man

A man can only dream about stuff like that, 10 or 16 spline, so the H41 has a 16 spline I'll guess?

I will be starting to search throughly for a H41 / 42 now, then the transfer case later, thanks a lot for the information 1911 & waiting for time.

I work in Brazil and live in Indonesia so just imagine if i run into something....

Black Jeep

 

[3_puppies]

he's in a different country, I think he's talking about a 3 speed transmision and a 4 speed transmision.

the 4 speed is longer than a 3 speed, also needs a different bellhousing, which would require driveshaft modifications.

H41 comes in 2 versions, one for a solid case transfer case and one for a split case transfer case. you can not use one with the other.