3 speed to 4 speed conversion

[Dutchman]

Good morning everyone!

I'm new to this forum and just want to say this is the sweetest forum I've ever seen!

Got a question for you cruiser jedi masters... I have a 1972 FJ40 with a CSB 350 mated to a ranger overdrive and a 3 speed tranny. I have taken tranny out to replace pilot bearing and I'm now contemplating putting a 4 speed tanny in. If I did this will a 4 speed trany fit a 3 speed transfer case and could I or should I keep the ranger overdrive? also would I have to alter drive shaft lengths even more than they are now?

Any input would be greatly appreciated,
Dutchman

 

[Dedtruk]

Certainly not a Cruiser master but HTH: The Toy H42 4spd will fit the three speed type TC with an adapter kit that goes for about $150. You can assemble the pieces yourself but after all the legwork, you might as well buy the kit. Yes, you'll almost certainly have to modify driveshafts since the J30 3 spd trans is significantly shorter than the H42 4spd. But I'm pretty sure the Ranger is drilled for both the 4spd and 3spd transmission front mounting patterns, so it should act as your adapter to your motor. I'd keep the Ranger, but you could swap to a conversion bellhousing if you want to use the Toy H42 4spd trans ... Or you could swap in an SM420 or SM465 4spd trans behind the Chev and use a stock Chev bellhousing, but then you're looking at an adapter to the Toy transfercase which runs a few bucks depending on whose adapter you use. It's more expensive in most cases to adapt a Chev trans to the Toy TC than adapting the Toy H42 to the Toy 3spd type TC. You'll still have to modify driveshafts if you use the Chev trannies.

It boils down to how you're going to use the rig and how much you want to spend. Serious rock crawling? Chev trans. General trail use? Toy H42. Let us know how it goes, and welcome!

 

[baja1d]

https://forum.ih8mud.com/40-55-series-tech/25612-fj40-3spd-vs-4spd-swap-not-swap.html

 

[Dutchman]

Thanks for the info. Now to decide what to do!

 

[65swb45]

Got a pic of the back of the Ranger OD? If it is 'shaped' to match the 3 speed trans, it will not fit the shape of the 4 speed.

FWIW, I recall someone telling me the Ranger was never designed for a 3 speed, and perhaps a PO just modded the OD to make the 3 speed fit, it which case it may still be useable. But that just reemphasized the need for pics.

Best

Mark A.