1971 3 Speed to 4 Speed /Front Disc Conversion ??s

[PSYWAR07]

I am new to the site and the FJ world and have bought a 1971 FJ to begin restoration/mods on. I have it just about stripped to the frame and will be rebuidling it from the frame up.

I am mechanically inclined but far from a gearhead.

My first question is regarding the tranny swap. I am looking to swap out the 3 speed on the column to a 4 speed in the floor. I am leaning toward the lower geared 4 speed (H41 I think). Is it a direct swap? Will it bolt into the bell housing and my model transfer case? What else will it effect (Crossmember/driveshafts) ?

I know I will need to get the top plate and shifter for my tranny and tranfer case as well (since i want to convert it to a floor shift from a vacuum).

Anything else I need to think of with this swap? If I am on track with the swap I will also be looking to buy the tranny, top plate, shifter along with the transfer case parts to convert it to a floor shifter.

My second question is about the front disc brake conversion. Right now I am leaning toward the disc brake kit from JoeTLC with the aftermarket brackets. It seems to do the conversion without the hassle of breaking apart the birfields. I just don't have any experience on any pros /cons.

I searched through the threads and could not find an exact answer, they were either too complicted or didn't have enough to answer my questions. Sorry if this has already been asked. Any help/advice would be appreciated..

Thanks...

 

[Josie'sLandCruiser]

Hi All:

The H41/42 four-speed transmissions only came as floor shift models, so if you buy the complete tranny you'll get all you need.

Yes, the H41 is the lower-geared TLC four-speed transmission.

To swap the H41/42 to the earlier type t-case will require a different input gear; the J30 three-speed tranny has a ten-spline output shaft while the 1970s-era H41/42 have 16-spline output shafts.

Regarding the front disc brake conversion, I don't know anything about the "JoeTLC" conversion kit but you really should re-build the front axle as part of this process. That will require dis-assembling the whole mess, but it is worth it.

You can leave the '71 drum brake axle installed in the rig. Just strip-out all the drum brake parts and replace them with outer knuckle parts and Birfield joints from a 1976-89 Land Cruiser or a 1979-85 Toyota 4wd mini-truck. Yes, the axle tube is the same, but the outer parts are different. And the later Birfields are much stronger than the coarse-spline units in a '71.

Good luck!

Alan

 

[green71fj]

three speed and four speed bellhousing are not the same,you'll need to cut about two inches out of the rear drive shaft, and get the right mounting flange, if the four speed is the type with the parking brake you can just swap drums from the three speed,that will give you the right mounting, it is a tight fit as the four speed and case is about two inches longer so you might have to move the frame cross member back, i did not move mine but it was a trick to get the tcase on.

 

[mooker82]

I would avoid the JoeTLC disc kit. You will still have the weaker coarse spline birfields. I am pretty sure the kit uses modified chevy rotors too, so you will have to either order their rotors each time or have a set machined. Also lots of people on here have had bad experiences with JT Outfitters (AKA: JoeTLC).

Doing the disc swap isnt too hard. There is a great writeup in the FAQ section. The front axle probably needs to be rebuilt anyways.

 

[bsmith123]

3 on the tree to 4 on the floor

You will also need to cut the holes in the tunnel cover

I had my driveshafts lengthened and shortened to the right size ---they installed a whole new pipe section and I used the 3 speed ends at the diffs and the 4 speed at the transfer case (which is just the shorter half of the 4 speed D/S)

If you are swapping the trans might as well look at the clutch and the rear main seal too

Definitely make sure the park brake is in good shape--I put in all new parts, to pull the drum requires removing the rear motor mount and dropping it down to pull it off because of the interference with the cross member

There is an FAQ on using the 3 speed xfer with a 4 speed or check out coolerman's web site (under his sig line)


with the disc conversion I am thinking of getting 2 extra rotors machined so I can always replace a set as needed and order more