Short H42 4-speed with late model 38mm split case build/tech (1 Viewer)

[orangefj45]

I thought I’d share some more tech info from our daily work here at the shop.


Earlier this week I started building another transmission and Tcase combo for a long time friend; @wngrog
The requirements for this combo going into an FJ40 build:
1981-1984 short 19-spline output H42
New OEM split case
40-series cast iron top cover
FJ60 transmission shifter
Early FJ60 Tcase shift linkage
Early pattern split case flanges, no e-braje

We started with a really good 1982 H42 core we had in inventory along with the rebuild kit and new synchro rings.
We completed the full rebuild utilizing the case and gear set. These cases have the Tcase linkage boss/threaded hole in the proper position for the early factory linkage, they also have the 4 threaded holes for a transmission mount. You could use the earlier 1975-1980 case as well but they don’t have the mount provision.
Next step was to make the late model split case work. This requires 3 fairly simple mods:
1) You can only run one alignment dowel.
2) You have to plug the factory hole below the input seal.
3) You have to clearance the front case half slightly at the forward facing side to clear the transmission countershaft bearing.

Here’s a pic of the freshly rebuilt H42 trans with one of our Sumo Gear Co full-spline input gears.

Georg
Valley Hybrids & Cruiser Brothers

 

[orangefj45]

First mod:
Plug the bolt hole below the Tcase input seal. I use a 1/4 pipe tap and plug. Super simple and takes no time at all.

Georg @ Valley Hybrids @ Cruiser Brothers

 

[orangefj45]

Step 2: remove one of the alignment dowel pins from the back of the transmission case, since only one dowel will match the machined the holes in the front of the transfer case.
Typically you do not want to remove any alignment, dowel pins. However, in this case, the transmission main shaft rear bearing and snap ring are captured perfectly in the front case half keeping everything concentric.
Saw the single pin and seven bolts that attach the transfer case to the transmission are more than sufficient.

Georg @ Valley Hybrids @ Cruiser Brothers

 

[orangefj45]

Step 3: the transfer case from case half needs to be clearance at the front face to allow room for the transmission countershaft rear bearing. This can easily be done with a grinder, cut off wheel or sanding disc.

Georg @ Valley Hybrids @ Cruiser Brothers

 

[orangefj45]

Since we’re running a late model split case, we have to change the 2-4 shift rail to the 60-series counterpart.
You also have to run the 15mm input gear spacer since we’re running a late model input gear with the built-in seal surface, not the earlier version that utilizes a different seal and 20mm spacer.

Georg @ Valley Hybrids @ Cruiser Brothers

 

[orangefj45]

Next step is to install the front case half and gear set.
The last pic shows proper gear alignment and why the 15mm spacer needs to be used.
Georg @ Valley Hybrids @ Cruiser Brothers

 

[orangefj45]

Install the rear case half and the rest of the goodies and ….. finished!

Georg @ Valley Hybrids @ Cruiser Brothers

 

[wngrog]

Pimp

 

[bottombracket]

Masterpiece.