4 Speed Trans to a 3 Speed Transfer Case?

[FloridaLife]

Recently someone I met here said they heard swapping the 3 speed transmission out for a 4-speed transmission but still using the 3-speed transfer. Case was good because the 3-speed transfer case was stronger or something? Is there anyone else out there that has done the same thing or can give me some input on that? I might be interested in doing the same thing and at least being able to get one more gear on the road If I take the boys fishing or go a mile and a half up the road to get a gallon of milk for my wife.

 

[brian]

Low range in the 3spd case is lower than the four spd low....not really worth it.
Need a bearing and a custome gear to make it work.

 

[Skreddy]

Top gear in the 3 speed and 4 speed are the same. In addition to what Brian said above, you need some bolts, driveshaft mods, 4 speed bellhousing and clutch linkage parts. Is it worth it depends on how you’ll use it.

Search function can help, as well as the FAQ at the top of the forum. Also need to see pics. Pics is good.

 

[charliemeyer007]

About 1/2 gear lower in first 4 L, no change 4H still 1-1 but you get synchro in all gears.

 

[Steamer]

Yup. I did it recently. I don’t know about any stronger but for my particular offroad wheeling setup, the small gain in lower gearing was worth it to me. If you’re just looking for an extra gear, you may be best off rounding up a 4spd transmission and 4spd T-case already coupled together and make the swap.

 

[Firemedic831]

The blue 40 i have has that exact setup. 4 speed to 3 speed t-case. but its a Orion

 

[Living in the Past]

Low range in the 3spd case is lower than the four spd low....not really worth it.
Need a bearing and a custome gear to make it work.

I used my original 68 transfer case when I switched to a four speed back in 1993. The input gear is not. Custom. It a sixteen spline with twenty-nine teeth. Was used on the four speed until 4/75. While it has the correct input gear for the conversion the low range gears in these early four speed was the same as later one piece transfer cases mated to a four speed. The low range and part of the idler gear for low range were wider gears like the next generation which all the gears were wider.

Part number for the input gear is 36212-60030 and could still be available.
My first gear I bought new (1993). Since then I've acquired a few early four speed transfer cases with this gear set. One came in my 2/79 FJ40. Believe a previous owner may have installed it thinking he had the lower low range which it doesn't. 31" tires, 3.70:1 diffs and the 1.99:1 low range doesn't even compared to my 68 with a H42, stock 3.14:1 low transfer case and 4.11:1 diffs.

 

[Green Bean]

On our 1970, I also recently went with a 4 speed mated to a one-piece 3-speed transfer case. Both were rebuilt by Valley Hybrids. Kept the vacuum actuated 4WD and dash mounted Hi/Lo shift. Had to lengthen the Hi/Lo linkage. The 4 speed transmission is about 6" longer than the 3 speed, so drive shafts have to be modified (rear gets shorter and front gets longer). You may wish to call Georg (@orangefj45) at Valley Hybrids as he can set you up with all of the parts that you will need.

 

[76FJ40]

The 3 speed xfr cases are weaker than the 4 speed xfr cases. Three speed cases came in a few iterations with the earliest cases being the weakest. I put a 3 speed xfr case in my '76 and broke it in half. I then took the guts from the cracked 3 speed xfr into an empty Orion case I found on ebay. I had to have 2 bushings made due to the difference in shaft diameters, but it has worked well for about 15 years of hard use.

 

[orangefj45]

As others have mentioned, yes, this is very doable. We have done so dozens of times, and we have all the parts in stock.

Happy to help

Georg @ Valley Hybrids @ Cruiser Brothers
Shop 209-475-8808
Sales@valleyhybrids.com

 

[cruiseroutfit]

Very doable. This page is over 20 years old but the content is totally relevant:
Land Cruiser 4 Speed Trans. to Land Cruiser 3 speed T-Case

 

[Living in the Past]

The 4 speed transmission is about 6" longer than the 3 speed,

Been a long time since I did this to my 68 but believe it's closer 3 1/2".

 

[cruiseroutfit]

Been a long time since I did this to my 68 but believe it's closer 3 1/2".

Going from memory I agree.

J30 ~8-1/2"
H41/H42 ~11-1/2"

I could measure some at the shop tomorrow but that is close.