CJ T-18 into a CJ
by Kirk Beasley
The standard transmission for '76-'79 CJs with 232 I6, 258 I6, and
304 V8 engines was the T150 3-speed manual transmission. Although it
is a strong transmission, its 1st gear ratio is 2.99:1. The Dana 20
transfer case used during this time has a 2.03:1 low and the typical
axle ratio was 3.54:1. This combination gives these CJs the worst
crawl ratio (21.5:1) Jeep ever built. Older CJs typically had lower
axle ratios and newer CJs, YJs and TJs have lower transfer case
ratios.
The T18A with 6.32 1st was a factory option from 1977-1979 giving
the same Jeep a very respectable 45.4:1 crawl ratio, but I was not
fortunate enough to have one in my 77 CJ5. After just a few months of
hitting the trails, I decided I had to have one. The easiest and
cheapest way to get a Jeep CJ T-18 seemed to be to find a 77-79 CJ
donor and do a transmission switch. I searched the local papers for a
couple of months until I found a winner - a rusty 1979 CJ5 sitting in
an alley and it was less than two miles from my home!
Having both T150 and T18A factory setups allowed me to carefully
compare the two and note how the factory installations differed. Some
things are identical like the center floor cover and stick boots. The
CJs frame, bellhousing, and skid plate are the same but have
additional holes drilled for different configurations. The great thing
about the T150 to T18A swap is it is a pure bolt on swap - no cutting,
drilling, or welding is required.
![](Kjb_small1.jpg)
Kirk
Beasley after swapping in a T-18
The T18A is a much larger and heavier transmission than the T150. I
don't know the T18As weight, but with the D20 transfer case attached
it broke a JC Whitney transmission jack rated at 250 lbs.