Adapting the SM420
to
Jeep Transfer Cases
The GM SM420 is a popular transmission for the Jeep transfer cases, listed below:
Dana Spicer Model 18 (Jeep & IH, 1941 - 1971):
The Dana 18 is found in 1941 -1971 Jeep vehicles. It is also found in IH Scout trucks. It's production spanned 30 successful years, making it one of the most famous and recognizable transfer cases of all time.
Dana Spicer Model 20 (Jeep & IH, 1962 - 1979):
The Dana 20 is found in 1962 -1979 Jeep vehicles. It is also found in IH and Ford vehicles as well as a limited run of GM trucks in the early-mid 1970's. The Dana 20's design was outstanding and remains one of the strongest and most refined of all the popular transfer cases.
Dana Spicer Model 300 (1980 - 1986):
The Dana 300 is found in 1980 -1986 Jeep vehicles. It is one of the most respected transfer cases and is regarded as the gold standard by casual Jeepers up through the enthusiasts. While only provided in 1/4 Ton rated Jeeps, its strength surpasses this duty.
New Process 208, 219, 228 & 229 (1981 - 1991):
In 1980, the full-size Jeeps made a major shift in Jeeps 39 year history to a driver's side front differential and the widespread use of chain-driven transfer cases. These part time, chain driven transfer cases include the New Process 208, 219, 228 and 229 models.
New Process 207 (1984 - 1987):
The part time, chain-driven New Process 207 is found in 1984 -1987 XJ's and the 1987 YJ. The NP207 was the first transfer case that Jeep referred to as the Command Trac option.
New Process 231 (1988 - 2006):
The part time, chain-driven New Process 231 transfer case was introduced in the 1988 model year and is found in Jeep YJ's, TJ's, XJ's and MJ's.
New Process 242 (1987 - present):
The full time, chain-driven NP242 transfer case was introduced in the 1987 model year. The 242 premiered in XJ's and MJ's as the SelecTrac option. It was also used in 1991 -1998 ZJ's. The 242 persisted throughout the full run of XJ's and MJ's and continued on in the 2002 KJ.
New Process 241 (1987 - present) and 241OR (2003 - present):
The part time, chain-driven NP241 transfer case is found in 2007 - present JK's as well as 1987 - present Dodge and Chevrolet vehicles. The part time, chain-driven NP241OR RockTrac transfer case was introduced in the 2003 model year and is only found in the upgraded Rubicon package of 2003 - 2006 TJ's and 2007 - present JK's, sporting a 4:1 low range gear set.
Aftermarket Transfer Cases (Atlas and Stak):
The transfer case offerings of Atlas and Stak provide deep low range gear sets as well as customizable input, output and drop options for demanding offroad use and other specialized applications.