« Reply #74 on: September 01, 2011, 02:07:43 AM »
pretty sure the TH400 only came behind the 401's
had a 76 cherokee chief 401 TH400 quadratrac.
i think the "smaller" eights got the 727 torque comands.
although my FSJ lore is becoming rusty...
The TH400 and TF727 are both officially rated at 450 ft/lbs. Today there are more 401 V8s in front of TF727’s than TH400s because the TF727 has many more axle and transfer case options. To make your Jeep off road capable the first step is to eliminate the TH400.
The only reason the GM TH400 ended up in AMC vehicles was because it was the only transmission that worked with the Borg Warner quadratrac transfer case. This was the first full time transfer case with viscous coupling and AMC always wanted to be ahead of the curve. AMC put quite a few TH400s in full size Jeeps, and they also put a few of them in CJ7s in 1977 to 1979. Some of those CJ7s were 304s, but most of them were 258s. These Jeeps do not have locking hubs, they are actually full time 4WD. Most of them did not have low range. The low range was a big hump added to the back of the transfer case as an option. The rear axle behind a TH400 is not centered because the driveshaft is offset to the passenger side to make room for the optional low range assembly. The first time I looked underneath my 1978 CJ7 I was totally confused. Its a very strange transfer case.
The TH400 is not an option for an AMC Eagle. Its output shaft is hideously long and the bolt pattern is bizarre. It’s not easily adapted to Jeep transfer cases because the adaptor is either very long or the transmission has to be taken apart to put in a shorter tailshaft. The only good thing about the TH400 is that it has an electric switch at the end of the dropdown cable. Thats what I call the linkage that goes from your carb throttle body to the transmission to let it know when to downshift under load. Some FSJs had an electric switch underneath the gas pedal and didn’t use a dropdown cable at all. That would eliminate the cable and simplify some carb and engine swaps. The quadratrac transfer case cannot work with an Eagle because both the front and rear driveshafts are on the passenger side. The only rear axles with an offset differential are the weak and narrow CJ7 axles or the super wide FSJ axles.
« Last Edit: September 01, 2011, 03:38:41 AM by captspillane »
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