Bound T-Case

Jp Magazine - - Your Jeep -

I have a ’53 M38A1 and have a prob­lem with it. When I shift it into four-wheel drive, it will not shift back to two-wheel drive un­less I raise the Jeep up off of its wheels. On the lift you can run through all the gears and in and out of four-wheel drive and the trans­fer case high and low range. If the Jeep is on the ground,

I can use all gears and high and low in two-wheel drive, but when I en­gage the front axle, I can go through all of the gears in high or low, but it will not let me dis­en­gage the front axle un­less I pick up the wheels off the ground. The tires are the same size and the gear ra­tio is the same in the front and rear axles. Do you have any ideas what could cause this?

Richard Gun­dal

Via email

As you have noted, it’s im­por­tant to make sure that all of the tires are the same di­am­e­ter and that the front and rear axles have the same gear ra­tio. Any sig­nif­i­cant vari­ance could cause the driv­e­line bind­ing you are de­scrib­ing.

It’s not at all un­com­mon for a Jeep trans­fer case to be­come bound up. Even some late-model mod­ern trans­fer cases can be­come bound up when put into the wrong sce­nario. The Spicer 18 in your M38A1 is not at all a com­plex trans­fer case. There re­ally isn’t any­thing in­side of it that could be caus­ing the prob­lem you are hav­ing, as long as the trans­fer case gear oil is clean and not glit­tered with metal shav­ings. Keep in mind that the M38A1 four-wheel-drive sys­tem is de­signed to op­er­ate on a dirt sur­face. There is no dif­fer­en­tial in­side the trans­fer case, so the sys­tem re­quires that the tires slip at least a lit­tle when cor­ner­ing. If you are en­gag­ing the four-wheel drive and op­er­at­ing the Jeep on a hard-paved sur­face, you could be caus­ing the driv­e­line bind.

If you end up with a bound-up trans­fer case, never force the trans­fer case shifter. It can cause dam­age to the shift link­age, the shift fork in­side the trans­fer case, along with other com­po­nents. To un­bind a trans­fer case, pull the Jeep for­ward and back in a straight line once or twice on a loose sur­face and stop prior to at­tempt­ing to shift the trans­fer case out of four-wheel drive. If it’s still bound up, drive a short dis­tance for­ward in a straight line, stop, and try again. Re­peat the process un­til the trans­fer case can be shifted with­out forc­ing the shifter to the point that the shift lever is flex­ing. Shift­ing in and out of low range gen­er­ally re­quires the Jeep to be stopped, but you should be able to shift the trans­fer case in and out of four-wheel drive high range with the Jeep mov­ing at a slow speed. The only way you should be able to shift the Spicer 18 in and out of two-wheel-drive low range and four-wheel-drive low range is if the in­ter­lock pill in­side the trans­fer case is re­moved. Two-wheel-drive low range is not a shift­ing op­tion if the in­ter­lock pill is re­tained. Par­tial dis­as­sem­bly of the trans­fer case is re­quired to re­move the in­ter­lock pill.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.