transfer case help on fsj

[bdmc73099]

son has a 78 fsj auto quadra (junk) track transfer case will ingage but when driving will slip into neutral........any ideas would really help thanks

[jeepsr4ever]

Sounds like he has a vaccum problem.

You can take teh plate off that holds teh vaccum check valve its a little ball and spring. It may be the spring is weak from the case getting overheated. You can pick up a spring at the hardware store. Also it may be that his shift linkage is getting bound up. Also make sure all rubber vaccum lines are in good shape.


Good luck....I have had this happen and i does suck hopefully its something stupid-simple

[bdmc73099]

ill let him know about the plate ive got him checking all the mounts and have a vac diagram i found on the net just dont know if its right thanks for the help if you can think of anything else please let us know

[mrtazwrench]

i've also seen some that have replaced the vac system with a cable setup, it would take a little work though.

[Toy Maker]

On the QT units, neutral is in the low range reduction unit. The unit is bolted onto the left side rear of the transfercase. For it to come out of gear when driving, most likely causes would be loose/ worn/ broken engine/ trans mounts or binding floor shift linkage. Internal problems can come fron worn thrust bearings, fork/ linkage. Inspect the mounts and external linkage for problems, then, if none found, disconnect the linkage from the reduction unit, check to see if it still fallls out of gear. If so, then internal service is required. A complete reduction unit should be the simplest cure if internal problems found, as service parts are scarce.
The low range units give relatively little trouble, so questions come to mind.
When you say it slips into neutral, do you have to stop and re-engauge it? Or does it resume pulling when you slow down? Is there any noise present when it is in "neutral"? Any more information on symptoms would be helpfull.

[junkyard jim]

Just thought I'd mention that a clogged transmission filter will make it feel like it's in neutral as soon as you drive a short ways (My J4000 did the same)

[chief]

I have the same problem whit mine, it was only som lose bults to the transfer case

[junkyard jim]

I forgot that if you have loose mounts and floor mounted shift linkage, the flex will force it out of gear!