Can't shift into 4WD LOW only

[fouroneone]

1994 Chevy Suburban, 205K miles. I can not shift into 4WD LO. 4WD HI works fine. I used 4wd LO on occasion when off roading or going through deep snow. Just recently, I am unable to shift into 4wd LO. No matter how hard you push the floor shifter, it will go into 4wd lo. 4wd hi works fine. Any ideas.

[j cAT]

Originally Posted by fouroneone

1994 Chevy Suburban, 205K miles. I can not shift into 4WD LO. 4WD HI works fine. I used 4wd LO on occasion when off roading or going through deep snow. Just recently, I am unable to shift into 4wd LO. No matter how hard you push the floor shifter, it will go into 4wd lo. 4wd hi works fine. Any ideas.

check vacuum lines

[fouroneone]

Originally Posted by fouroneone

1994 Chevy Suburban, 205K miles. I can not shift into 4WD LO. 4WD HI works fine. I used 4wd LO on occasion when off roading or going through deep snow. Just recently, I am unable to shift into 4wd LO. No matter how hard you push the floor shifter, it will go into 4wd lo. 4wd hi works fine. Any ideas.

Which vacuum lines should I check? Do they run from intake manifold and transfer case or just some rubber hoses around the intake manifold? Thanks for your help.

[j cAT]

Originally Posted by fouroneone

Which vacuum lines should I check? Do they run from intake manifold and transfer case or just some rubber hoses around the intake manifold? Thanks for your help.

check the vacuum lines that go from transfer case front dif to intake manifold this does happen when these lines are 14years old. also check at engine all vacuum lines any cracked split hard as a rock replace. this is probably gonna be alot of lines... have you ever done this before ? must check all as they are all part of the total game plan they work as a team...

[J-Ri]

If I find a vacuum leak in a hose on a vehicle this old, I replace all the vacuum hoses. If one's cracked, chances are the rest aren't far behind. Saves future headaches to do 'em all now.

[MT-2500]

I think the 4 wheel shifting on that one is a manual lever shift and a electrical actuator solenoid on front axel set up.

If the shift lever does not go to the 4W low position the shifting arm assembley may be full of mud or rusted up.
Unhook shifting rods at transfer case shifting levers and check for 4W low by pushing the transfer case arm.
If the transfer case lever moves to 4W low.
Take the shifter assembley off and try to clean and lubercate it.
Good Luck
MT


MT