Front axle engagement
duke350
11-08-2008, 02:17 AM
Just a quick question before I dive in. Got a 92 Jimmy a while ago the vacuum switch on the T-case was stuck on so I pulled the vacuum line at the actuator under the batt and plugged it for now. A few weeks ago I picked up a new switch for the T-case and put it in. Plugged in the vacuum line to the actuator, all seemed good. The front axle was not engaging though. So, I pulled the batt and tray and checked the actuator. Actuator is good and spring clip is holding the cable in place. So, I pull the shift cable out of the actuator, it moves nice and free. Pull the cable and axle engages fine. Seems like the actuator doesn't have enough movement in it to fully pull the cable.
Long story short, is there any adjustment on the cable? I didn't see any way to adjust it at the top end, so I figured if there is an adjustment it would be on the axle end. Just want to know if its something simple I can adjust, or if maybe the cable stretched and needs to be replaced or ? My girl says she doesn't need it since she didn't have it last winter (I rebuilt the tranny and had a hellova time finding the right front u-joints and didn't want to reinstall the old ones), but I like things to work properly. Anyway, any insight would be appriciated.
Long story short, is there any adjustment on the cable? I didn't see any way to adjust it at the top end, so I figured if there is an adjustment it would be on the axle end. Just want to know if its something simple I can adjust, or if maybe the cable stretched and needs to be replaced or ? My girl says she doesn't need it since she didn't have it last winter (I rebuilt the tranny and had a hellova time finding the right front u-joints and didn't want to reinstall the old ones), but I like things to work properly. Anyway, any insight would be appriciated.
old_master
11-08-2008, 08:46 AM
There is no adjustment to the cable. You might check if there's a vacuum leak in the actuator system. A vacuum leak would reduce the amount of vacuum that can be applied to the actuator and limit its motion. Start the engine, shift into 4WD, shut the engine off and make sure the vacuum at the actuator remains constant, (no leakdown). If it drops, follow the vacuum lines from the actuator back to the vacuum source, including the vacuum reservoir.
duke350
11-08-2008, 04:36 PM
Thanks for the reply. Vacuum is good. I looked at it a bit today and come up with something I didn't notice before. Cable travel is the same moved manually or by the actuator. There must be a problem in the axle. It will engage SOMETIMES through the actuator. I temp relocated the battery so I could watch the actuator, jacked up just the right front wheel and spun it by hand as she shifted from 2w to 4w. Most times it would engage, sometimes it wouldn't, travel was the exact same on cable either way. I have MOD and Alldata here, and think I remember seeing a diagram on the cable to axle hookup. When I get more time I will pull it apart and see what I find. Thanks for the tips for now.
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