How does IFS front axle actuat?

[BobM]

I have never had an IFS front end before. Always had a straight axle with manual hubs, etc.
Now we have a 99 Tahoe with IFS. The front actuator motor and the switch on the dash are new by the PO. But when in 2WD my left front axle still turns the front drive shaft while the right axle does not. Does this mean I need a new front diff? Or is there a simple fix?
Thanks.

[desertrat67]

Nope, this is normal. Your front end has a sleeve on the right shaft that slides on and off of the two halves of the inner shaft to engage the front end. The left is never really disengaged, but since an open differential sends power to the wheel with least resistance, you never get power to the left side shaft.

[BobM]

Originally Posted by desertrat67

Nope, this is normal. Your front end has a sleeve on the right shaft that slides on and off of the two halves of the inner shaft to engage the front end. The left is never really disengaged, but since an open differential sends power to the wheel with least resistance, you never get power to the left side shaft.

Thanks for the info. I found that when the PO put new bearings in the front axles, he left an old grease seal in there too. When you tighten the axle nut, the axle would come up against the seal and lock up. His answer? He just left the nut loose enough to turn. I removed the old seal and installed a new bearing. Now it turns fine.
The reason I thought that the diff might be bad was that the wheel/tire turned very hard and I saw the front driveshaft turning when the front wheel was turned. I grabbed the front driveshaft and turned the wheel by hand and the driveshaft stayed still. I guess there was just enough friction there to make the driveshaft turn. And, of course, the new bearing/no old seal made the wheel turn normally.