How to tell what gears are in front diff?

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AirmanSkee

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Alright, so its getting closer to me getting home and finally pulling my truck out of storage after 6 months.

Last year, I thought the 4x4 was working right in my truck, as when you would hit the button on the dash, you would hear it *clunk and could feel the difference in the driving (mainly in 4lo, as you could feel it pull with the lower gear). I had also not gotten stuck yet, and never realized the front tires weren't engaging til the snow hit. Right after the snow hit last Halloween, I found out and replaced my front diff actuator so my front tires would engage. Here is where my problem starts now.

When changing ranges from 2hi/4hi/4lo, it now engages my front wheels. But in either of the 4 modes, the front end starts hopping after getting up to a certain speed. The ad when I purchased the truck said it had been changed to 4.10 gears, and it is definitely reading at that for rpm/speed ranges for my tires. But the only explaination I can come up with is the front end is still 3.73, causing them to spin at a different speed than the rear.

Does this sound plausible? Or is there another explaination anyone can come up with? Im just kind of hoping to come up with some ideas to test before I tear open the front diff to find out it was something small.
 

ChrisAU

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It would be really bad on pavement. Like you wouldn't move more than few feet before the front diff exploded if that were the case.
 

AirmanSkee

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I havent gotten to try it on dry pavement yet since I didnt fix the front actuator til after the snow dumped on us up in AK. Is there any other thing that would make the front end jump like that when its engaged?
 

AirmanSkee

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Any idea how to test withough completely dropping the front diff out? Ive heard marking the tire and spinning it one full rotation, and counting the revolutions of the input shaft to the diff?
 

1997chevydriver

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What I would do is put power to the actuator (gonna have to run a couple wires) and jack up the front end (both tires off the ground) and turn the drive shaft by hand and count the turns it takes for the front tires to make one revolution.
 
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