Front wheels seem to lock in 4 high only

[fidia11]

I recently tried to use my 4 wheel drive and when it engaged the front tires started hopping and skipping and the truck pulled to the side quite violently.
i was going around 25mph on a very snow covered slick road. I had a bad cv
shaft so i chalked it up to that.

Well, today I replaced that bad shaft and took it out to see if that fixed my problem....it didn't at all. I did test it on dry pavement but this isn't a normal
4wd feeling. As soon as the front diff locks in and the light on the floor shifter stays solid the front wheels literally stop the truck it will actually drag the front tires, it feels as though the front diff. sticks so badly that the wheels cant spin. I decided to try 4 low and that seems fine it engages just fine and the truck sounds normal, and you can tell the front wheels are spinning freely.

I'm not well versed in the 4x4 end of things so i'm not sure where to even start.
I swapped out the transfer case last winter and everything worked fine after the swap. I rarely use the 4wheel on my tahoe but need to get this fixed.

Just some info. I swapped the rear end and transfer case out of the exact same year and body style as my own truck. 1995 2 door Tahoe. i also have a 2 inch torsion bar lift with blocks. I thought maybe the front shafts were tweaked to much so i lowered the front down about 3/4 of and inch, the cv boots are not angled to bad( the pleats on the boots dont rub against each other). I'm guessing that I have a front diff problem or a transfer case problem.

Any ideas for troubleshooting would be great.

 

[SunlitComet]

By any chance when you swapped out the rear end you mismatched gear ratios between front and rear?

 

[Bigbody250]

I'm new to this truck but sounds like transfer case

 

[fidia11]

Just a quick update. i put the truck up on jackstands and put in 4 hi. when I let it coast in drive both back wheels spin and 1 of the front wheels spin. I spun the wheel that wasn't spinning and it would slowly go by itself then stop again. I went to the wheel that was spinning and stopped it with my hand and then the other wheel started spinning...is this normal? i would make the assumption that the front wheels should be powered by the trans case and I wouldn't be able to stop the wheel from spinning. I also put it in 4 low and neither wheel spins. I'm guessing this is why the truck seems fine in 4 low...it's not actually working.

I checked the fluid in the front diff and it looks good and is full, no metal shavings and it doesn't smell burnt or anything.

Thanks again.

 

[Bigbody250]

Yea that's normal, front diff is open... Only the wheel with the least resistance spins

 

[fidia11]

I cant determine for sure if the ratios are the same, the rear end I put in it had all the same numbers and everything as the other one. Any chance theres a way to check for sure without opening the front diff?

 

[Bigbody250]

There should be a tag somewhere on the housing with the gear ratio on it.. But you should still have 1 front wheel spinning on the front in high or low

 

[fidia11]

I just looked all over the front and rear diff and there are no tags there. The trans case has one that says 272 ratio and I know that matched my old transfer case. If the ratio of the t case is different then the rear end would I have an issue in 2wd? If it would then I can assume that the rear and the trans case are the same. I just need to figure out how to check the front diff.

 

[Bigbody250]

No as long as your in 2wd your fine but if you did happen to get a say 3.42 rear end and the front is 3.73 from the factory then I could see why you snapped a cv... I'm not sure if you can tell by jacking it up and seeing if the front wheel is spinning faster or slower than the back... That's the only thing I can think of if you can't find numbers on the diff

 

[fidia11]

Okay, I did some more digging and found that yes it should have the 3:73 ratio in the front and rear, but I cant find any info on the t case. Should the T case match the front an rear ratios? The tag on it says 272 ratio.