Need help with my dads 97 expy

[Big Red Monster]

So heres the problem when he puts his truck in 4 hi and tries turning the wheels to the left the truck refuses to move. Only does it in 4 hi and with wheels turned left. Any help guys? This is real strange.

 

[Big Red Monster]

nobody at all has ever had this problem? why the hell is always me or my dad with the weird issuses...

 

[Big Red Monster]

so now on his truck when u put it in awd mode the light blinks on and off on top of the original problem. dose anyone know anything about this? we really need help no mechanic has figured it out yet and its been to 3 different shops

 

[tonydiv]

It's the left turn thing that doesn't make sense. If it was a physical interference issue, it would probably show up in 2wd.

 

[Big Red Monster]

i know it dosent make sense but now its if you turn left or right the truck will just come to a stop and not move, and if you try accelerating it feels like your gonna break something. in 2wd its fine, but in 4wd the front locks while turning, and the last mechanic we saw tried saying that this is NORMAL. how the **** is that normal are you not supposed to make turns while in 4wd? the truck never did this before so we know that hes full of crap

 

[Big Red Monster]

well ill just update this. we changed the fluid on the front differential, we used lucas 80/90w gear oil and the ford additive. it dosent lock up as much now but it still locks, were gonna have another trans specialist look at it tomorrow, were thinking its in the transfer case

 

[K5rnt]

Kinda sounds like the t-case is getting bound up. Are you trying to make hard turns in 4wd on pavement or dirt?

 

[Big Red Monster]

we tried on snow and dry pavement with the wheels at full lock, the truck comes to a stop and you cant make it move at all, it never used to do this though in all the time hes had it, he bought it almost new in 2000 with like 25,000 miles on it and this is the first time we had this problem with the 4wd

 

[toms89]

My first thought is that the transfer case is getting bound up because of difference in speed between front and rear while turning with traction. But you said it happens in snow too??

Maybe you have a bad CV joint thats binding up... but it seems to me it would do it regardless if 4wd was engaged or not.

Mine will bind up in high traction conditions such as pulling boat out of water then turning tight in 4wd. This is normal as the wheels are not allowed to turn at different speeds that they need to. This is very hard on your axles and transfer case!! I try and make sure I take it out of 4wd asap after pulling boat out of water on slippery ramp.

 

[Big Red Monster]

idk what is wrong at all its so confusing, what your saying tom makes sense but the thing that we dont understand is the truck never used to do this, and in order to get in our garage when it snows u need to use 4wd and u need to turn the wheels to full lock (our alley is tight and our garage has a 45 degree incline to get in). we are thinking it could be the cv shaft but still not sure