Well I am puzzled. The front driver side tire locking up when 4wd engaged on my 1990 s10 blazer. I just installed the posilock pull cable to replace my vacuum issue now this.
My blazer is a 5 speed with manual tcase. Any ideas. Thanks

 

Can you clarify? The left side tire locks up solid, but the right still turns? Like the left one skids if you try to drive?

 

OK, So after looking over things again and more testing its not just the front tire. Its is as if the truck had two different differentials.
In other words when I began to pull forward it starts to bind up and just stops. Same in reverse. Same in hi or low. Put the truck on a lift today and everything rolls fine in 4wd.
Can the transfer case do this?

 

Does it do it in a straight line, or only turning on hard surfaces? I assume you bought it used at some point. Has the 4 wheel drive ever worked properly since you owned it? Maybe it really does have two different gear ratios.

 

I just bought it maybe a week ago. Its doing it in straight lines/ Truck only moves about 5 foot before it stops. Im going through the process of checking gear ratios now but some if it doesn't make sense



.

 

is their a tag on the ifs diff

 

Those are 3.73 gears, which seems unusual. I don't know the RPO code for them off the top of my head but, if it doesn't match the sticker, you may have found your problem.

 

GU6 Rear Axle 3.42
OK got ya. I really hope this is the problem i love this truck just want it to run and function right. engine has around 240k and still strong.

 

Yup, GU6 is 3.42 ratio. You probably still have that in the front and 3.73 in the rear. I'm not sure what came with 3.73 for you to get a front axle out of. Maybe 4 cylinder pickups?

It's probably easier to find a 3.42 rear axle, but I would try to match the 3.73 instead. You'll get a little better performance, especially if you ever plan to install bigger tires in the future.

 

Yes sir. I truly appreciate the help man. This thing has been kicking my butt for 4 days now.