Jerks when in 4WD

[echopdx]

so I have 86 Cargo that I am resorting. After installing everything in.... I lock the hubs and put it in 4x4 and started to drive in first and van most has one wheel locked in the front. It jerks like when you are in 4x4 and you turn the wheels really hard.

But my van is doing that while the wheels are going stright forward.

Any help would be great. Thank you!

[Burntboot]

Ech - Are you doing this driving on hard surfaces?
These vans have no centre diff or coupling and will bind up in a straight line.

If you on loose stuff then look to your tires first, all gotta be the same type/size and similar tread depths.

BB
By the way, 4WD are 87-89 only, so if yours is a 4x4 it must be an 87

[echopdx]

Ech - Are you doing this driving on hard surfaces?
These vans have no centre diff or coupling and will bind up in a straight line.

If you on loose stuff then look to your tires first, all gotta be the same type/size and similar tread depths.

BB
By the way, 4WD are 87-89 only, so if yours is a 4x4 it must be an 87

Yes I tried on a hard surface... is that bad? Ok I will check tires... thanks for the feed back!

Could it be one of the manual locking hubs? The tire makes one full turn before it binds... only one side. it did it twice and I stopped. I am not sure left or right.

Thanks again.

[Burntboot]

Bad? Yes, it will destroy the van.

Reading the owners manual will explain all you need to know on how and when to use 4wd.
If you absolutely must, you can drive very short distances in a straight line but even slight variations in tread depth can cause binding of the drivetrain, without that tension having some place to go, bad things will happen.
If you really need to do some testing, better to have it well secured on jack stands so the wheels can spin freely and diagnose from there but there are serious safety considerations to observe in doing that sort of thing.

There are all sorts of things that can cause issues with wheels binding, but first you have to ascertain if the issues are self inflicted or
that defects exist with the truck.
There are lots of threads on wheel bearings, stub axle bearings, axles & hubs, brake issues…….perusing some of those may answer many of your questions.
BB