84 Sierra 4x4 Woes

blkfire · November 29, 2007

Hi all

My 84 Sierra developed a 4x4 problem this week and I'm not too sure where to start. When I am in 4hi (haven't tried 4Low) driving in a straight line, the truck will pull hard to the right, then let up, pull again ect. If I drive really slow I can hear one tire stop turning, then come free again. Both hubs seem to lock and unlock fine and the transfer case is engaging and disengaging fine as well. Other then the sound of the tire stopping on the snow, I do not hear anything unusual. Everything is fine in 2 wheel drive mode. Any ideas on where to start first?

skills4lou · November 30, 2007

I'd pull the front pumpkin cover and check the innards first. Sounds like you may have a broken planetary gear or something.

jedcooper · December 1, 2007

You might check your u-joints at the steering knuckle. If they are bound and not wanting to turn, they could input some steering as they rotate.

As far as inspecting your gears, you'd most likely hear a problem if there was one. Of course, it never hurts to check it out.

You have a ring gear that is in direct contact with the pinion gear. Inside the ring gear is spider gears. No planetary setup.

autopat · December 1, 2007

I'm with Jed, you probably have a bad axle u-joint.

skills4lou · December 2, 2007

You might check your u-joints at the steering knuckle. If they are bound and not wanting to turn, they could input some steering as they rotate.
As far as inspecting your gears, you'd most likely hear a problem if there was one. Of course, it never hurts to check it out.

You have a ring gear that is in direct contact with the pinion gear. Inside the ring gear is spider gears. No planetary setup.

Yep, no planetary. You'll have to forgive me, I'm hopped up on Percocet and Valium from my spinal surgery this week. I'd still pull the diff cover, but that's just me.