Well, driving home from work today with my bullet proof this and that, running VC-4 with distilled water and heat on high both to and from work (ITS NINETY SIX FRIGGIN DEGREES OUTSIDE) I am pleased as heck the truck is running so well with the new parts.

Then I hear a little rattle as I back out of the parking lot at work, and assume it's because I backed over a small pot hole and maybe the exhaust shook.

Then I slow at a stop light and as I come to a complete stop I hear a clunk. I can tell something is not right, I pull into the nearest parking lot, a church, and feel a very odd pull as I turn. I drive in the parking lot, taking left and right turns with the wheels fully deflected. At speed around > 10mph, there is a pronounced bump coming from what seems to be the rear right, but I cannot be certain.

I attempt 4x4HIGH and LOW, and both times in sharp turns the inside rear wheel skips and drags, and at full deflection the truck does not want to go forward period. Then, transitioning back into 4x2, it continues this sympton until I straighten the wheel out, put it in park, reverse, or slowly accelerate. At which time when I get 5-10mph there is a slight bump (almost like there is a deformity in the tire, or I have a flat) and then greater than 10mph its very pronounced.

Needless to say I'm bummed but I am certain I can, with your all's help, figure this one out as well. I ended up calling a tow truck and just towed it home, because I obviously did not want to drive it home and potentially do more damage to the truck.

The brick wall I am hitting is that I really don't even know where to begin, as I know very little about this truck, and even less about it's 4 wheel drive system. The first thought to my head was the tire was flat, then I quickly determined that wasn't the case, I though bearings or hub. How can I rule this out and how can I test or determine if it's the differential, given the weird issue I am having in 4x4 and turning.

And what do you think would cause the bumping, almost a hop from the rear, going straight at speed in 4x2?

Thanks alot.

Matt

 

I have been taught that it is real hard on a 4wd system to turn at full deflection - especially on a hard surface. It will aways bind and skip when you do that.

That being said, I would begin the investigation by taking the back right wheel off and checking the brake system.

 

I think I'd pull the rear diff cover off and have a look around.
Put the rear on jack stands and get someone to spin the tires one at a time while your watch the spider gears.

 

My 05 is having an issue sort of like this. I pull into driveways or just cruise at lower speeds and it sounds like I have a peice of pipe in the bed rolling around when turning and swaying side to side. I park the truck and grab the side rails of the bed and shake the s!@# out of it and get loud clicking sound out of right rear wheel. I took everything apart (wheel,brakes) and removed axel an find nothing. Next step would be pulling diff cover and having a lookie. (STUMPED)

 

Check U joints.

 

i had this problem about a half a month ago except it was coming from the right front. i came to find out that the studs were working themselves out the back of the hub...inturn the wheel was slightly movin back and forth which made the studs catch the back of the hub makin a thud noise and then made a metal on metal as the rotor was rubbin on my wheel...all in all i had to replace the hub...

 

Done and the gears looked normal and when the tires were turned the gears looked fine. No metal shavings, nothing out of the ordinary.

Right now I have the rear right wheel off. Everything, brakes, lugs, etc., looks normal. Going to take the rear left off. If it looks normal, what should I check next?

Thanks,
Matt

 

sounds like your truck is stuck in 4x4.you will always have a bad binding/grab on a dry surface in 4x4 while turning.did you check the carrier bearing on the driveline?.

 

sent you a PM on how to check U Joints Let me know if you get it.

 

Well, I'm confused at this point.

So I followed the procedures to drain, clean, and refill the rear differential. Excellent write-up, simple procedure.

I cannot replicate what the truck did the other day. Drove it around for 10 miles today and it seems to be smooth.

Could it be that the rear differential fluid needing to be changed caused the bumping and? It was as though I had a flat tire, or as though there was a bulge in one of the tires, and now it's as smooth as before.

John, thanks for the help with the U-joints, they seemed great. No slop.

Weird. Hopefully, my posts here (questions at least) cease for a while.

 

Hopefully it was a quirk till the additive and fluid got mixed and circulated. You did add the posi additive didn't you?

 

I have not added any additives, what I read on the web page for this work was:



There was no chattering or scuffing so I did not add any. I used Mobil 1 Synthetic 74w140, and it specifically says it has the proper additives but it can accept further additives if required.

Thoughts?

 

If you have the limited slip you need to add the modifier. JMHO. Some lubricants, and I think Royal Purple is one, say not to add the modifier that it is already in their formula.

 

How much do you add, if the directions say to add 2 oz at a time until it stops binding? If it's not binding, what would you add?

Thanks.

 

I would not add any. See if you notice any issues after driving around.
little off subject MudhenGIB hows the sinister delete working out? Do you have a tuner to bypass egr codes? Djd you get any codes? Still not sure if I'm going to do a delete of egr cooler or get the bulletproof cooler.