4x4 problem

[DGamelin]

I am a shop onwer and we have a 2006 ranger in here with a problem that we can't get to the bottom of, so I was wondering if anybody has delt with this? This truck is a meater reader truck for the power compy, no frils. 4l v6, auto, no lock out hubs of any kind axel is live all the time. 2wd, 4wd, 4wd low tranfer case. the truck has 73k miles on it.

Problem- When the truck is going 45mph or better in a straight line in 4wd about every 200 yards there is a loud and scary bang.

First we replaced the rear ujoint and the one in front to start, they needed them anyways.

The fluid in the tranfer case has no metel fillings in it. And be bcause you can't check the front diff we pulled the diff. Thinking the front spider gears might be bad. NO the inside looked good. We did replace a right axle seal and left wheel bearing.

Going by the fluid from the transfer case it was hard to believe anything was bad. But after checking and rechecking the actuator motor for the 4x4 it seams good. We pulled the case and it looks good inside.

It feels like the chain is jumping or it is jumping in and out of 4wd. But there is no sign of that inside the case. It does have matching tires.

Any Ideas?

 

[Original_Ranger84]

Are the tires at the same tire pressure?

The only other thing I can think of that might cause that could be the CV joint on the rear drive shaft. if it doesn't have good grease on it, it can start to bind.

 

[backroad101]

Are these part time systems meant to driven at those speeds in 4wd? I thought no.

 

[Original_Ranger84]

It is generally not a good idea to run it in 4x4 going that fast.... Unless on loose terrain.

 

[DGamelin]

Yes all the tires are the same. It doesn't have a CV on the rear but it does have one on the front. We haven't taken it apart yet. We did pull the cover off the rear end to look at the spider gears, they look fine.
We have ran our one ton at highway speeds pulling a loaded gooseneck from st louis to upper michigan more than once in snow storms only throwing it out for bare payment truns. Right now we have snow storms going on and haven't seen bare roads in days. People up here put them in 4wd for days on end. Like he said as long as traction is low you're fine.

 

[dennis461]

I would not compare a one ton ?? brand with a 2006 Ranger.
What state are you in? how much snow?

 

[srteach]

A 2006 is full time four wheel drive (no hubs). It is designed that way.

There seems to be a bind somewhere on this one.
When it bangs, does it jerk or pull right or left on the steering wheel? Does it jump forward or hesitate? Is there a constant vibration when moving? I assume it doesn't jump out of gear at the bang.
The only thing I can think of is internal to the transmission or drivetrain, but you seem to have checked the drivetrain.

 

[DGamelin]

A unloaded ranger will allow wheel slippage alot better then a loaded 1 ton.
I am in upper Michigan in a town called Christmas, next to Munising, about 3 miles from lake superior. I don't know how much sonw we have, but I'm plowing the driveway every day.

This is part time 4wd not full time. Has no clutches of any kind for awd. Remember these are fleet trucks, special order builds, not like the ones you and I would be able to buy.
It doesn't jerk, pull or get upset in any way no vibrations. It stays in gear and in 4wd. When the bang happens there is a thud right under your seat. It feals like the chain in the tranfer case is jumping. But there is no sign of any thing going wrong in the case. Usually when we see a chain that bad it is so loose it is hitting the case. The only thing that I see is the top drive sprocket has an unusual waer pattern. You can see how some teeth are pulling much more then others about a third. Some have almost no ware another third. I don't see sings of the chain climbing up on the gear but it is what I want to blelieve so far.

Earl43P We pulled the rear diff cover, it all looks good. Thanks

I've got to say I don't own one of these Rangers but after taking this truck apart from one end to the other, I like way its built, and I think it's holding up very well considering what these guys do to these trucks. We repair thier enitre fleet, from F750s-C7500s to cross country snow cats.

 

[railman]

i am 100% sure it is driveline bind that is causing the chain to jump....you said so yourself you have uneven wear on a 1/3 of the main sprocket...i'm sure if you were to rotate the drive train you would see that the worn spot would equate to approx. 20' in distance....

like ya said that this is not a fulltime/clutched/differentialed AWD setup...if you have good enough traction to be goin 45mph+ then ya don't need the 4wd ( my opinion ) and could switch it off...then switch it back on whenever ya below 30mph...

i would say if ya replaced the sprocket that it would no longer slip the chain...but would highly recommend them to turn off the 4wd above 35...

l8r, John

 

[DGamelin]

Well I orderd a chain and sprockets on monday. I just wish we could see something more. The front CV on the drive shaft looks like new. We will see.

Telling these guys to trun them off and on every 8-10 mintes might mean we would be putting new switch motors on every mounth besides these guys are going to do what they want.