whining noise when wheel unloads.

[kurama49]

Hey guys, i just recently bought a 06 FX4 and lately its been making this funny noise..

If either of the wheels are unloaded, i hear a whining noise from the rear axle, and if i back up theres a slight pop noise? other than that the truck hums along fine, theres no jolting or such, only when you just take off.

Also with this truck being a FX4 shouldent it have a torsen LS? not open diff?

Plus it has a chrome diff cover which makes me think the rear might have been messed with before.

 

[swynx]

have you tryed setting the e brake and backing up/ going forward. ive had them stick before and bang and what not.

 

[Explorin94]

Take the rear cover off the rearend and inspect the carrier bearings and well as everything associated with it.

 

[SenorNoob]

I second the parking brake statement. Sounds exactly like mine and I know it's pretty bad. I just don't wanna spend the money to fix it when the disc braked 8.8 is here just about ready to go in...

 

[4x4junkie]

Also with this truck being a FX4 shouldent it have a torsen LS? not open diff?

Only if it's a "Level II" truck (you didn't mention).

 

[kurama49]

sorry for the late reply,

The E-brake works fine, i actually just had this checked out by my mechanic when he put my new brake shoes on

The truck is not a Level II sadly

And what gear oil should i put in? and does it require LS fluid?

I'll try to see if i can get a video with my go-pro tomorrow to let you guys hear the noise better. the whine turns into a grind/growl if you accelerate hard, like if your trying to say pull out into busy traffic.

 

[dla]

sorry for the late reply,

The E-brake works fine, i actually just had this checked out by my mechanic when he put my new brake shoes on

The truck is not a Level II sadly

And what gear oil should i put in? and does it require LS fluid?

I'll try to see if i can get a video with my go-pro tomorrow to let you guys hear the noise better. the whine turns into a grind/growl if you accelerate hard, like if your trying to say pull out into busy traffic.

I would assume that the pinion has loosened, probably because the bearing is bad, and that probably because it is running with little or no oil in it.

So pull the cover and see if there is any oil in it, and look for sparklies in any oil that drains out. Backlash is near impossible to measure without a dial indicator, but grab the ring gear and rock the carrier back and forth - you should feel a very small amount of movement. If it clunks back and forth with a lot of slop then prepare yourself for some rearend work.