4WD Odd Sounds

[x-dog83]

I took my 91 sport out yesterday for some light offroading.
When driving with my manual hubs locked but in 2H gear, I noticed that my front differential makes a subtile, quiet little clunky/grinding sound.
When driving in 4H it makes a loud POP sound after shifting into 4H. This POP only happens once almost every time I shift from 2H to 4H and give it gas.
It drives okay in these gears with the hubs locked except for the noise and slightly rougher feel in my seat.
I have locking differentials in front and back.
2WD with hubs unlocked (free) drives smoothe.

Is this normal?

 

[Flip4ford]

It is Possesed I will call my mother-in-law to help you - she thinks she is a SAINT!

 

[Flip4ford]

Seriously it could be a front U-joint or an axle u joint going bad or a mysterious problem in your transfer case (chain Loose maybe) or even maybe a lock out?

I would start by getting the wheels off the ground and inspect, spin, wiggle and shake everything until you find the right shaft that is giving you problems or if it is indeed in the transfer case

 

[wood1]

It is Possesed I will call my mother-in-law to help you - she thinks she is a SAINT!

Is your MIL's name Dorothy Mantooth?

If you have a locker in the front diff that is a possible cause. I would also check the front u-joints.

Jack it up and start turning things until you hear it.

 

[x-dog83]

Jacked it up and spun the wheels. It doesn't make any sounds. If that's the nature of locking diff's then so be it.. Just don't want to havta call for a recovery on the trail- pretty pricy!

 

[wood1]

That's my guess but I don't have a locker so I hope someone with one will chime in.