Rumble-Strip Noise in Front End - 1992 Pajero

[klneedham]

I have searched through the forums, but cannot seem to find a problem quite like this one.

I have a sporadic noise in the front end of the Pajero -- I think from the actuator or the front diff. It sounds like I am driving over rumble strips. It occurred first only in 2WD, now it is happening in 4WD also, though less frequently. In 2WD it can occur at any time, in 4WD seems to be only when decelerating, and it seems I can prevent it by holding on some throttle while braking with the left foot.

I have changed the vacuum solenoid, changed the diff fluids, replaced the vacuum check valve, without affecting the problem. I have no light flashing problem; 2WD lights engage just fine, very little flashing after shifting, and 4WD lights the same. I can manually move the actuator rod with engine off, though the actuator does not seem to move it by itself when engine running after shift lever is move, despite that it registers that it has shifted by the light guage.

Should I change the actuator next, or is there another step that I should take before getting a new one?

Also, I have read about the transfer case chain making noise. Is it possible that this might be my problem?

[stumagoo]

have you got any lift??? have you got an aftermarket CV???? if yes to either or both of these then jack your wagon up first on the control arm so you have no extra droop and turn each wheel.... look for signs of binding or the wheel going up and down as it turns - this has happened to me with aftermarket CV's and was worse when the front was lifted. - I also found it was words when the suspension had any extra dropout from ride height - so if I went around a corner hard the inside wheel would hang due to boddy roll and it would happen badly then. -One particular brand was sooooooo bad it happened with level CV's on acceleration and deceleration as well

[BeanCounter]

Just had a thought, how are your wheel bearings? Just asking as I recall in another thread from sometime ago that if a noise similar to yours (probably more of a grinding I guess) goes away when braking could be a sign of a bearing on its way out.

[klneedham]

I do not have a lift kit on the Paj; however, the front shocks should be replaced as they are a bit spongy. Would that make a difference, or cause anything in the front to clatter?

I had the CV joints checked today by a shop here. Mechanic did not seem to think there was a problem. But nobody is familiar with these Pajeros here in the US, so not sure if this means anything. I was wondering if it might be an inner CV joint as it only seems to happen in 4WD when decelerating, though it happens in 2WD much more often, and when accelerating, coasting along, or decelerating. Since 4WD is "natural state" it would seem to me that the CV joint would be actively engaged in 4WD whereas not actively engaged in 2WD. Does that make sense? Or is this not the way the system is set up?

[stumagoo]

One side CV is always engaged d the other is shifted on and off with the selection of 4/2wd. Here it is the left side that is always engaged but I won't say that is definitely that case for you as I wonder if the diff is flipped for the steering over there. for us the steering box side has the inner CV bolted to the shaft out of the diff. This is the side that disengages with 2 wd. that said th I auto hubs mean the Axles are always turning

[saint_nz]

I had a similar problem that gradually became worse. It sounded like the actuator was engaging or disengaging slightly and would grind in 2wd. It seemed to be ok when it was cold but after say 10 to 20km that same grind noise would appear along with 2wd flashing lights - solid lights when there was no noise.

I replaced the solenoids...all the tubes....went to manual hubs.. still had the same noise... I gave up and just switched to all wheel drive when I heard the noise....

How I fixed mine (I think lol) there was a corroded earth wire that is bolted to the passenger side of the motor....if i remember correctly may have been broken....but anyway replaced it and the noise magically disappeared....possibly coincidence ...hasn't returned and it has been year or two since.....