squeak in 4x4 mode

[krl13]

Hello
I have a 92 F250 4x4 (351W) E4OD with about 140K miles. Hearing a new squeak when accelerating in 4-wheel drive mode. Not when coasting. Squeak seems to increase (faster) with speed. This a.m. I also got the sound after taking out of 4-wheel mode but leaving the hubs locked. Sound seems to be coming from LF.

Anyone have similar experience? Bad axle, hub? Any further tests or checkout I can do for a more accurate diagnosis?

thanks and Happy Motoring

 

[Skandocious]

Welcome to the forum!

My first thought is a u-joint. Coming from the left side it could either be an axle shaft joint or a driveshaft joint, since the front driveshaft is on the left side of the truck. I'd lean more towards a driveshaft joint. Does the sound change when you turn the wheels while driving?

 

[krl13]

Thanks for the reply Sk.

If I recall, the sound gets louder on a turn - not sure. Would affirmative support the u-joint diagnosis? I can go out later for a test-drive.

 

[Raptor22]

Welcome krl!

I personally dont have experience with your issue, but there are awesome guys on here who can help you.

 

[conanski]

+1 on a U-joint. To isolate it jack up the suspect wheel, lock the hub and turn the wheel by hand. Also try aiming he wheels off center to better exercise the joint. If its lumpy or stiff then you got the right one, if it's all smooth then unlock the hub and rotate the driveshaft by hand, it should be obvious if there's a partially seized joint.

 

[Skandocious]

If the noise gets louder when you turn your tires then you can probably bet on it being an axle shaft u-joint, as opposed to a driveshaft u-joint. If the noise happens when you're driving in a straight line and it doesn't change pitch when you turn then I would put my bet on a driveshaft u-joint. There are 2 on the front driveshaft.

 

[krl13]

OK, I'll be under there this weekend. Will let you know results. Thanks.

 

[krl13]

Jacking up front end and spinning the wheels didn't produce any noise, stiffness or other untoward results - other than one clank from the area of the diff.

Further driveway test drive indicated noise (rattle/clank) with hubs and axle engaged and while under acceleration (any speed) forward. Doesn't do it unless it's in 4 wheel drive, doesn't seem to do it in reverse.

Have a good 4th!