My '90 BII w/150k miles has developed a problem. When I turn very sharply (as in backing out of a tight parking spot) and begin to go forward, it sometimes acts like the U-joint on the front (right side I think) gets out-of-alignment and knocks loudly for a few axle revolutions until it straightens back out. Sometimes it emits an audible "bang" when it does straighten out. After that though, it drives normally.

I'm not certain it is the u-joint - but what else could it be? When driving along at 45-55 mph there does seem to be a very faint knock from that same front end area - but it is not loud or prominent enough to fret over. So except for the problem I described above it doesn't seem to be worth fixing. I just don't want to ignore it too long and suffer a breakdown on the road.

The 4x4 locks fine when I've used it recently in the snow/ice. I don't off-road with it so seldom has the 4x4 mode been used.

Any thoughts? Are the front u-joints something that often need replacing at 150k miles? Or is there something else that could be causing this behavior?

Thanks in advance for any advice.

John

 

Hello, I think the problem your discribing is a bad CV shaft on the drivers side. It probally got a hole in the boot and replased the grease with water and dirt. Take a look at the boot if you see any tears then thats your problem. Good Luck

 

He has u-joints and not CV-joints up front.
The thing is, in 2H with the hubs unlocked, the front drivetrain shouldn't be engaged at all. My "gut reaction" to what you describe is maybe a problem with the hubs, especially if you have auto hubs. Does the noise go away in 4H? If you engage the hubs and drive in 2H does the noise go away?

 

If its a BII it has IFS and IFS uses CV safts to connect power to the wheels the U jount connects power from the trnsfercase to the diff. Hope this can help.

 

A Bronco II has axle u-joints....not CV joints.

 

Hello people we all know that the BII's have u joints in them can't believe some would think that they have cv joints. I am going to take a stab at this I had somewhat of the same problem. What i found was a wheel bearing problem. The wierd thing was that I didn't experience the noise till there was pressure on the wheel ie: turning. I would check it to be safe mine was bad and it still didn't make that much noise and when I say bad I mean bad it actually tore up the axle itself so don't delay. Like I said it didn't make much noise at all. I highly doubt that its a u-joint because like said before the axles aren't engaged you could have a bad hub and that could be where the noise is coming from. Let us know I am curious. Hope some of this helps ~ Brad

 

Even with the hubs unlocked the axle u-joint still has to move when you turn the steering. A siezed axle u-joint can cause strange steering problems. And most front axles turn slowly when you're going down the road due to friction in the grease and oil anyway.

 

Hawk,

Get under your BII at the front and look at your front UJ, rt side outer, it will be visible through the front TTB on that side. If the rubber has pulled away or is gone around the four posts of the UJ you need a new UJ.

If you go to the back side of the TTB and grab the axle shaft and can shake the shaft so the crosses rattle around in the caps, you need a new UJ. If the axle moves a bit left to right, that is okay, as long as the crosses are not moving within the caps.

The right side outer is the most likely one to go because it is the only one exposed directly to the road, weather, and light.

As someone else posted, I would most likely suspect a bad wheel bearing at this point and check that. You will need a hub tool, they cost about $20. A torque wrench is a must and a good 1/2 ratchet with a long handle. Total cost of manual, tools, parts, etc. to do this job yourself (with the torque wrench being about $50) will be about $115. It is a (messy) job you can do yourself in the driveway.

The best way to check for a bad wheel bearing is to actually look at it since it will start to be eaten away before any other check will let you know. You can try jacking that side up, put it on a jack stand, and pulling the wheel in and out. While you are at it, check the balljoints.

As for CV joints! Anyone that suggests a BII has CVJs has never even looked under any 84-90 BII.

 

> at 45-55 mph there does seem to be a very faint knock
> from that same front end area

I will address this separately. What happens (sometimes) is the needle bearings in the UJ caps will rust away so much, that there is play in the UJs. When you hit a bump, the cross rattles inside the UJ cap itself. It will almost sound like an exhaust rattle since it is in the same area.

 

I appreciate the helpful thoughts and suggestions.

Let me clarify a few things. The bumping sound I hear is not usually present. I can drive for weeks without any issue. But if I turn the front wheels hard to the left or right, as in backing out of a parking spot, then when I start to pull forward (with the steering now straight ahead) I get a knocking sound which sounds about like one knock per half revolution of the wheel. If I drive forward some (100-200 feet) something pops (loudly) and then it seems fine again. Alternatively, if I stop, put it in reverse, backup a few feet and then put it in drive, the noise will also be gone. The problem was somewhat intermittent (didn't happen every time) but lately it has been easily reproduced. I may take it by the local Ford dealership and have a mechanic render an opinion.

I'm about convinced its in the U-joint(s). While servicing the U-joints I'll check the wheel bearings for good measure.

FWIW, the 4WD hubs are automatic - and that stuff worked just fine during the recent snow / sleet storm here.

Thanks again for the opinions. If I find the true cause, I'll post results here.

John