First I'd like say thanks for the help in the past, this site has been very helpful. I have a 1988 Bronco that is becoming a labor of love and is my daily transportation. Driving home the other day, the front driver's side began to roar like a wheel bearing going bad. Scooted on down and picked up two new bearings with a seal. Prest-o change-o and the job was done with a little sweat and a good bit of grease. Drove it out to the lake today and it's still making the roaring sound. So here is my questions: Could the sound be coming from the bearing inside the spindle, or the universal joint connecting the two axle halves? If it is the bearing or the unversal, then I misunderstand how the front drive operates in 2H. Does the axle shaft spin when the t-case is in the 2H position? To be honest I hope that it isn't the bearing or the universal because I'm not looking forward to removing the spindle, but if not those what could it be?

 

Check your fan clutch...it will roar when it's going bad...In the driveway, engine running, pop the hood, reach in and give the throttle a push...if the fan clutch is your culprit, you'll know it.

There may be a little axle movment in 2H...just a "free-wheeling" basically...Check to make sure both hubs are indeed dis-engaged

J.

 

If you have auto hubs, they may not be disengaging. I've never heard that spindle bearing make any noise, but it could be your problem.

I kinda lean towards the fan theory. The next time you stop the vehicle, turn off the engine, pop the hood, and try to spin the fan. You should feel almost no resistance. If it's stiff to turn at all, you've got a bad fan clutch. As jbrdrummer pointed out, the fan will roar like crazy since it's not freewheeling.

The fan clutch should only be stiff when super hot air is blowing on it (very hot day with the air conditioning on) or after the truck has sat outside all night with the temperature below freezing.

 

Checked the fan clutch and it seems to be working fine. The auto hubs were changed out a long while ago with manual hubs, besides the electronic shift on the t-case doesn't work and hasn't worked very often in the 3 or so years I've owned the Bronco. I've got a manual t-case I'll rebuild when I get a-round tuit. (Do you know anybody that sells those?) As far as the 2H operation is concerned, I thought that was how things worked. I figure this weekend I'll tear down the hub again and see if I missed anything and while I'm at it I'll rotate the tires. Sometimes tires can wear funny and make more noise than they should. Usually you can feel the abnormal wear on the tires when they do that though. If you all have any more ideas, I'm certainly still open for suggestion.

 

There was another fella with the same problem (roaring sound) ended up being front bearings...I mentioned the fan 'cause 1) it's easier than bearings, and 2) that's what solved the noise in the little woman's Lincoln... Good luck and let us know how it turns out.

J.

 

Well guess what? Found that the roaring sound is (or should I say was) coming from the t-case. It seems that the t-case has been in 4-H for a long time and the bearings are just wore out somewhere in the driveline. (Probably the spindle bearings.) Bearings are the least of the issues right now though. The other day backing out of the drive, the truck lost all gears and could not go anywhere. The transmission seemed to be spinning and I finally decided the trans was working fine but that the t-case was the culprit. Turned it off and pushed it into the drive. A few days latter I had some time to look at it. Started the truck, put it into gear and I had power. While driving, the trans acted like it was shifting just fine. The only problem was that the t-case seemed to be in 4-L and wouldn't go over 30 MPH. Each time I've tried driving it since then, the truck does the same. The truck has always had an issue with the electronic shift and it would work some times, but wouldn't work most of the time. Every now and then I'd lock in the hubs and try the switch. Most of the time there was no difference (could be because it was already in 4X4). On one occasion when the switch was pushed, the 30 AMP breaker in the electronic shift circuit blew. The electronic shift module has continued to make the clicking noise (as if it were switching) each time I've tried the push button but to no avail. It seems to be stuck in 4-L.

So now it is question time: WHAT THE HECK IS GOING ON??? This was a rebuilt t-case that I put on a couple of years ago, would it be worth rebuilding again and is it something I might accomplish myself if it needs it? How do I determine if the t-case needs rebuilding? Is there anyway to manually shift the t-case from 4-L to 2-H without having to break it down and get inside to the lockup ring on the main output shaft? Pleas help.