Hi Everone - Hope someone has seen this and can get me in right direction. My early Explorer once had issues with the grey plastic teeth in front auto-lock hubs giving out (or chipping a few teeth) and my Bronco may have similar issue but have never taken apart bigger units like these. So may be totally different animal than Explorer.

We just got nailed with about 4 feet of heavy and wet snow in one night in CT. Bronco normally plows anything with no problem but this stuff is brutal. It is over the top of plow in most places from wind. Have noticed that when in 4WD and when you plow forward and then go to reverse the rear wheels spin a few turns of shaft and then front axle clunks into engagement. If you do it gentle it is no big deal but if rear on ice and it turns quick it will bang into engagement hard and un-healthy.

Had gotten stuck a few times last night and actually had to use 4WD low to get free but then put in neutral, put back in 4WD high, and drove home in 4WD high - all seemed fine. But the next morning when I went to back truck up. It would roll maybe two turns of tire and bang hard and drag front tires in snow like they were totally locked up. Turned off 4WD altogether and truck moved backwards. Turned it back on 4wd high and it seemed ok except when backing up the CLUNK (mentioned at top) was more forceful than ever after the few turns of shaft and now in forward or reverse.

Then noticed that when 4WD turned off (and even after backing up for 100 ft with it off to release hubs) you can hear a clicking or scraping sound that sounds like left front hub area. Almost sounds like brake pad scraping sound but not quite.

How similar is the front hub on this 93 Big Bronco (5.0) to the early Explorer (91) style. The slip before engagement happens now in both forward and reverse (on Explorer it was missing teeth on that plastic piece) and the total lock of front wheels in reverse after using 4WD low was a little scary. Now scraping sound as if hub stuck on. Please let me know what I am looking for - if anyone has experience with this. It is a mess around here and need truck so will have to get to this soon but do not want to freeze to death chasing wrong parts. Thanks.....

 

It sounds like a bad auto locking hub. And they are totally different, get a set of manual lockers and a Haynes or a Chilton book. They aren't hard to swap out.

 

I thought about going to manual hubs but at times when pulling the trailer, running into a slick spot, or if wife or son use truck it is easier to just push a button. My family members are not the best at remembering to do things so pushing a button is easier for them. Had bought my wife a brand new 4-Runner back in 89 and it had manual hubs and she hated "getting her hands dirty" in winter - what can you do...

Are the hubs really that much different than the Explorer concept or similar but just bigger? Was hoping if similar and the tooth ring is issue, like Explorer had (a few times), I could just get parts at boneyard and change them quick. I have a file cabinet with at least 100 manuals from cars we have worked on in the shop and think there is one for this truck. Most things on this truck have been straight forward or kind of indestructable so have not needed to look up much. Never did get a real good answer on how hot is too hot for trans fluid but most issues have been no brainers with this beast. Just hoped someone would be able to say - this is the guilty part - and I can look into getting it. It is going to have to be worked on outside in 6 feet of snow because lift (and rest of shop) full of other vehicles. So I am going to lose skin working on this and whole hub change would be brutal right now.

 

Yes, they are that much different... they rely solely on centrifugal force and, as they age, are prone to just flat failing to engage. Most folks who rely on their hubs (i.e. those who frequently find themselves in mandatory 4WD situations with their rigs) will typically not even bother to wait for the first engagement issues with them. I know I have swapped out every set of auto hubs (since having the first set fail on the side of a mountain)for manuals immediately. Furthermore, since dis-engaging these hubs is done by backing up, if you have one that is even a little bit sticky in its activation, it could easily disengage during plowing maneuvers even with the T-case engaged.

 

I seem to be getting told that I am lucky this thing has lasted this long. The last sentance from Greystreak has me the most worried. If I get stuck in the middle of the road, or someones driveway, with a big pile of snow in front of me I will be in trouble. I have had the truck 8 years and I bought it from original owner with 80k on it. I pull the car hauler, boats, push snow and generally ask it to do a lot. I pulled vans and trucks up our icy street and it does not flinch. It is at 120k now and I put FOMOCO rebuilt engine and trans in a few years ago. Would be stupid to leave a weak link since I have to count on this so much. I have had 38 back, hip, & foot surgeries so getting out to lock hubs when needed is pain but you both are right that usually when I use 4WD I am ising it for a while. In winter I usually shut it off between driveways but can leave it on. Will really have to look at the hub locks in a different way. This truck takes pounding my past trucks died doing. Two Cheby pickups I had each lasted one year and lost quickly. Have kept this - even though guys said it was lousy as a plow - because it is laughing at the last broken Cheby (still behind my barn) every year for 8 years and counting. Had no complaints with the hubs but you are right in thinking a loss of one would be a big deal. Have to think about this....