You know, its strange how things change. When I bought my '79 F150, it came with Ford hubs, which were rebranded Spicers.
I Hated them. Absolutely hated them. They had made some changes to the front axle that year that meant that no aftermarket hubs would fit for a couple of years.
Instead of failing in the lock position, they always failed in the unlock position. More than once, I had to get out in the mud, and build a coffer dam around a hub, scoop out the mud, and take the hub apart to engage it.
The weak point for me, was the spring. The only hubs I had used up to then was a set of old Warn Lock-a-Matics. The auto part sucked, but when you turned the dial, it slid a pair of steel splines together. If the splines were not lined up, it would not turn all the way, and you had to rock the tire or axle to line it up.
But, if the dial went to "lock", it was darn well locked.
With the Spicers, the dial cammed the splines apart, against a spring, to unlock them. The Ford versions used a plastic cam/dial, but it did a good job unless a bearing failed and it got hot.
If you turned it to 'unlock', it was positively unlocked. But, to lock it, you just released the cam that was holding the spring back, and the spring pushed the locking splines together when they lined up.
Which was great, until you got some dirt, mud, or just thick grease in the hub. Then, it sometimes locked, and sometimes it did not. I learned to "snap" the dial to lock fast, and sometimes tap on the hub to ensure it locked.
However, I must say, I never broke anything or even caused it any damage. I just never liked the idea of relying on a spring to lock my hubs. I always wanted positive locking.
After several years, I almost by accident discovered one of the main causes for my malfunctions. The spring that they used was slightly tapered.
The Ford shop manuals showed it being installed with the big end out. One day I was sitting in front of my left front hub, engaging and disengaging it by hand with the cover off trying to figure out why it was wanting to hang up.
I figured I had a burr or something on the hub splines that was causing the locking chunk to hang. Finally I cleaned out all the grease, lubed it with a light oil, and slid it in and out.
The chunk would go in, but not always come out.
I took out the spring, and slid the chunk in slowly. No hangup. I hooked it with a wire, and slid it out. Smooth. I put the spring back in, pushed it in, and let go.
It did not slide out. I used the wire to help it, and suddenly realized that the chunk was moving out but the spring was not following. Looking closely, I saw that the outside of the spring was rubbing on the inside hub splines. Took the spring out, turned it around so the big end was in, and it fit perfectly.
The big end engaged a recess on the outside of the chunk with the big end out. But if I put the little end out, it engaged a recess on the inside of the chunk.
It fit both ways.
But, with the little end out, everything worked fine. No hangups.
I don't think I ever had a failure after that. It did not cause me to love the hubs, I still wanted hubs that engaged positively, not by spring, but I could live with them.
Looking at the exploded views of the Yukons, they have eliminated most of the flaws of the old Ford/Spicers. Different spring, shorter throw, better engagement lugs.
And they look to be much heavier than the Warn Premiums I put on the other day. And my new Warns use a spring to engage them also.
I figure either the Yukons or the Warns are reliable, with the Yukons probably being stronger.
Still wish I had an upgraded version of my old Lock-a-Matics though............
Warn is the standard for manual locking... then I found a bunch about mile marker but warn is still the preferred from what all the forums seem to conclude, just most expensive. I typically wheel by myself so trying to make my 91 as reliable as I can. Thanks again for the input.
