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Auto locking hubs


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Tried searching and haven’t found much info on rebuilding or repairing these. The FSM is terrible on this subject with just vague pics and not a lot of info. Since I won’t being using this truck for any off- roading I’m inclined to just roll with the auto hubs. Any good threads out there on this subject ? 

Heres some pics of what I have. The FSM shows an extra C clip that I didn’t have . The FSM doesn’t describe the “washers” well either. 

The only C clip I have was to hold the CV in place . 





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On 1/11/2019 at 8:32 AM, datzenmike said:

I've never yet heard of anyone doing anything with their auto locking hubs on their 720, only removing them and replacing with the manual ones. 


Replacing them with aftermarket hubs? Did they replace CV axles also? 

Anyone want to tell me what the outer snap ring does ?

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I am not sure whether it is a year thing or auto vs manual hubs but my manuals show the end of shaft snaprings all years. It goes on the end of the shaft and retains the drive clutch for the manual hubs and you can set axle play by using different thickness snaprings. This is per my 1981 fsm  I don't think the autos were available until later. The other manuals were Haynes going up to 1996 but are known for inaccurate info.

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Well I have came to the conclusion I will be running the auto hubs anyway. I figured out how to assemble them properly and they seem to work. For some reason my CV  axles don’t have a groove for an end snap ring, which seems necessary to run OEM manual hubs. I thought my hubs were bad because I removed them in the engaged position and thought they were locked up for good, but they weren’t .

They are actually in pretty good shape comparing to what I’ve seen. The copper thrust washer is worn on one side , but I think I can make something that will work.

The differential looked like it never saw action when I took the cover off, so I imagine the hubs haven’t seen much action either . All the teeth on the gears looked solid 



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Have a friend with a milling machine make me some bronze washers . Not sure of the exact significance of these , but they are obviously a wear item. The dimple was worn off on one side of mine . These new one is actually brass vs. bronze, because that’s what we had. Now to try and remember how to put them back together -lol.

Since these are no longer available I told my buddy there might be interest in making more for guys running auto hubs .





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Looks good but there is a massive difference between brass and bronze. Hardness wear characteristics, nobility, Brass is good for candlesticks and maybe fake Knuckles, but for loaded parts bronze! Brass is too soft, doesn't self lubricate well and doesn't do well with the elements. Tell me to go pound sand, but Brass has no business anywhere  on a vehicle or worse arguing with my customers on a boat!. If the part was bronze to begin with go with that.

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Thanks for the feedback on material. 

What about shape? 

Thickness has to be exact? It’s hard to find exact thickness in bronze to match these. Maybe within .010 to .020 can be found. 

Outside circumference shape. The nub at the top of the dimple has no significance does it? The actually dimple does though. Machining just a circle is much easier than trying to match the outside shape . I think the nub is a product of the dimpling process only. 

The dimple is suppose to face inward on the spindle assembly and ride in between the opening of the C clip correct? 


The wear of this washer(especially the dimple)  causes issues with the hubs engaging and disengaging ? It seems to take most of the wear of any item in the assembly. 

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More fun facts about auto hubs - because they aren’t all the same.




85 at the top and 83 on the bottom . The bushings(washers, spacers , whatever you want to call them) are different. The later 85 went with a bushing that has small ball bearings . That sits at the bottom of the hub, then the steel washer goes on top of that, then the hub assembly sits on that. 

The earlier 83 only has a bronze bushing that the hub sits on. 

The hubs are different heights so they DON’T interchange . The height difference is to make up for bushing differences. So you can swap everything into a cover, but can’t just swap parts. 


Notice early CV axle has no groove at the end of the axle for the C clip for  manual locking hubs, at least mine didn’t . The 85 I removed the auto hubs from did have the groove at the end for the C clip. 




More later


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pics of the bronze bushing that is probably worn out on most hubs. Both the 83 and 85 had one side toasted. The dimple gets worn off . The dimple is what holds the bushing in place . Why it needs to NOT to rotate is beyond me. I’m not going to pretend to be an engineer here, but it’s an obvious wear item since it is made of the softer metal. I would wager whatever side is worn the worst is the axle that sees the most work with the open type diff these trucks run. 

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