4x4 wont engage

[surreyboy]

hey guys , just wondering if anyone can help me out or give me some helpful tips/advice as to what might be happening here . my truck 97 , F250 , HD , 7.3L , ext cab , long box ,4x4
was pulling quad trailer in the snow & wanted to cross a hwy so i locked the hubs & put it in 4x4(hi) to hook up to get across hwy with out causing a accident or getting T-boned . was a slight clunk when 4x4 engaged , crossed , unlocked hubs , put back into 2 wheel & continued on got to a gravel road with deep snow , got out to lock hubs , put it in 4x4(hi) another light clunk but this time the front wheels weren't hooking up , just the rear wheels ?? got out turned hubs a few more times to make sure that they were in the right position & moved the 4x4 shifter back & forth but still no 4x4 ? any one have any suggestions as to what this might be ? could it just be something simple as the cotter pins in the hubs shearing ??

thanks to every one !

[madpogue]

Gotta look under and see what is and isn't turning. You'll need an assistant. First do it in 4HI with the hubs unlocked. See if that makes the front driveshaft turn. Then jack up each front wheel and turn it with the hub unlocked, then again with the hub locked. The U-joint should turn with the hub locked.

Did you try 4LO, just for grins?

[surreyboy]

no , i didnt try 4 lo , i didnt want to mess around too much being that i was too far from home/civilization...
your talking the universals on the front just inside the spindles right ? with the hubs locked & the 4x4 put into 4 hi or lo the universals should spin by manually rotating the tires ?

thanks !

[madpogue]

Yes, that's the u-joint to watch. If you jack up a front wheel and try to spin it in 4HI with the hubs locked, it should not turn. Try it with just that hub locked, and with the t-case in 2HI, just to see if the u-joint turns. This tests each locking hub in isolatio.

[surreyboy]

ok , i was able to check the front drive shaft , it spins while in 4 hi & hubs locked but the 4x4 will not engage.....there manual lockers too if that makes a difference ?
i also popped the caps off the hubs & there was small pices of what looked like some sort of cast aluminum or metal ?

[madpogue]

Did you try spinning the axle shafts? Try each one, hub locked and unlocked. If either one spins while its accompanying hub is locked, that hub has failed. 'Course, if they're fairly "experienced", it's probably prudent to replace both.

[ZMANN]

there manual lockers too if that makes a difference ?
i also popped the caps off the hubs & there was small pices of what looked like some sort of cast aluminum or metal

Well I think He exploded His manual hub LOL